Temporal Consciousness
In ordinary conscious experience, consciousness of time seems to be ubiquitous. For example, we seem to be directly aware of change, movement, and succession across brief temporal intervals. How is this possible? Many different models of temporal consciousness have been proposed. Some philosophers have argued that consciousness is confined to a momentary interval and that we are not in fact directly aware of change. Others have argued that although consciousness itself is momentary, we are nevertheless conscious of change. Still others have argued that consciousness is itself extended in time. In this entry, the motivations and merits of these and other positions will be expounded and assessed.
- 1. Three Models of Temporal Consciousness
- 2. A Brief History
- 2.1 Augustine
- 2.2 Locke, Berkeley and Hume
- 2.3 Thomas Reid: common sense champion of PT-antirealism
- 2.4 Kant and Brentano: the emergence of Retentional models
- 2.5 Meinong and Stern: the emergence of the Extensional alternative
- 2.6 Hodgson, James and the Specious Present
- 2.7 Bergson, Husserl, Russell and Broad
- 3. Further Issues and Distinctions: Simultaneity, Immediacy and Continuity
- 4. Cinematic Models
- 5. Extensional Models
- 6. Retentional Models
- 7. Metaphysics of Temporal Consciousness
- Bibliography
- Academic Tools
- Other Internet Resources
- Related Entries
1. Three Models of Temporal Consciousness
1.1 Time and Consciousness
Time and consciousness are interwoven on several levels. From the vantage point of ordinary life and common sense, consciousness plainly seems to exists in time. When we hear the clock strike twelve, our auditory experience of it so doing also occurs at twelve (or at most a few moments later). Watching a 120 minute action movie results in a two hour stream of auditory and visual experiences (along with accompanying thoughts and feelings), and this stream runs concurrently with the playing of the movie. Quite generally, our conscious states, irrespective of their kind or character, seem to occur in the same temporal framework as the events in the wider world – even if their precise timing is not easy to ascertain. But this is by no means the whole story.
Our consciousness may be located within time, but there are also ways in which time or temporality might be regarded as manifest within consciousness. While watching a two hour movie, we will generally remain aware how much of the two hour period remains, even if we are paying no attention to the plot. We can judge the duration of temporal intervals, particularly short ones, with reasonable accuracy – an ability that psychologists have investigated in considerable detail (see Wearden 2016 for an overview). Our episodic (or autobiographical) memories supply us with access to our own pasts; thanks to such memories our earlier states of consciousness are not altogether lost to us: they can be recreated (or relived), albeit imperfectly, in our present consciousness. And of course there are past-oriented emotions, such as remorse or regret or shame: through these the past can influence our present feelings, often in powerful ways. While there is no future-directed counterpart of memory, we can anticipate future happenings (more or less accurately, more or less eagerly), and experience future-directed emotions: fear, dread, hope – and these too can exert a powerful influence of our present states of consciousness.
The story is still by no means complete, for temporality is manifest in consciousness in a further and more intimate way. In our ordinary experience, over brief intervals, we seem to be directly aware of temporally extended phenomena such as change, persistence and succession. When we see a friend waving goodbye, do we infer that their arm is moving, on the basis of having observed a motionless arm occupying a sequence of adjacent spatial location? We do make such inferences of this kind: if I see that my neighbour’s dustbin is in the middle of the road rather than its usual position on the pavement, I (rightly) infer that it has been moved. But the case in question is not at all like this: what we see is simply an arm in motion. (Is it for nothing that cinema is often called ‘the moving image’?) The same applies in other sensory modalities. When listening to a melody, we hear each note giving way to its successor; when we hear a sustained violin tone, we hear the tone continuing on, from moment to moment. If temporally extended occurrences such as these can feature in our immediate experience, it is natural to conclude that our awareness must be capable of embracing a temporal interval.
While this may seem obvious, it can also seem problematic. We can remember the past and anticipate the future, but we are only directly aware of what is present – or so it is natural to say and suppose. But the present, strictly speaking, is momentary. So if our awareness is confined to the present, our awareness must itself lack temporal depth. Hence we are led swiftly to the conclusion that our direct awareness cannot possibly encompass phenomena possessing temporal extension. We are thus confronted with a conundrum: it seems our awareness must extend over time, but it seems it can’t.
In grappling with this ‘paradox of temporal awareness’ as it is sometimes called, different philosophers have proposed quite different accounts (or models) of the structure of this form of temporal consciousness. Simplifying somewhat, the most commonly favoured options fall into three main categories:
Cinematic Model: our immediate awareness lacks any (or any significant) temporal extension, and the same applies to the contents of which we are directly aware – they are akin to static, motion-free ‘snapshots’ or ‘stills’. Our streams of consciousness are composed of continuous successions of these momentary states of consciousness. In this respect they are analogous to movies, which (as displayed) consist of rapid sequences of still images.
Retentional Model: our experiencing of change and succession occurs within episodes of consciousness which themselves lack temporal extension, but whose contents present (or represent) temporally extended intervals and phenomena. These episodes thus have a complex structure, comprising momentary phases of immediate experience, along with representations (or retentions) of the recent past. Our streams of consciousness are composed of successions of these momentary states.
Extensional Model: our episodes of experiencing are themselves temporally extended, and are thus able to incorporate change and persistence in a quite straightforward way. Our streams of consciousness are composed of successions of these extended ‘chunks’ of experience.
These labels are not standard – in this field there is little by way of terminological uniformity – but for present purposes they will serve (see Kon and Miller (2015) for a more fine-grained categorization). All three models are depicted in Figure 1 below. In each of the diagrams the horizontal line represents ordinary clock-time. Although the Retentional and Cinematic models both trade in momentary (or very brief) states of consciousness – in the diagrams such states are represented by thin vertical lines – these states are construed very differently. In the Cinematic case the momentary contents seem momentary, and are static (they contain no discernible motion or change); in the Retentional case the contents appear to possess a brief temporal depth, containing as they do experienced change and succession – hence the backward pointing arrows, intended to signify the way in which the recent past is supposedly ‘retained’ in present consciousness.
Figure 1. The Three Main Conceptions of Temporal Consciousness.
In his influential writings on these matters William James argued that to make sense of our temporal experience we need to distinguish the strict (or mathematical) present from the from the experiential (or specious) present: whereas the first is indeed durationless, the second possesses a brief duration, sufficient to accommodate the change and persistence we find in our immediate experience. The Retentional and Extensional approaches can each be seen as implementing James’ proposal, albeit in very different ways.
Ascertaining where the truth lies among the differing accounts of the temporal contents of our immediate experience is interesting and intriguing in itself. Although most forms of experience seemingly feature succession and persistence – even the most primitive forms if James was correct in characterizing infant consciousness as a ‘blooming, buzzing confusion’ – it is not easy to understand how any form of experience can have such features. The interest and importance of the debate does not end here, for each of the accounts of temporal awareness on offer has significant, and very different, implications for our understanding of the general structure of consciousness. In this entry we will be exploring the principle features and motivations of the competing accounts, as well as their strengths and weaknesses.
1.2 Terminology, Problems and Principles
Although proponents of all three approaches are attempting to make sense of our experience of temporally extended phenomena, there are divergences on the issue of how precisely this experience should be construed, and on several related matters.
One significant divide is between those who believe that temporally extended phenomena really do figure in our immediate experience, and those who deny this. To coin some terminology:
Phenomeno-temporal Realism (PT-realism, sometimes further abbreviated to realism): change, succession and persistence can be directly perceived or apprehended.
Phenomeno-temporal Antirealism (PT-antirealism, sometimes further abbreviated to antirealism): change, succession and persistence cannot be directly perceived or apprehended.
The Extensional and Retentional models are the two principle forms of PT-realism. Proponents of the Cinematic model can subscribe to realism, but most do not. The task facing PT-antirealists is in one respect the easier of the two: unlike their realist counterparts, they are under no obligation to provide an intelligible account of how it is possible for our consciousness to embrace temporally extended phenomena. But in another respect their task is the more difficult. Antirealists are under an obligation to ‘save the (temporal) phenomena’: they need to supply a credible explanation as to why it seems so natural to say we perceive movement and change when, in actual fact, we do no such thing.
For realists it is important to distinguish the experience of succession from a mere succession of experiencings. An experience of succession involves a temporal spread of contents being presented together in consciousness, albeit in the form of a perceived succession rather than simultaneously. Hence both Extensional and Retentional theorists agree that a temporal spread of contents can be apprehended as a unity. To introduce some further terminology:
The Diachronic Unity Thesis: simultaneous contents can be experienced together, but so too can contents that appear to be successive (at least over short intervals).
Contents which are apprehended as unified in this way belong to a single specious present. Note the ‘appear to be successive’. This is needed to accommodate Retentional specious presents: although on a phenomenological level these seem to possess temporal extension, in reality they are housed in episodes of experiencing which are momentary, objectively speaking. Extensional theorists, by contrast, regard specious presents as extending a short distance through ordinary clock-time, in just the way they seem to.
2. A Brief History
2.1 Augustine
The confinement of immediate experience to a momentary present has a long and distinguished pedigree. In the preamble to his Lectures on the Consciousness of Internal Time Husserl tells us ‘The analysis of time-consciousness is an ancient burden for descriptive psychology and epistemology. The first thinker who sensed profoundly the enormous difficulties inherent in this analysis, and who struggled with them almost to despair, was Augustine’ (1991: 3). Irrespective of whether he was the first to dwell on such matters, Augustine’s labours in Book XI of the Confessions led him to espouse a position that is at least highly suggestive of the Cinematic conception outlined in §1. Augustine subscribed to the doctrine of Presentism (as it has latterly become known), i.e., he held that only what is present is real:
What now is clear and plain is, that neither things to come or past are. Nor is it properly said, “there be three times, past present and to come:” yet perchance it might be properly said, “there be three times: a present of things past, a present of things present, and a present of things future.” For these three do exist in some sort, in the soul, but otherwhere do I not see them; present of things past, memory; present of things present, sight; present of things future, expectation. (Gale 1968: 44)
Since for Augustine it was also clear that the present must be entirely without duration, and that our perception is restricted to what is present – ‘that only can be seen, which is’ (Gale 1968: 43) – we are led swiftly to the conclusion that we can perceive or experience only what is contained in a momentary present.
Augustine went further. If our consciousness is confined to the momentary present, how is it possible for us to know as much as we do about the duration of events or processes we live through? Augustine’s solution to this problem turns on the way memory and expectation can interact. For illustrative purposes he envisages himself on the verge of reciting a familiar Psalm. Before starting to speak all the verses are laid out before him in the form of expectations concerning what he is about to say; when part-way through his performance, the reciting of some verses is transferred from expectation to memory; as he continues to speak this transfer continues until the whole of the Psalm passes into memory: ‘thus the life of this action of mine is divided between my memory as to what I have repeated, and expectation as to what I am about to repeat.’ (Gale 1968: 52). Analogous considerations apply over shorter timescales (the experiencing of individual sounds and syllables) and over longer periods (a person’s entire life).
As we shall see, this reliance on a combination of momentary perceptual experience, memory and expectation in explaining our experience of temporality is typical of PT-antirealists.
2.2 Locke, Berkeley and Hume
Since we evidently possess concepts of persistence, succession and suchlike, one would expect philosophers who believe that our basic concepts derive their content from the content of our immediate experience – philosophers such as Locke, Berkeley and Hume – would incline in the direction of realism. And generally speaking, albeit with certain complications, this is what we find. In the Enquiry (1690) Locke writes:
It is evident to anyone who will but observe what passes in his own mind, that there is a train of ideas which constantly succeed one another in his understanding, as long as he is awake. Reflection on these appearances of several ideas one after another in our minds, is that which furnishes us with the idea of succession: and the distance between any parts of that succession, or between the appearance of any two ideas in our minds, is what we call duration. (Chapter XIV, 3)
As it stands, the import of this passage is not entirely clear, for it is not entirely clear what Locke mean when he talks of our ‘reflecting’ on successions of ideas (i.e., experiences). If reflection simply means introspection – i.e., the directing of our attention, the focusing of our introspective awareness – then for Locke succession is something of which we are directly aware. If ‘reflecting’ means ‘think about’ in the sense of reason about, there is no such implication. Other passages from the Enquiry tend to confirm the introspective construal. When explicitly defining ‘reflection’ Locke links it closely to attentive awareness: ‘By REFLECTION … I would be understood to mean, that notice which the Mind takes of its own Operations, and the manner of them, by reason whereof, there come to be Ideas of these Operations in the Understanding.’ (II, 1, 4) The introspective interpretation gains further support in this passage:
31 …. I think it is plain, that from those two fountains of all knowledge before mentioned, viz. reflection and sensation, we got the ideas of duration, and the measures of it. For, first by observing what passes in our minds, how our ideas there in train constantly some vanish and others begin to appear, we come by the idea of succession. Secondly, by observing a distance in the parts of this succession, we get the idea of duration.
Given that Locke’s defines consciousness itself as ‘the perception of what passes in a Man’s own mind’ (II, 1, 19), if we can observe (and hence perceive) succession in our own minds, we are surely conscious of it too.
The case for taking Locke to subscribe to realism looks strong.[1] Remarks along very similar lines can also be found in Berkeley: in section 98 of The Principles of Human Knowledge (1710) he tells us that ‘Time therefore [is] nothing, abstracted from the succession of ideas in our minds’. Hume’s position on the origin of our concept of succession is likewise broadly similar to that of Locke. In Book 1, Part II(§3) of his Treatise (1739) he writes:
… time cannot make its appearance to the mind, either alone, or attended with a steady unchangeable object, but is always discovered by some perceivable succession of changeable objects. (Treatise: 35)
… Five notes played on a flute give us the impression and idea of time; though time be not a sixth impression, which presents itself to the hearing or any other of the senses. (ibid., 36)
… the indivisible moments of time must be filled with some real object or existence, whose succession forms the duration, and makes it conceivable by the mind. (ibid., 39)
Although Hume agrees with Locke over the origin of our concept of succession, what he says about duration sits uneasily with Locke’s contention that we arrive at the latter concept by observing the distances between impressions. For Hume,
… the idea of duration is always derived from a succession of changeable objects, and can never be conveyed to the mind by any thing steadfast and unchangeable…. since the idea of duration cannot be derived from such an object, it can never in any propriety or exactness by applied to it, not can any thing unchangeable be ever said to have duration. (ibid., 37)
Since a period of (total) silence between the hearing of two sounds would not itself contain any change or succession – at least of an auditory kind – the concept of duration cannot be derived from this period of silence, or so Hume maintains. For an ingenious attempt to derive a consistent doctrine from Hume’s various (sometimes puzzling) remarks on time and temporal concepts in the Treatise see Baxter (2007); for further useful discussion see Bardon (2007).
2.3 Thomas Reid: common sense champion of PT-antirealism
Thomas Reid also takes issue with some of Locke’s claims in his Essays on the Intellectual Powers of Man (1785). For Locke succession is a more basic concept than duration – since we arrive at the concept of duration by reflecting on the distances between parts of successions – but Reid argues the reverse is the case. For a succession to exist at all, its parts – either particular impressions or the intervals between them – must themselves already have duration: for if these parts were all entirely lacking in duration, we would be dealing with a purely momentary phenomenon, and hence something which could not contain any kind of succession. Hence succession presupposes duration, and not vice-versa.
Reid’s second complaint concerns the role Locke assigns to reflection, construed as the awareness we have of the contents and operations of our own minds. Reid doesn’t dismiss this use of the term as illegitimate, but he does suggest it is a good deal narrower than the ordinary (and thus more proper) use, which allows reflection to encompass reasoning, judging, and remembering what is past. The latter is of particular relevance, for Reid goes on to argue without memory to inform us of what we have already experienced, we could never arrive at a concept of succession. Consequently, since ‘reflection’ construed in Locke’s narrow, quasi-technical way doesn’t involve memory, Locke was mistaken in thinking that reflection – of this sort at least – could ever furnish us with our concept of succession.
In arguing thus Reid is evidently assuming that our direct awareness is incapable of spanning even a brief temporal interval: if it could, we could directly apprehend successions, without relying on memory. His argument for this assumption is succinct, and on the face of it, quite plausible:
It may here be observed that, if we speak strictly and philosophically, no kind of succession can be an object either of the senses or of consciousness; because the operations of both are confined to the present point of time, and there can be no succession in a point of time; and on that account the motion of a body, which is a successive change of place, could not be observed by the senses alone without the aid of memory. (Intellectual Powers, Essay III, chapter V)
Since the claim that we are immediately aware only of what is present can seem common sense of the plainest sort, it is not surprising to find Reid endorsing it, and hence rejecting realism in favour of the antirealist alternative. Reid recognizes that it seems equally common sensical to say that we see bodies move – after all, we often talk in such terms: e.g., ‘I saw her waving her arm’. In response he argues that such talk is perfectly legitimate, provided it is construed in loose or popular sense, and not taken strictly and literally.
2.4 Kant and Brentano: the emergence of Retentional models
So far as the perception of change is concerned, matters are by no means as clear-cut as Reid suggests. Endorsing the plausible-seeming Augustinian doctrine that consciousness is confined to the present point of time does not oblige one to reject the (equally plausible) claim that change and succession feature prominently in immediate experience. These claims are quite compatible with one another provided the experience of change occurs within the confines of the momentary present. Indeed, in the eyes of some – but not all – this confinement is a necessary precondition for contents to be experienced together. For according to one influential line of thinking regarding phenomenal unity, in order for contents to be experienced as unified, they must be presented simultaneously to a single momentary awareness.
The obvious way of developing an account along these lines is to hold that momentary episodes of sensory consciousness are accompanied by a simultaneously existing array of representations (or retentions) of immediately preceding conscious states, and our awareness – at a single moment of time – of this combination of ingredients provides us with (what we take to be) a direct awareness of change and succession. Kant propounds something alone these lines in ‘The Synthesis of Reproduction in Imagination’ from the first Critique (1787):
… experience as such necessarily presupposes the reproducibility of appearances. When I seek to draw a line in thought, or to think of the time from one noon to another, or even to represent to myself some particular number, obviously the various manifold representations that are involved must be apprehended by me in thought one after the other. But if I were always to drop out of thought the preceding representations (the first parts of the line, the antecedent parts of the time period, or the units in the order represented), and did not reproduce them while advancing to those which follow, a complete representation would never be obtained: none of the above-mentioned thoughts, not even the purest and most elementary representations of space and time, could arise. …. the reproductive synthesis of the imagination is to be counted as among the transcendental acts of the mind. We shall therefore entitle this faculty the transcendental faculty of imagination. (A102, Kemp Smith: 133)
Kant here is concerned with the necessary preconditions for thought (or cognition) as well as perceptual experience, and his overall line of argument is complex.[2] However, it is easy to grasp (at least part of) what he has in mind. Anyone who inclines to realism, but also follows Augustine in confining consciousness to the momentary present, faces the difficulty of explaining how we can have an awareness of succession if our consciousness consists of nothing more than a succession of momentary snapshot-like experiences. Kant solves this problem by offering a richer account of these momentary states of consciousness. In the visual case, momentary episodes of visual experiencing are accompanied by representations of recently experienced visual contents. More generally, these representations (or retentions) allow us to be aware that our presently occurring experience is a part of an ongoing process.
More needs to be said, but Kant supplies at least the beginnings of one plausible-looking account of how it might be possible for us to be aware of change and succession in the way we seem to be. This ‘Retentional’ approach – recalling the terminology of §1.1 – soon found other advocates, and is comparatively commonplace by the end of the nineteenth century. Brentano recognized that reaching a clear understanding how it is possible for us to directly experience succession and persistence is central issue for phenomenology (or ‘descriptive psychology’ as he preferred to call it). He also recognized that a mere succession of experiences does not, in and of itself, add up to an experience of succession. Brentano’s solution is reminiscent of Kant’s: when listening (say) to an extended tone or melody, he argued, at each moment you are aware of a momentary sound-phase, in the form of a momentary auditory sensation, but you are also (and simultaneously) aware of a series of representations (or retentions) of the immediately preceding phases. The latter Brentano referred to as proteraesthesis. In lectures in Würzburg in 1873 Brentano illustrated what he had in mind with a diagram, similar to the one depicted in Figure 2, which depicts the experiencing of a melody.
Figure 2. Brentano on hearing a melody.
The horizontal line a-b-c-d corresponds to a continuous flow of ongoing auditory sensations; the vertical lines correspond to the proteraestheses which accompany these sensations at three particular points b, c an d. As can be seen, as we move from b to c to d, the proteraestheses gradually increase in complexity, with the result that the hearing of d is accompanied by representations of preceding tone-phases stretching right back to a, but no further: this is the limit of the experienced present. Although in this last episode representations of a, b and c are experienced together with d, these tone-phases are not experienced as simultaneous – i.e., as a chord – rather, they are experienced as a succession. This gives rise to several questions. How can contents which are simultaneous, objectively speaking, seem to be successive? What is the precise nature of the representations occurring in proteraestheses?
Brentano’s views on these matters underwent several changes. In his earlier writings, he held that proteraestheses are filled with non-existent (purely intentional) objects; the latter are apprehended under a ‘modifying attribute’ which results in their (seemingly) possessing a certain degree of pastness. He came to view this is as mistake, and in later writings he argued that the difference between the content of a proteraesthesis and an ordinary (present) sensation lies not in the nature of the object of which we are aware, but rather the way in which we are aware of it – there are ‘temporal modes of consciousness’. Initially he construed these temporal modes in terms of differences in judgement (a represented content a is judged be past to a certain degree); in the final phase of his thought he opted instead for temporal modes of presentation: sensory objects can be apprehended as past to differing degrees. See Chisholm (1981) and Kraus (1976) for further details.
2.5 Meinong and Stern: the emergence of the Extensional alternative
In his account of how it is possible for us to perceive a temporally extended phenomena such as a melody, Meinong (1899) defended a Retentional conception of time consciousness along the same general lines as Brentano’s, but he also emphasised some relevant distinctions.
Meinong points out that the temporal properties of the objects we perceive need not coincide with the temporal properties of the presentations (or episodes of awareness) in which we apprehend them: e.g., objects which are past can be presented in the present. A further distinction concerns ‘temporally distributed’ and ‘temporally undistributed’ objects. An entity is temporally distributed if its existence is spread over time, it is temporally undistributed if its existence is confined to a single moment. It is natural to think that a temporally distributed process such as a melody is perceived via a sequence of presentations which are themselves temporally distributed – presentations which run concurrently, or in parallel, with what is presented. However, this natural or naïve picture is also problematic: since a succession of presentations does not amount to a presentation of succession, something further is needed. For Meinong, as for Brentano, the way forward is dictated by a necessary constraint on experienced unity: for contents to make up a perceived succession they must be presented simultaneously, to a single momentary act of apprehension. So it turns out that, contrary to the naïve view, temporally distributed objects are apprehended by episodes of experiencing which are themselves non-distributed.
The naïve view rejected by Meinong may have its problems, but it also has its defenders. The psychologist L.W Stern criticised Meinong’s own preferred model on phenomenological grounds. We are seeking an account of how we can directly perceive change and persistence. Meinong locates the perception of succession in reproductions of previously experienced contents, housed in momentary episodes of experiencing. How can apprehending these reproductions (or retentions) deliver a full-blooded perception of succession? The only way to achieve what is needed is to allow successions of properly perceptual contents to be directly apprehended. For Stern this means acts of apprehension must be temporally distributed:
That only those contents can belong to a whole of consciousness that exist together and are simultaneously present at any given time … is a dogma, which, in a more or less veiled form, determines numerous psychological reflections. I consider this dogma, at least in this generalized form, to be false. I believe that there are instances when an apprehension first comes into being on the basis of temporally extended content of consciousness, in such a manner that every part of this content exists in an insoluble connection with every other part. It is only in this and through this connection that the characteristic resulting act can be produced without, however it being the case that every part has to exist simultaneously, or as an after-duration. … It appears to me unjustified to take apart such a distinctive content of consciousness and dissect it into artificial elements simply because it is not completed in a moment … (Stern, 1897/2005, 313)
So for Stern the episodes of experiencing in which temporally extended phenomena are apprehended are themselves temporally extended. The doctrine that diachronic phenomenal unity can only exist in strictly momentary states of consciousness is rejected in favour of a more natural (or naïve) model of temporal awareness.
I therefore put forth the following principle: mental events that play themselves out within a stretch of time can under circumstances form a unified and complex act of consciousness regardless of the non-simultaneity of individual parts. That stretch of time over which a mental act can be extended I call its presence-time. (1897/2005, 315)
This ‘Extensional’ approach – again recalling the terminology of §1.1 – has the definite advantage of allowing change to be perceived in as immediate manner as one might wish for. In subsequent years variants of it will be defended by Mundle (1966), Foster (1979, 1982, 1991), Dainton (2000/2006, 2003, 2008, 2014), Hoerl (2013b), Phillips (2010, 2014b), Rashbrook (2013), Soteriou (2010). However, although it has its advantages, this model also faces difficulties. How is it possible for contents that are all experienced together, and also as present, seemingly to occur in succession rather than simultaneously? Meinong pointed out a further potentially significant problem. In virtue of what are the successive phases of a temporally extended episode of experiencing unified? What prevents a temporally distributed awareness from also being a fragmented one? This is a difficulty Brentano, Meinong and other Retentional theorists avoid: if the experience of succession is housed in momentary states of consciousness, the problem of securing diachronic unity for temporally distributed experiencings simply does not arise. Allowing consciousness to extend through time may bring advantages, but it is not without costs.
2.6 Hodgson, James and the Specious Present
The last decades of the 19th century saw the Retentional form of realism also finding favour in Anglophone circles. James Ward’s ‘Psychology’ entry for the ninth edition of the Encyclopaedia Britannica (1886) includes the following account of the experience of succession: ‘In a succession of events, say of sense-impressions A B C D E … the presence of B means the absence of A and of C, but the presentation of this succession involves the simultaneous presence, in some mode or other, of two or more of the presentations A B C D. In presentation … all that corresponds to the differences of past, present and future is in consciousness simultaneously’. The second chapter of Shadworth Hodgson’s The Metaphysic of Experience (1898) contains a detailed phenomenological analysis of what is involved in hearing a succession of tones C-D, and the account Hodgson develops there is clearly along Retentionalist lines: “In this sequence, when we are actually hearing D, we are actually not hearing but remembering C … the content of C being now continued, but with less vividness, into the portion of the process occupied by D thereby becoming a representation of C which is no longer heard as a presentation.” (1898: 70–72)
Both Ward and Hodgson are cited by William James in his influential chapter ‘The Perception of Time’ in his Principles of Psychology (1890). It was thank to James discussion that ‘the specious present’ entered the vocabulary of both philosophers and psychologists. James gives E.R. Clay credit both for the term, and for recognizing that the ‘sensible present’ has duration; he quotes him thus:
The relation of experience to time has not been profoundly studied. Its objects are given as being of the present, but the part of time referred to by the datum is a very different thing from the conterminus of the past and the future which philosophy denotes by the name Present. The present to which the datum refers is really a part of the past – a recent past – delusively given as being a time that intervenes between the past and the future. Let it be named the specious present, and let the past, that is given as being the past, be known as the obvious past. All the notes of a bar of a song seem to the listener to be contained in the present. All the changes of place of a meteor seem to the beholder to be contained in the present. At the instant of the termination of such series, no part of the time measured by them seems to be a past.
While it is not clear from this passage quite how Clay construed the specious present, it evidently has some apparent duration – enough to contain the seeing of a shooting star – hence its difference from the strict (durationless or mathematical) present.[3] James claimed the latter to be ‘an altogether ideal abstraction, not only never realized in sense, but probably never even conceived of by those unaccustomed to philosophic meditation.’ (1890: 608) For James the only present with experiential reality is the specious present: ‘the original paragon and prototype of all conceived times is the specious present, the short duration of which we are immediately and incessantly sensible.’ (1890: 631) In another formulation he enters into more detail, and says something about what this short duration contains:
the practically cognized present is no knife-edge, but a saddle-back, with a certain breadth of its own on which we sit perched, and from which we look in two directions into time. The unit of composition of our perception of time is a duration, with a bow and a stern, as it were – a rearward – and a forward-looking end. It is only as parts of this duration-block that the relation of succession of one end to the other is perceived. We do not first feel one end and then feel the other after it, and from the perception of the succession infer an interval of time between, but we seem to feel the interval of time as a whole, with its two ends embedded in it. (1890: 609–10)
James’ specious present and Stern’s ‘presence-time’ obviously have much in common – both are intended to designate the brief temporal window through which we are directly aware of change and persistence – but in one respect they are very different. Stern construed this window in an Extensionalist way, as extending over a brief interval of ordinary time. James, by contrast, followed Ward and Hodgson and subscribed to a Retentional interpretation. Or at least he did so in the Principles, in other writings a different story is told; see Section 3 of the supplementary document The Specious Present: Further Issues for more on the interpretation of James.
Although Hodgson’s analysis of experiencing a sequence of tones is clearly Retentionalist in spirit – see Anderson (2017) for more on this – what he says in the course of his analysis of the experiencing of a single C-tone in the Metaphysic suggests his position may be more complex. Here Hodgson stresses that no matter how brief the C-tone might be it will have some experienced duration, and so will consist of an experienced transition between earlier and later phases, even if these are very difficult to discern in introspection. Although these elementary durations will also feature retentions, they are of a distinctive kind:
It is implied in the term empirical, as applied to any portion of experience, that this portion has some time-duration; and from this it follows, that the least possible empirical present moment is one, in which perception and memory (in the sense of simple retention) are indistinguishable from one another. (1898: 60)
… memory in its essential characteristic, namely retention of a past in a present moment, now has been shown to take its place among the ultimate facts of experience, being involved in the simplest cases of perception, for which in fact, it is but another name. (1898: 71)
In the context of the experiencing of C-D, Hodgson holds that retention of C is definitely not a presentation, but rather a less vivid “representation” of C that is experienced with D. In the case of the single tone C, the retention of the earlier phase is quite different: it is indistinguishable from perception, or perception by “another name”. Since Hodgson quotes the second passage in clarifying his position in an exchange with Stout (Hodgson 1900), he evidently believed it to be of some importance.
Although his terminology could have been clearer, Hodgson may well have been conceiving of the single brief C-tone experience in an Extensionalist manner, i.e. as being wholly perceptual in character, even though it is temporally extended. In which case, by also holding that these brief perceptions are accompanied by retentions, he was in fact adopting a hybrid model of temporal experience that incorporates elements of both Extensionalism (over short intervals) and Retentionalism (over larger intervals).
2.7 Bergson, Husserl, Russell and Broad
As Canales (2015) vividly demonstrates, around the turn of the 20th century Bergson’s writings on time and consciousness had considerable influence. In his Time and Free Will: An Essay on the Immediate Data of Consciousness (1889/1910) he began his campaign against the ‘spatializing’ of time, and in this campaign the concept of duration (or durée) plays a key role. At least in his earlier writings, this concept applies to time as it is features in our immediate experience. For Bergson, duration is a continuous flow, immeasurable and unquantifiable – the ‘ceaselessly seething surd at the heart of things’, in Barrett’s words (1968: 373). As such it is radically unlike the static conception of time as a manifold of mere locations to be found in the scientific conception of the world, whether Newtonian or Einsteinian.
Pure duration is the form which the succession of our conscious states assumes when our ego lets itself live, when it refrains from separating its present state from its former states … We can thus conceive of succession without distinction, and think of it as a mutual penetration, an interconnexion and organization of elements, each one of which represents the whole, and cannot be distinguished or isolated from it except by abstract thought. Such is the account of duration which would be given by a being who was ever the same and ever changing, and who had no idea of space. But, familiar with the latter idea and indeed beset by it, we introduce it unwittingly into our feeling of pure succession; we set our states of consciousness side by side in such a way as to perceive them simultaneously, no longer in one another, but alongside one another; in a word, we project time into space, we express duration in terms of extensity, and succession thus takes the form of a continuous line or a chain, the parts of which touch without penetrating one another. (Bergson 1910: 100–101)
Many of Bergson characterizations of duration are negative: he tells us a good deal about what it is not, but comparatively little about what it actually is. While this can sometimes be frustrating, there is a rationale for it: Bergson held that any attempt to conceptualize the flux of consciousness could succeed only at the cost of distorting the phenomena – a doctrine which influenced William James in his later years (for more on this see Dainton (2017) and Section 3 of the supplementary document The Specious Present: Further Issues).
The early years of the 20th century see Husserl developing an account of time-consciousness along Retentional lines. Husserl attended Brentano’s lectures between 1884–6; inspired by them, he decided to devote his energies to philosophy rather than mathematics. If Husserl’s phenomenology can be viewed as a development of Brentano’s descriptive psychology, so too can his accounts of time-consciousness. In elaborating his own position, in lectures in 1904–6, although he begins with criticisms of what Brentano and Meinong had to say on the topic, the position he ends up with is along the same general lines. Husserl may not have adopted the term ‘specious present’,[4] but he did hold that we have a seemingly direct awareness of change and persistence amongst the objects and processes we perceive over short intervals. He also held, plausibly, that as our streams of consciousness flow on, we have an awareness of their so doing. As for how this is possible, he thought it must involve past phases of consciousness somehow being ‘retained in grasp’ in later moments of consciousness. In this passage we find the ‘wonder of time-consciousness’ disclosing itself to him as he hears the rumble of an approaching coach:
The perception of the sound in the perception’s ever new now is not a mere having of the sound, even of the sound in the now-phase. On the contrary, we find in each now, in addition to the actual physical content, an adumbration …. If we focus reflectively on what is presently given in the actually present now with respect to the sound of the postilion’s horn, or the rumbling of the coach, and if we reflect on it just as it is given, then we note the trail of memory that extends the now-point of the sound or of the rumbling. This reflection makes it evident that the immanent thing could not be given in its unity at all if the perceptual consciousness did not also encompass, along with the point of actually present sensation, the continuity of fading phases that pertain to the sensations belonging to earlier nows. The past would be nothing for the consciousness belonging to the now if it were not represented in the now; and the now would not be now … if it did not stand before me in that consciousness as the limit of a past being. The past must be represented in this now as past, and this is accomplished through the continuity of adumbrations that in one direction terminates in the sensation-point and in the other direction and in the other direction becomes blurred and indeterminate. (1991: 290)
At the heart of Husserl’s account is a dynamic tri-partite view of the composition of consciousness at any instant. The three components are: primal impressions, retentions (or ‘primary memories’) and protentions. Primal impressions are the live, actual experiences that occupy the momentary now. No sooner does a primal impression – e.g., a momentary tone-phase – occur than it slips seamlessly into the past. But it does not vanish from consciousness altogether: it survives in the form of a retention, which presents it as past. For Husserl, retentions are a quite distinctive form of consciousness, and differ significantly from ordinary memories. (They are also the ‘adumbrations’ mentioned in the quotation.) As new primal impressions dawn – as they gush forth from the ‘primal source-point’ of the now – the initial tone-phase continues to be retained, but as increasingly more past, until it fades from consciousness altogether. From then on, it can only be accessed through ordinary memory. As for protentions, these are the future-oriented counterparts of retentions. In some cases – e.g., when we are perceiving or remembering a familiar sequence of events – they can be quite detailed, but often they consist of nothing more than an openness to the future, an expectation that something will come. Or as Husserl puts it:
It belongs to the essence of perception not only that it has in view a punctual now and not only that it releases from its view something that has just been, while ‘still intending’ it in the original mode of ‘just-having-been’, but also that it passes over from now to now and, in anticipation, goes to meet the new now. The waking consciousness, the waking life, is a living-towards, a living that goes from the now towards the new now. (1991: 112)
Irrespective of how the forward-looking protentional aspect of consciousness is to be properly understood, this is a plausible piece of phenomenology. As we go about our business, we generally do so with an anticipative awareness – different in different circumstances, and difficult to describe – of where we are heading, or what is likely to come next.[5]
The broad outlines of Husserl’s position may be perfectly clear, but the details pose more of a challenge. Husserl’s terminology underwent regular changes: his wrote of ‘primary memory’ prior to adopting ‘retention’; rather than the ‘specious present’ or ‘presence-time’ Husserl prefers in his early writings to talk of ‘the original temporal field’; in later writings he adopts other language: ‘primal present’, ‘flowing present’, ‘living present’. This terminological evolution goes hand-in-hand with doctrinal evolutions. Husserl wrote voluminously on time-consciousness throughout his career but never found a position he was happy with for long – in his lectures from 1907–10 he found fault with the position he elaborated in the 1904–6 lectures – and he never published a definitive statement of his position. His early lectures, along with some additional material, edited by Heidegger and Edith Stein, appeared in 1928 – and in English as The Phenomenology of Internal Time-Consciousness (1964). A fuller picture emerges from the material on the topic gathered into Husserliana X. For his subsequent thinking other sources come into play: the Bernau (or L-manuscripts) contain notes on time-consciousness dating from 1917–18, and the C-manuscripts contain material on the topic from the late 1920’s to the early 1930’s. For an overview of Husserl’s changing views, over the whole of his career, see Kortooms (2002).
In Anglophone circles in the same period, the realist position was being advocated by leading figures such as Broad and Russell. According to the latter,
Succession is a relation which may hold between two parts of one sensation, for instance between parts of a swift movement which is the object of one sensation. (1913: 65)
Immediate experience provides us with two time-relations among events: they may be simultaneous, or one may be earlier and the other later. These two are part of the crude data; it is not the case that only the events are given, and their time-order is added by our subjective activity. The time-order, within certain limits, is as much given as the events. (1914: 121–2)
Broad was of much the same opinion. Writing in Scientific Thought (1923) he says: ‘There is no doubt that sensible motion and rest are genuine unanalysable properties of visual sensa. I am aware of them as directly as I am aware of the redness of a red patch.’ (1923: 287) – a clear commitment to realism. Later in the same work he elaborates thus:
it is a notorious fact that we do not merely notice that something has moved or otherwise changed; we also often seem something moving or changing. This happens if we look at the second-hand of a watch or look at a flickering flame. These are experiences of a quite unique kind; we could no more describe what we sense in them to a man who had never had such experiences than we could describe a red colour to a man born blind. (1923: 351)
Unlike Russell, who did not elaborate greatly on these matters, Broad went on provide quite detailed analyses of the structure of temporal consciousness. The account developed in Scientific Thought is of a distinctive kind. It is constructed around acts of awareness that are themselves momentary, but which apprehend phenomenal contents distributed over a short interval of time; a stream of consciousness consists of dense sequences of such acts, with the consequence that the contents apprehended by neighbouring acts largely overlap. Since Broad agrees with Stern that our consciousness extends a short distance through time his approach can be classed as Extensional. But since Broad also maintains – along with Brentano, Meinong and Husserl – that our immediate experience of change involves contents being presented to acts of awareness that are strictly momentary, it is not an Extensional view of the ordinary sort: for Stern and those in the Extensional camp, the acts of awareness (or episodes of experiencing) in which dynamic contents are apprehended are themselves temporally extended. For this reason Broad’s position is probably best classed as a Partial Extensionalism. In any event, this hybrid approach is not without its difficulties – see Mabbott (1951) – and in his later An Examination of McTaggart’s Philosophy (1938) Broad develops an account along more orthodox Retentionalist lines.
3. Further Issues and Distinctions: Simultaneity, Immediacy and Continuity
The Cinematic, Retentional and Extensional models (as sketched in §1.1) offer different and competing accounts of the structure of consciousness over those short intervals – perhaps no more than a second or so, perhaps less – during which we seem to be able to experience change and succession. Before moving on to explore these models in more detail, it is worth pausing to register in a clear and explicit way some further important theses and distinctions; some of these we have already encountered in one guise or another, others are new.
PT-realists share a commitment to the Diachronic Unity Thesis (see §1.2), i.e., the claim that contents (seemingly) spread over a short temporal interval can be experienced together. The various different ways of construing the specious present reflect a divergence of opinion as to how the Diachronic Unity Thesis can be satisfied. According to one influential view, phenomenal unity – the sort of unity which exists amongst contents that are experienced together – is confined to contents which are (objectively) simultaneous. As we have just see, Kant, Brentano, Meinong and Husserl were all of the opinion that phenomenal unity is constrained in this manner. Miller (1984: 109) supplies a label for this doctrine:
The Principle of Simultaneous Awareness (PSA): to be experienced as unified, contents must be presented simultaneously to a single momentary awareness.
Cinematic and Retentional theorists generally embrace PSA. Extensional theorists are united in their rejection of PSA: for them, experiential phenomenal unity is not necessarily confined to momentary episodes of experiencing. Hence it is possible for the experiencing of change to occur over intervals of ordinary time.
This (potential) divergence aside, both Retentional and Extensional theorists face a problem – albeit not the same problem – when it comes to handling the relationship between simultaneity and presence. Whatever their other properties, the contents of the specious present (supposedly) all seem present as and when they occur. This makes for a problem for Extensional theorists. The contents of a typical specious present will all be experienced together, as parts of a unified whole, but they will also seem to occur successively. But how is this possible? Won’t contents that are all experienced together as present appear to occur simultaneously, rather than in succession? Retentional theorists face a rather different difficulty. If we suppose, in line with Retentional doctrine, that the contents of an individual specious present are actually simultaneous, at least with regard to ordinary clock time, how can it be that they also appear successive? In slightly more formal guise:
Extensional Simultaneity Problem: how is it possible for contents which are (i) experienced together, and (ii) experienced as present, to be experienced as anything other than simultaneous?
Retentional Simultaneity Problem: how is it possible for a collection of contents which occur simultaneously to seem successive?
At first glance each of these problems may look very serious, even insuperable. It is not for nothing that many have despaired of finding a coherent account of the specious present. However, when we turn to explore the Retention and Extensional approaches in more detail, we shall see that these difficulties may not be as serious as they can initially seem.
A further issue concerns the kind of contents to be found within individual specious presents. Foster, himself a leading realist of the Extensional persuasion, writes: ‘duration and change through time seem to be presented to us with the same phenomenal immediacy as homogeneity and variation of colour through space’ (1982: 255). Broad remarks: ‘There is no doubt that sensible motion and rest are genuine unanalysable properties of visual sensa. I am aware of them as directly as I am aware of the redness of a red patch.’ (1923: 287) Broad and Foster are committed to the following general principle:
The Immediacy Thesis: change, succession and persistence can feature in our experience with the same vivid immediacy as colour or sound, or any other phenomenal feature.
The contents of Extensional specious presents – the contents apprehended as changing – are ordinary experiential contents (e.g., sounds as they feature in immediate experience). Consequently it is not surprising to find that proponents of the Extensional model generally subscribe to the Immediacy Thesis. Their Retentionalist counterparts can do so, but usually don’t – a notable exception is Lee (2014a, 2014b). Brentano, Husserl and other leading Retentional theorists hold that the contents of the specious present appear under varying ‘temporal modes of presentation’ (as they are often called). If the succession of tones [C-D-E] form a single specious present, if E seem fully or maximally present, D will appear under the mode ‘just past’, and E ‘a little more past’. On this view, each of C, D and E are experienced as parts of a unified ensemble – in conformity with the Diachronic Unity Thesis – but they are not experienced as possessing the same phenomenal immediacy.
Proponents of the Cinematic, Extensional and Retentional models are offering very different accounts of the structure and composition of our consciousness of over short periods of time. There is a further issue: what is the structure of consciousness over longer intervals? It is not unusual for us to remain awake for hours at a stretch; although the contents of our consciousness may frequently change, we can remain continuously (uninterruptedly) awake and aware for quite long periods. William James is well-known for emphasising the continuity of experience – ‘Consciousness, then, does not appear to itself as chopped up into bits. Such words as “chain” or “train” do not describe it fitly … It is nothing jointed, it flows. A “river” or a “stream” are the metaphors by which it is naturally described’ (1890: 239) – and James’ stream metaphor strikes many as apt. In the light of this new questions arise. How do the momentary static states of the Cinematic theorists combine to form extended streams of continuous consciousness of the sort we typically enjoy during our waking hours? Indeed, can they combine in the way required? Analogous questions can be posed for the specious presents posited by Retentional and Extensional theorists: how do they manage to combine to form such streams?
While the inability to answer these new questions in a satisfactory manner can certainly count against a model of temporal consciousness, the situation is complicated by the diversity of opinions concerning both the degree to which consciousness really is continuous, and manner or nature of its continuity. James himself defined ‘continuous’ as ‘that which is without breach, crack or division’ (1890: 237), but what he meant by this requires some unpacking.
It is certainly possible – and quite natural – to characterize continuity in terms of an absence of gaps: a subject S’s consciousness can be said to be continuous with respect to an interval T if S is having an experience of some kind at every moment during T. In more subjective vein, a succession of stream-phases belonging to S could be said to be continuous if S is incapable of discerning any gaps between them. For James this subjective mode of continuity was particularly important, and – perhaps controversially – he held that it is possible for streams that are objectively discontinuous (e.g., separated by a gap of minutes or hours) to be subjectively continuous.
However, for James the continuity that is characteristic of our consciousness involved more than the mere absence of gaps, whether objective or subjective. He also held that this continuity typically involves a (fairly) high degree of similarity in the qualitative character of one’s experience from moment to moment. Large and sudden variations do occur – a sudden thunderclap makes a massive difference to one’s auditory experience – but these do not usually disrupt background continuities in (say) bodily feeling, or so James argued.
The things are discrete and discontinuous; they do pass before us in a train or chain, making often explosive appearances and rending each other in twain. But their comings and goings and contrasts no more break the flow of the thought that thinks them than they break the time and the space in which they lie. A silence may be broken by a thunder-clap, and we may be so stunned and confused for a moment by the shock as to give no instant account to ourselves of what has happened. But that very confusion is a mental state, and a state that passes us straight over from the silence to the sound. The transition between the thought of one object and the thought of another is no more a break in the thought than a joint in a bamboo is a break in the wood. It is a part of the consciousness as much as the joint is a part of the bamboo. (1890: 240)
In addition to gaplessness and qualitative similarity, James recognized a further mode of connectedness between stream-phases: successive phases are linked experientially. He held that each brief phase of our stream of consciousness flows, in seamless fashion, into its successor, and that these ‘co-conscious transitions’ are themselves experienced. There is more than a hint of this in the passage just cited, but elsewhere he is more explicit. In the essay ‘A World of Pure Experience’ (1904) he writes: ‘My experiences and your experiences are “with” each other in various external ways, but mine pass into mine, and yours pass into yours in a way in which yours and mine never pass into one another’. More generally, James held that consciousness is not composed of absolutely distinct component parts (i.e., individual isolated experiences), but is ‘conjunctive’:
the parts of experience hold together from next to next by relations that are themselves parts of experience. The directly apprehended universe needs, in short, no extraneous trans-empirical connective support, but possesses in its own right a concatenated or continuous structure (1912, 7)
To coin some further terminology, on this view each brief stream-phase is experientially connected to its neighbours. Irrespective of whether it is correct, James’ contention certainly possesses prima facie plausibility: if one hears a succession of brief tones do-re-mi-fa-so, it is certainly natural to say that one also hear each tone flowing into its successor. It does not seem implausible to suppose the same holds more generally: does not each brief phase of a typical stream of consciousness seem to merge smoothly and seamlessly with its successor?
Although the Jamesian emphasis on the continuity of consciousness is widely viewed sympathetically, there are dissenters. Galen Strawson endorses realism – he believes change and succession can be directly experienced – but he also rejects James’ stream-metaphor as ‘inept’, and argues that consciousness is radically discontinuous and disjointed: ‘It is always shooting off, fuzzing, shorting out, spurting and stalling.’ (1997: 421). For Strawson there are gaps and fissures in our experience, and these are sometimes accompanied by dramatic changes in content: ‘The (invariably brief) periods of true experiential continuity are usually radically disjunct from each other in this way, even when they are not radically disjunct in terms of content.’ (1997: 422)[6] In a similar vein, Dennett holds that ‘One of the most striking features of consciousness is its discontinuity (1991: 356).
Pulling these points together, we can distinguish three main positions on the continuity issue:
The Discontinuity Thesis: although consciousness is commonly described as continuous, this is wrong: in fact our consciousness is highly disjointed, far more so than most people suppose.
The Modest Continuity Thesis: our typical streams of consciousness are indeed continuous, and this involves (i) freedom from gaps, in either or both of the senses mentioned above, and/or (ii) a significant degree of moment-to-moment qualitative similarity.
The Strong Continuity Thesis: in addition to the relationships encapsulated in the Modest Thesis, the successive brief phases of our typical streams of consciousness are experientially connected.
What divides Modest from Strong forms of continuity is the existence of directly experienced connections – James’ ‘co-conscious transitions’ – between successive stream-phases. The experienced transitions posited by advocates of Strong Continuity can plausibly be regarded as experienced changes (or successions). Since antirealists deny that change or succession can be directly experienced, they are not in a position to accept the Strong Continuity Thesis. It is otherwise for realists: since the latter hold that change and succession can be directly experienced, their position looks to be entirely compatible with Strong Continuity. However, as we shall see in due course, the situation is by no means straightforward: some realist models can accommodate Strong Continuity more easily than others.
4. Cinematic Models
4.1 Cinematic Realism
When it comes to explaining how it is possible for our consciousness to combine experiential continuity with the experience of change the account offered by the Cinematic realist is appealingly straightforward. On this view, a typical stream of consciousness consists of a close-packed, gap-free continuum of momentary (or very brief) phases. Although the contents of these phases are themselves momentary – they do not present motion or change, they are akin to static snapshots – their occurrence in rapid succession succeeds in generating all the change, succession and motion we find in our experience – or so the Cinematic realist claims. The basic feature of the model are depicted in Figure 3. On the left we see a punctual beam of awareness, the smooth, steady advance of which generates a sequence of momentary snapshot-like contents (of a falling object, in this instance), only a small selection of which is shown on the right.
Figure 3. Cinematic PT-realism: seemingly dynamic phenomenal contents are produced by an advancing ‘beam’ of awareness.
This Cinematic form of realism does not feature prominently in the literature – it was not encountered at all in the course of our brief historical survey – and with good reason: we shall see shortly that it is vulnerable to serious objections. But it nonetheless has sufficient intuitive appeal to be worth considering. By accepting that motion and change feature in our immediate experience the doctrine has the merit of taking the phenomenological data at face value. It also combines a quite natural way of conceiving of the temporal structure of consciousness – i.e., as confined to the momentary present – with an equally natural view as to the kind of content the resulting momentary episodes of experiencing could have. A camera with a fast shutter-speed (e.g., 1/10,000 of a second) will ‘freeze’ all but the fastest of motions: the facial expression of victorious sprinter at the precise moment they crossed the line can thus be revealed. If our consciousness takes the form of a series of momentary (or extremely brief) ‘exposures’, won’t the contents of our consciousness be similarly static or frozen? As an additional bonus the Cinematic realist can easily explain at least one aspect of the continuity of consciousness. If a stream of consciousness is composed of a gap-free sequence (or continuum) of momentary (or extremely brief) states, it is not surprising that we can be continually aware for hours at a stretch. The Modest Continuity Thesis (§3) is thus easily accommodated.
As for how sequences of static ‘snapshots’ can give rise to experiences which seem to possess dynamic contents, the Cinematic realist certainly has to provide a plausible account of how this comes about. Two avenues may seem promising in this regard. First, even if our awareness lacks any significant temporal depth, as it does on the proposed model, might it not be that the continuous advance of a point-like ray of awareness will generate episodes of experiencing which can encompass change and succession? By way of an analogy, think of the way a needle (or any other sharply pointed object) moved across the surface of one’s skin produces a continuous sensation of motion. Although at any one time it is only the needle’s near-dimensionless point that is in contact with our skin, we can nonetheless feel the needle moving smoothly and continuously from one location to another. Second, in the visual case, it is well known that rapid successions of static images can result in experiences of motion. The images shown on a TV or cinema screen are static snapshots, but evidently, they are perceived as dynamic: objects on a cinema screen are seen to move as smoothly and continuously as their real-life counterparts. Might not the same apply to other modes of experience, and hence to our streams of consciousness as a whole?
Unfortunately for the Cinematic realist, closer scrutiny reveals that each of these proposals is problematic. A moving ‘beam’ of awareness could produce a period of time during which experience is continuously occurring, in the sense that at each moment during the interval there is an experience being had by the relevant subject, but by itself it can produce nothing more, and – for a viable form of realism, at least – more is required. For a subject to be directly aware of a temporally extended phenomenon (such as a brief movement), adjoining phases of the phenomenon must in some manner be experienced together by the subject. As noted in §1.2, realists subscribe to the Diachronic Unity Thesis: they hold that contents that appear to occur in succession can be experienced together (or be co-conscious), in just the same way as contents which appear to occur simultaneously, at least within the confines of the specious present. But since for the Cinematic realist individual episodes of awareness are durationless, and likewise the contents apprehended in such episodes, it is difficult to see how the required Diachronic Unity can be accommodated. Since ex hypothesi our awareness does not extend beyond or between momentary episodes of experiencing, there is no scope at all for adjoining phases to be experienced together in the way required.
The point can be made a slightly different way. To employ the usual terminology, a succession of experiences is one thing, an experience of succession is quite another. Suppose there are ten people, P1, P2, P3 …  If first P1 opens their eyes momentarily before closing them again, followed immediately by P2, then by P3, all the way to P10, then we have a succession of ten experiences, each revealing the on-court action at a particular moment. But there is no experience of succession: all each person sees is a momentary still image, and these momentary experiencings are completely isolated from one another. Accordingly, the resulting sequence of experiences do not add up to an experiencing of movement or change. Although it may not be quite so obvious, the model of temporal consciousness proposed by the Cinematic realist also creates nothing more than mere succession of experiences. There are, of course, differences between the two cases, but these differences do not affect the point at issue. First, in the tennis example there are ten distinct subjects, whereas the sequence of momentary states posited by the Cinematic realist experienced by a single subject. But for this difference to matter, the momentary states enjoyed by the single subject would have to be unified within that subject’s consciousness: for if they remain discrete, experientially isolated from one another, as it were, there is no possibility of their combining to constitute an experience of succession. But with the resources available to the Cinematic realist – momentary acts of awareness, momentary contents – there is no obvious way of creating the required unity. As for the second difference, in our simple example there are but ten distinct experiences, whereas Cinematic realists will insist that on their model we are dealing with a true continuum, in the mathematical sense: we are to suppose that the perceiving of the tennis game involves an infinite number of distinct momentary experiences, not just ten. But as Bergson was fond of pointing out, numbers make no difference here: the points in the orthodox mathematical continuum are always entirely distinct from one another, no matter how close together they may be: indeed, since these points are densely ordered, between any two points there is always a further point.[7]
What of the cinematic analogy itself? Isn’t the fact that we see motion on TV and movie screens evidence that successions of motion-free images can give rise to an experience of motion? Although there is a sense in which this is correct, it is of little or no assistance to the Cinematic realist.
It is perfectly true that perceiving a succession of still images can result in a full-blooded perception of motion. If the stills which compose cinema film are shown quite slowly – say 2–5 frames per second (fps) – they are seen quite clearly as stills; if the pace picks up – to around 10 fps, they start to look somewhat blurred; if the pace picks up still further – to 20 or 25 fps – something remarkable happens: the images come alive, and we suddenly start to see genuine (and very clear, non-blurry) motion. This phenomenon – known as ‘illusory motion’ or ‘the phi phenomenon’ was first explored in the 19th century by Exner, and has been much-studied since then (not surprisingly, since it underpins televisual industries). But while it is real enough, the phi phenomenon is of little assistance to the Cinematic realist. What the latter needs is an account of how successions of momentary conscious states, each possessing entirely static contents, can give rise to the experience of motion. Static images are indeed being displayed on a cinema screen while we view a movie, but not only are these onscreen stills not themselves experiences, they do not register in our visual experience as static images: what we actually seem to see onscreen are objects in motion. Phenomenologically speaking, the stills are invisible. Given this, all the phi phenomenon clearly and unambiguously demonstrates is that a rapid succession of brief perceptual stimuli (each deriving from a brief on-screen image) can be transformed by our visual systems – after a good deal of processing – into experiences which feature motion. These perceptual stimuli are not themselves experiential in nature, consisting as they do of showers of photons (or, alternatively, patterns of electro-chemical activity on the surface of the retina).
In the absence of any plausible account of how change and succession can feature in our immediate experience, the Cinematic model cannot be regarded as a promising form of realism. Its difficulties do not end here. The Cinematic model certainly conforms to the Modest Continuity Thesis – it is compatible with our streams of consciousness being continuous in the sense of gap-free – but it is otherwise with regard to the Strong Continuity Thesis. According to proponents of the latter, the sense we have that each brief phase of our streams of consciousness flow into their successors is underpinned (or generated by) the existence of real experiential connections between such phases. It is not obvious, to say the least, how such connections could exist if all streams are composed of discrete momentary states that are experientially isolated from their immediate neighbours – see Figure 4.
Figure 4. How to satisfy (and not satisfy) the Strong Continuity Thesis.
This failure will not matter for realists who reject the full-blown Jamesian conception of streamal continuity, but for those realists who find the case for Strong Continuity compelling, the failure is a serious one.
4.2 Cinematic Antirealism
For the PT-antirealist it is a mistake to suppose that change, persistence and succession feature in our immediate experience. While this standpoint can seem wrongheaded, it can also seem the plainest common sense – or at least a consequence of plain common sense. As Augustine and Reid both recognised, it is very natural to suppose that we are only directly aware of what is going on now. If the present, strictly conceived, is the durationless interface between the past and the future – and it is commonly taken to be precisely this – the conclusion that our consciousness is confined to a durationless instant swiftly follows. As noted in §4.1, in connection with Cinematic realism, it is also quite natural to think that the content of a momentary state of consciousness will itself have a momentary character: in effect, such a content will take the form of a still, static snapshot. If this conception of both consciousness and its contents is correct, antirealism looms large on the horizon.
Irrespective of the considerations which can make antirealism an appealing doctrine, there remain the considerations, of a largely phenomenological character, which strongly favour realism. Aren’t there occasions (many of them) when we see a horse crossing a finishing line, or a car turning round a corner, or a postman walking up the garden path? Can’t we hear the explosive roar of crowd, or the sound of an approaching car, or the barking of a dog? Can’t we feel shivers running down our spine? Claims that change and movement can be directly experienced have a good deal of plausibility. What can be done to undermine these claims?
4.3 Reid on the Proper Provinces of Sense and Memory
Thomas Reid believed that our streams of consciousness are composed of sequences of momentary states; since he also believed these such states incapable of furnishing us with an genuine experience of succession (see §2.3) Reid can safely be classed as a Cinematic antirealist. Although Reid recognized that this austere position on the contents of experience is in conflict with how we normally think and talk, he also thought this conflict could be defused.
For Reid the apparent contradiction between strict philosophical truth and common sense (and common experience) is superficial: ‘It arises from this, that philosophers and the vulgar differ in the meaning they put upon what is called the present time, and are thereby led to made a different limit between sense and memory’ (1855: 236). Reid argues that our ordinary talk of ‘seeing’ things move is intelligible, at least on its own terms, because in ordinary life we generally construe the present in a loose and flexible way. If it suits our purposes – and it often does – we allow ‘the present’ to denote a period of time, rather than a durationless moment. (There is no need for the period to be short: we sometimes refer to the present decade or century.) And since temporal intervals can contain change and movement, our ordinary ways of talking are not in the least paradoxical:
… Hence it is easy to see, that, though in common language we speak with perfect propriety and truth when we say that we see a body move, and that motion is an object of sense, yet when as philosophers we distinguish accurately the province of sense from that of memory, we can no more see what is past, though but a moment ago, that we can remember what is present (1855: 236)
So far so plausible, perhaps. But a significant worry remains. How plausible is Reid’s proposed (precise, philosophical) delineation of the respective provinces of sense and memory? Realists will insist that it is questionable. To illustrate, consider the case of motion. Reid claims that ‘it is only by the aid of memory that we discern motion, or any succession whatsoever. We see the present place of the body; we remember the successive advance it made to that place: the first can, then, only give us a conception of motion, when joined to the last.’ (ibid. 237) If this is right, then when (say) we see a car turning a corner, all that is ever present in our sensory consciousness is a series of static images, each revealing the car to be at a particular location. The car’s motion, to the extent it enters our awareness at all, exists only in memories which accompany these momentary perceptions. But from a phenomenological standpoint at least, this does not ring true. The phenomenal character (the ‘what it’s like-ness’) of actually seeing a car turn a corner, and remembering (via recollected visual images) seeing an otherwise similar car turn a corner are very different indeed. Not to dwell too long on the obvious: in the perceptual case the car is clear, vivid and (seemingly) out there in the world, whereas the remembered car is far less clear and vivid, and very definitely in here (in the head, rather than out in the world). If the car’s motion is something we perceive, and it certainly seems to be, Reid’s antirealist analysis is lacking in plausibility.
In fact, the antirealist’s predicament may well be more serious still. Conflating perceived motion with remembered motion is one thing, but there is an important sense in which the antirealist is not in a position to appeal to memories of motion either. A memory-replay of a prior perceiving of motion is itself a process which unfolds over time, and – on the face of it – has a dynamic character: e.g., you see (albeit in your mind’s eye) the car sweeping round the corner. Since it would be odd to hold that motion can be remembered but not perceived, the antirealist will presumably want to analyse both forms of experience in the same sort of way. Accordingly, your visual remembering (or replay) of the car’s turning the corner will take the form of a series of static memory-images of the car at particular locations, and each of these images (save the first) will be accompanied by other static images, in the form of snapshot-like memories of the car as seen at still earlier locations. Antirealism in this form may be a more consistent doctrine, but the wholesale elimination (or reduction) of the moving to the motion-free has two consequences. First of all, it is by no means obvious how our memories could have the dynamic character they seem to possess if they consisted of nothing but still images piled on top of other still images. Second, and for present purposes more importantly, the Reid-style antirealist’s account of perceived motion is significantly weakened. Realists will argue that it is not very plausible to analyse the perceived motion in terms of momentary motion-free perceptual experiences accompanied memories of motion, but it is significantly less plausible if the relevant memories, rather than being truly dynamic, are themselves composed of entirely static images.
Although it may well be that the most compelling evidence for the realist’s claim that motion (and other forms of change) feature in immediate experience is straightforwardly phenomenological – that’s just the way our experience seems to be – there are empirical findings in psychology and neuroscience which point in the same general direction. We have already encountered (in §3.1) the phi phenomenon (or ‘illusory motion’). In the simplest of cases – as observed by Plateau in 1850 and Exner in 1875 – what is in reality a pair of lights some distance apart flashing alternately, is perceived as a single light moving back and forth. A more dramatic (and ubiquitous) illustration of the same tendency is television and cinema, where a mere 25 frames per second suffices to produce a perception of smooth motion. It seems that when our visual systems are supplied with stimuli which are merely suggestive of movement they are eager to supply us with vivid experiences of motion itself. This is not all. Studies of the visual systems in the brain have revealed areas – in particular the region known as V5 – which specialize in motion-detection. Interestingly, the condition of cerebral akinetopsia, a form of motion-blindness, has been linked to damage in the V5 area. An afflicted patient, known as LM,
reported substantial difficulty in pouring fluids into a cup or glass, because the tea, coffee or orange juice appeared “frozen like a glacier”. She could not see the fluid rising, and therefore, couldn’t establish when to stop pouring. In addition, she felt very irritated when looking at people while they were speaking: their lips appeared “to hop up and down”, so she had to look away so as not to become confused (Heywood and Zihl 1999: 3).
This too is suggestive: if, as the antirealist claims, motion never features in the immediate experience of normal human perceivers, what is it that LM has lost? (For some further details of these findings see Section 1 of the supplementary document Some Relevant Empirical Findings (Psychology, Psychophysics, Neuroscience).)
4.4 Further Diagnoses: Crick and Koch, Le Poidevin
Empirical findings along these lines by no means definitively refute the antirealist – alternative interpretations are possible – but they do make life more difficult. Rather than straightforwardly denying that we directly experience motion in the manner of Reid, the antirealist stance would be more plausible if a credible explanation as to why we believe we experience motion (and more generally, change) if in fact we do not. One route, suggested by Crick and Kock, is to find (or posit) a vector-like feature that durationless contents could possess, and which is also such as to strongly suggest or imply movement, even though no movement is actually present. According to their ‘snapshot hypothesis’ (2003: 122) – in effect, a version of Cinematic anti-realism – our consciousness not only comes in discrete chunks, the experience of motion is itself illusory:
Perception might well take place in discrete processing epochs, perceptual moments, frames, or snapshots. Your subjective life could be a ceaseless sequence of such frames … Within one such moment, the perception of brightness, colour, depth and motion would be constant. Think of motion painted onto each snapshot … (Koch 2004: 264)
Quite what is involved, at the phenomenal level, in motion being ‘painted onto’ a motionless snapshot is explained only by way of an analogy: a drawing of a person in motion (running or ice skating, say) can suggest motion, even though it is entirely motion-free. In response, realists will point out that there is a sizeable difference, phenomenologically speaking, between even looking at a still image which merely depicts motion, no matter how suggestively, and actually seeing motion. By way of further support, Koch quotes Oliver Sacks, who reports in his (1970) an occurrence of ‘cinematographic vision’ during one of his own migraine attacks:
I asked her to look at the picture, talk, gesture, make faces, anything, so long as she moved. And not, to my mixed delight, I realized that time was fractured, no less than space, for I did not see her movements as continuous, but, instead as a succession of “stills”, a succession of different configurations and positions, but without any movement in-between, like the flickering of a film (the “flicks”) run too slow. She seemed to be transfixed in this odd mosaic-cinematic state, which was essentially shattered, incoherent, atomized.
Koch approvingly cites Sacks’ suggestion that cinematographic vision – a form of akinetopsia – reveals the ‘nature of visual experience when the illusion of motion has been lost’. However, this speculation is puzzling for two reasons. The first is trivial: the designation ‘cinematographic’ is less than ideal and potentially misleading: as we have already seen (in §4.1), a plausible case can be made for holding that in a properly run cinema, the stills projected onto the screen are not themselves seen as such – all we see are the intended moving images. Second and more importantly, given the world of difference between Sacks’ motion-free experience and our everyday visual experience, in what sense can the motion we apprehend in the latter reasonably be construed as illusory? The realist will insist that if motion is an intrinsic feature of sensory experience – and it seems to be – doesn’t that suffice to ensure that it is a real feature of it too?
Le Poidevin (2007: 88–92) tentatively forwards an alternative hypothesis. As Aristotle noted, if you stare at a waterfall for a short period, and then turn your gaze to the bank beside it, you will see part of the bank (seemingly) start to move in an upwards direction. This phenomenon is commonly called ‘the waterfall illusion’ (or motion aftereffect), and the illusory motion is of an intriguing sort. You will not see a part of the bank detach itself from its surroundings and drift up towards the sky. Rather, you will see the contents within a fixed and immobile region of the bank – roughly the size of the waterfall you were staring at previously – losing their normal solidity and becoming fluid-like. Although these contents seems to be flowing upward, they do so without changing – at least in a clear and unambiguous way – their location with respect to the rest of the bank.[8] As for an explanation of what is going on in such cases, Le Poidevin (following Richard Gregory) suggests that perhaps we can discern here the workings of two distinct neural mechanisms. One ‘registers what we might call “pure motion”, i.e., gives rise to the impression of motion without any associated sense of change of position. It is this system that is responsible for the sense of perceiving motion as happening now.’ (2007: 89) A second system, relying on short-term memory, tracks and compares the alterations in location over time. This second system is not concerned with telling us about presently occurring motions, rather it gives rise to the sense that objects have changed their positions relative to one another. Hence Le Poidevin’s proposal. Perhaps our ordinary experience of motion does, after all, consist of nothing but momentary static snapshots – in accord with Cinematic antirealism – but these momentary experiences seem dynamic thanks to the activation of the ‘pure motion’ mechanism in our visual system. These snapshots do not actually feature movement, but as the waterfall illusion illustrates, movement – at least in the form of change of position over time – is not required for the vivid impression of motion.
Although this is a far more promising line for the antirealist to take – see Arstila (2016a) for a spirited defence – it also faces challenges.
As Le Poidevin concedes, it is not obvious that the proposed explanation can be generalized: even if the existence of the envisaged twin-track neural systems could be established in the visual case, there is at present no reason to think that there are corresponding systems for all the other modes of experience, and as Realists will be swift to point out, change can be heard, felt, remembered and imagined, as well as seen.[9] A second worry concerns the character of the ‘sense’ or ‘impression’ of motion delivered by the hypothesized pure motion system. These have to account for the very vivid appearances of motion in ordinary perceptions, not just the rather peculiar motions produced in waterfall-type illusions. How precisely do they do this? What is their character? There are only two obvious options. The impressions could themselves be sensory ingredients, of a visual kind, which are in some way suggestive of motion. Alternatively, they could be non-sensory: perhaps they are akin to judgements, or intuitive feelings (or convictions or beliefs), bearing a message along the lines of ‘that thing there is moving!’ The sensory option is problematic, for – as already noted in connection with Crick and Koch – it is not easy to see what feature of a still, static image could be sufficiently suggestive of motion. But the non-sensory option is also vulnerable to an objection. Realists will point out, once again, that perceived motion – both the ordinary kind, and the peculiar kind associated with motion aftereffect – exists on the level of sensory phenomena: it features prominently in our immediate experience. If this is right, the claim that motion-as-seen can be constituted of judgements or convictions, no matter how deep-seated or instinctive these might be, does not seem very plausible.
These issues about temporally dynamic contents aside, there remains the more general question of whether the Cinematic antirealist can deal in a satisfactory manner with the continuity of consciousness. If not, the Cinematic model itself would be less than fully unsatisfactory, even if it could provide a credible account of our short-term experience of motion and change. In this regard, the points made in connection with the realist version of the Cinematic approach (in §4.1) also apply to the antirealist version. Whereas Modest Continuity poses no difficulty at all, the confinement of phenomenal unity to the contents of momentary states (see Fig. 4.2) means that Strong Continuity is unattainable.
4.5 A More Radical Anti-Realism: Dennett and Chuard
Given the difficulties antirealists have encountered in doing full justice to the phenomenological considerations to which their realist counterparts give such emphasis, they may be tempted – or wise to consider – a more radical option. Perhaps there is a more dramatic discrepancy between the actual characteristics of our experience, on the one hand, and our beliefs about these characteristics on the other, than anything we have considered up to now. True, we do talk as though we see things move (and more generally, perceive change), and doubtless this talk reflects our beliefs, but perhaps our beliefs are simply wrong. Perhaps our immediate experience is in reality entirely motion-free, and our streams of consciousness radically fragmented, but since we do not believe our experience is like this, we do not talk as though it is.
With regard to the continuity issue, as noted in §3, a position along these lines has been advocated by Dennett. If asked whether our typical visual fields are fully continuous, even when one of our eyes is closed, most of us are inclined to answer in the affirmative: when we look at (say) a white wall, we see an uninterrupted expanse of white. In such cases we are certainly unable to detect a beachball-sized fuzzy dark expanse lying just to one side of the central axis of vision. But the physiology of the eye suggests there should be a ‘blind spot’ at that location, corresponding to the region of the retina occupied by the optic nerve which is devoid of light-sensitive cells. As for why we do not detect a blind region in our visual field, the standard – and on the face of it, plausible – answer is that our visual systems engage in some ‘perceptual interpolation’ or filling-in: our brains extrapolate from the stimuli reaching the light-sensitive cells in the region of the retina immediately surrounding the blind-spot, and fabricate experience to fill the relevant region of the visual field accordingly.
Dennett points out that there is alternative to this account. Rather than ‘making up’ experience in this manner, perhaps our brains simply fail to notice that there is a lack of visual information deriving from the hole-region: after all, an absence of information is not the same thing as information about an absence. Never having received information from this region, the brain simply works on the assumption that nothing special is going on there: ‘The brain doesn’t have to “fill in” for the blind spot, since the region in which the blind spot falls is already labelled (e.g., “plaid” … “more of the same”) (1991: 335). In effect, since we have a belief about what the blind region contains – typically, ‘more of the same’ – why should the brain go to the trouble of generating experience as well? Dennett goes on to suggest that this treatment of spatial holes can plausibly be extended to temporal holes (gaps in the continuity of experience) also. Our visual experience is constantly interrupted by our eyes darting about during saccades. We don’t notice the resulting holes or gaps in our experience, but they don’t need to be filled in because we’re not designed to notice them. More generally: ‘One of the most striking features of consciousness is its discontinuity – as revealed in the blind spot, and the saccadic gaps, to take the simplest examples. The discontinuity of consciousness is striking because of the apparent continuity of consciousness.’ (1991: 356)
Although Dennett himself concentrates on explaining why we are inclined to describe our experience as continuous if it really discontinuous, the approach can be extended to the immediate experience of change, or so Chuard argues:
Roughly … the apparent phenomenology of putative temporal experiences (i. e., putative experiences of motion, succession, duration, etc., but mere successions of experiences, really, according to the atomist) can be appropriately described as a function of (a) the successive combination of the phenomenal character of each single experience in the succession, (b) the temporal relations – distance, order, succession – between such experiences, (c) the degree of overlap between the representational contents of adjacent temporal parts in the succession, together with (d) various limitations – cognitive, mnemonic, introspective. (Chuard 2011: 17)
Suppose the ‘succession of static snapshots’ conception of experience, as proposed by the Cinematic antirealist is correct. Provided the contents and temporal arrangement of these static snapshots are enough to convince our brains that we are perceiving motion and change, we will inevitably believe that this is what we are perceiving, and hence describe our experience in such terms. Isn’t this all that we are required to explain? For Dennett and Chuard nothing further is needed.
In response realists will fully accept that we believe that change and continuity (of the Modest and/or Strong forms) are features of our immediate experience. What they are unlikely to accept is the proposal that (in effect) these features of our experience reduce to these beliefs. They will claim – and on the face of it, plausibly – that we know there is more to our consciousness than our beliefs about our consciousness. We know this because we have direct introspective access to the content and character of our experiences, and typically, our beliefs about the character of our experiences are informed by what introspection reveals. Hence if we believe our visual field is spatially continuous, it is because – when we direct our attention and introspect – we find precisely this; similarly, if we believe our immediate experience exhibits continuity and embraces change, it is because these same features are to be found in our experience. Prudent realists will accept that our judgements about the character of our experience are fallible. But they will also point that our judgements are less likely to err when they concern the more basic and ubiquitous features of our consciousness, and – arguably – change and continuity are among these features. The situation would be different if the antirealist could provide reasons for being particularly sceptical about our judgements concerning change and continuity – reasons for thinking that our beliefs about these features of our experience are more dubious than the belief that colour, sound or warmth are experienced. It is certainly possible to argue – and some antirealists have (e.g., Plumer 1985) – that we know these beliefs are false because it is impossible to provide intelligible account of how we can be directly aware of change or movement. We will be considering such arguments when we come to assess the viability of the various realist proposals.
Dennett himself is unmoved by such considerations. While recognising that we find it natural to think our beliefs about our experiences are answerable to a distinct and distinctive realm of experience, Dennett argues that this is misguided, that ultimately – so far as consciousness is concerned – there is only judgement and belief:
You seem to think there’s a difference between thinking (judging, deciding, being of the heartfelt opinion that) something seems pink to you and something really seeming pink to you. But there is no such difference. There is no such difference as really seeming – over and above the phenomenon of judging in one way or another that something is the case. (1991: 364)
Dennett’s strong reductionism with regard to experience is an extreme and controversial doctrine. It may well give antirealists what they need, but many may find the price rather too high.
5. Extensional Models
While PT-realists agree that change, persistence and other temporally extended phenomena can feature in our immediate experience, they disagree over the experiential structures which make this possible. Cinematic realists hold that all our experiences of change are the product of gap-free successions of momentary stream-phases, each possessing momentary – and static, motion-free – phenomenal contents. As we saw in §4.1, although this version of realism can seem appealing, it is also problematic, in several respects. Proponents of the remaining principal forms of realism, the Extensional and Retentional approaches, allow that the contents of our consciousness are themselves dynamic – they can contain or present succession and persistence – but they disagree about the manner in which these contents exist within consciousness. On the Retentional view, which we shall be looking at in more detail in §6, the dynamic contents are housed in episodes of consciousness that are themselves momentary. According to the Extensional view, the topic of this section, these contents are themselves spread through (or extended over) time.
5.1 The Extensional Specious Present
Although the Extensional model can be developed in different ways, much of what these variants have in common can be brought out by looking at how proponents of the approach construe individual specious presents. For present purposes, so as to bring the essentials to the fore, it will be useful to focus on a very simple instance. Figure 5 depicts a single specious present with a very simple content: ‘C’ and ‘D’ are each brief tones, which are heard and experienced in succession; this specious present contains nothing but these two tones.
Figure 5.
Both ‘C’ and ‘D’ here denote the actual ‘live’ experiencings of tones C and D, rather than memory-images or any other form of after-the-event representation. The specious present they jointly compose is a (short-ish) period of continuous experiencing, spread through ordinary time. Although D occurs later than C, it is also experienced as following on from C (as indicated by the small block-arrows connecting the two). Accordingly, what we have here is a genuine experience of succession, and no mere succession of experiences. Since the tones are experienced together, albeit in succession, the two are phenomenally unified, or diachronically co-conscious – as indicated by the lower double-headed arrow. The limits of the specious present are determined by the temporal extent of the diachronic co-consciousness relationship.
As we saw in §2.5, in characterizing his presence-time, Stern held that experiences unfolding over an interval of time can “form a unified and complex act of consciousness regardless of the non-simultaneity of individual parts.” Since the successive phases of the specious present depicted in Figure 5 do form a unified ensemble, they clearly conform to Stern’s conception of a presence-time. James sometimes referred to the specious present a duration-block, which he characterized thus: ‘We do not first feel one end and then feel the other after it, and from the perception of the succession infer an interval of time between, but we seem to feel the interval of time as a whole, with its two ends embedded in it.’ (1890: 610) The specious present of the Extensional model conforms to this characterization. Since the successive constituents which compose a duration-block are live experiences, the Extensional specious present also conforms fully to the Immediacy Thesis (see §3): change can be experienced with the same force, vivacity (or immediacy) as colour, sound or any other phenomenal feature.
Figure 6.
The specious present, thus construed, is not confined to the housing of successions of discrete tones: it can also house continuous change, in the manner shown in Figure 6. Here we see a ball falling, bouncing and rising again, all within the confines of a single specious present. The contents of specious presents are often dynamic temporal patterns of this sort – though of course real-life specious presents will usually have far complex and more varied content: in addition to perceptual contents (from all five senses) there will usually be conscious thoughts, bodily sensations, mental images and so forth.
There may seem to be a fundamental difficulty with supposing that our immediate experience extends through time in the way being envisaged. Since the successive contents contained within a specious present are experienced together, isn’t there is a sense in which both tones are present even though they are non-simultaneous? Recalling the Extensional Simultaneity Problem (from §3), this can easily seem absurd. If x and y are experienced together, and both x and y are present, how can x and y fail to be simultaneous? If x and y are both occurring now, mustn’t they also be simultaneous? It is for precisely this reason that Le Poidevin argues that change and duration cannot be directly perceived.[10] However, closer scrutiny suggests there is no real difficulty here. The earlier and later contents of a single specious present do not occupy ‘the present moment’ if this is construed as the durationless interface between past and future – the defining trait of the Extensional approach is the rejection of the confinement of consciousness to momentary stream-phases. Nonetheless, there is a sense – a quite different sense – in which all the contents of a specious present could legitimately be regarded as ‘being present’: such contents possess (what we might call) phenomenal presence, i.e., they each have the immediacy and vivacity that is characteristic of experiences as they occur. There is no contradiction in the idea that experiences (or experiential contents) at different times can possess this property, they obviously do: yesterday’s toothache was as vivid and real current toothache at the time I felt it as the toothache I am currently feeling – both have just as much phenomenal presence.[11]
Returning to our main theme – the makeup of individual specious presents – while Figures 5 and 6 capture the core features of the Extensional model, they also have their limitations: the Extensional approach can accommodate different views as to general character and composition of consciousness, and these differences do not register in these diagrams. Some philosophers hold that consciousness has an act-object (or awareness-content) structure, so every experiencing – even the simplest –involves two distinguishable components: an awareness (however construed) on the one hand, and an object or content on the other. Other philosophers reject this two-level picture, and hold that contents do not need to fall under an awareness in order to be conscious. As we shall see in §5.4, the Extensional model is compatible with both these views. Divergent conceptions of the nature of perceptual experience are also very relevant in this context. Is the moving item shown in Figure 6 a phenomenal feature of a conscious state, or is it a physical object in motion through physical space? Those who incline to the direct (or naïve) realist view of perception will favour the latter answer, whereas those who subscribe to the indirect realist (or Lockean-style representational) view of perception will favour the former answer. In slightly more general terms, Extensional theorists who believe that in our ordinary perceptual experience we are presented with purely phenomenal items (sense-data, qualia or similar) will regard the visual and auditory contents of specious presents as themselves being phenomenal in nature. Although most Extensional theorists subscribe to this general view of perception – e.g., Foster, Broad, Dainton, Sprigge – there is no obvious obstacle to combining the Extensional conception of the specious present with a direct realist construal of perception. With this combination of views, a typical specious present will consist of a temporally extended episode of awareness, some of whose contents will be internal or phenomenal (e.g., a conscious thought, a mental image), whereas others will be external (e.g., a bouncing ball, a moving car).[12]
Enough has been said – for present purposes at least – about individual specious presents. The next task is to examine how individual specious presents, construed in a broadly Extensional manner, combine to form continuous streams of consciousness. As we shall see, on this issue there are significant divergences of opinion among Extensional theorists – divergences which impact significantly on the general structure of temporal consciousness.
5.2 The Discrete Block Model
When it comes to explaining how individual specious presents combine to form streams of consciousness, a simple and perspicuous solution is available to the Extensional theorist: perhaps a stream of consciousness is nothing more than a succession of specious presents laid end-to-end in the manner of a line of building blocks, or bricks in a wall, in the manner depicted in Figure 7 below. Here just a short stretch of a stream of consciousness is depicted, consisting of just two adjacent specious presents, SP1 and SP2, but the same experiential structure could easily extend over longer periods.
Figure 7.
Something along the lines of this ‘Discrete Block’ (as we might call it) conception of a stream of consciousness has been advocated by Sprigge, Bradley and (perhaps) Whitehead.[13] But while it has a simplicity that may well be appealing, it is also problematic.
PT-realists are agreed that change and succession feature in our immediate experience. To be viable on the phenomenological level, a realist account of how this is possible must not just capture some of the change that it is plausible to suppose we directly experience, it must capture all of it. Let us suppose that C-D-E-F in Figure 7 are brief tones that are heard in succession. Given that this sequence is a typical one – with no sudden or massive disruptions in the listener’s consciousness over the relevant period – each tone will be heard as flowing into (or giving way) to its immediate successor. The discrete block model certain captures some of these experienced transitions: namely C-D (occurring in SP1) and E-F (occurring in SP2). But what of the transition between D and E? Since each of these tones occurs in a distinct specious present, and (by hypothesis) there is no specious present which includes them both, this transition is not experienced. For a sequence of contents to be experienced as a succession, they must be experienced together, and to be experienced together they need to be diachronically co-conscious. C and D are thus related, as are E and F, but D and E are not diachronically co-conscious. The tones are experienced in a sequence – D is heard first, then E – but they are not experienced as a sequence – or to put it another way, these tones form a succession of experiences, but there is no experience of succession. The difficulty is serious and pervasive: Figure 7 illustrates just one instance of a ‘missed’ succession, if the Discrete Block model obtained, every transition between successive specious presents would fail to be experienced. Evidently, this is not a desirable result, at least from the standpoint of realism.
Essentially the same point can be made in terms of the distinction drawn in §3 between the Moderate and Strong Continuity theses. If our streams of consciousness were structured in the way envisaged, there would be no gaps in our experience – no periods during which nothing is being experienced – and so the key requirement of Modest Continuity is satisfied. But the Strong Continuity Thesis requires more: as well as an absence of gaps, all the successive brief phases which make up a single stream must experientially connected to their immediate neighbours – each must be experienced as flowing into its successor. The Discrete Block model evidently falls short in this respect.
5.3 Broad’s Partial Extensionalism
A very different variant of the Extensional approach was proposed by C.D. Broad in Scientific Thought (1923). As we have already seen, Broad subscribed to the Immediacy Thesis: he held that (over short intervals) we experience change with the same phenomenal immediacy as we experience colour or sound. Since change can only be directly apprehended if our consciousness can span a temporal interval, Broad concluded that consciousness can span a temporal interval. Given this commitment, his (1923) account is naturally classed as Extensional. However, as noted in §2.7, this is not the whole story: the mechanics of Broad’s account are such that is probably more accurately construed as only partially Extensional. For Broad also held that our experience of change occurs within momentary episodes of experiencing – a doctrine which is characteristic of Retentional accounts.
This hybrid model is heavily dependent upon a particular conception of the structure of experience. Broad generally worked with a two-level ‘act-object’ or ‘awareness-content’ conception of consciousness. On this conception, any episode of experiencing comprises two components: an act of awareness, and a phenomenal content; experiences per se come into being when contents are apprehended by acts of awareness. Broad starts his analysis by proposing that acts of awareness that are themselves strictly momentary are capable of apprehending phenomenal contents distributed over short periods of time, in the manner depicted in Figure 8.
Figure 8.
The earlier and later parts of the temporal spread apprehended by the momentary act of awareness depicted in Figure 8 are evidently experienced together – they are diachronically co-conscious – and they are also experienced as a succession. This spread of content is experienced as a temporally extended whole, in conformity with James’ characterization of the specious present as a ‘duration-block’. There is however, one significant point of divergence: whereas James held that the specious present both backward and forward (or future-directed) elements, for Broad it is entirely backward-looking: it stretches from the present point of time a short distance into the past.
Whatever one may think of its reliance on a ‘momentary awareness + extended content’ mechanism, Broad’s theory has – on the face of it at least – a distinctive advantage over the Sprigge’s Discrete Block model when it comes to conforming to the Strong Continuity Thesis. The many experienced successions the Discrete Block model fails to register are all effortlessly captured by Broad’s theory. This is easily appreciated with the assistance of Figure 9.
Figure 9.
As can be seen, act of awareness A1 apprehends the tone-sequence C-D, and act of awareness A3 apprehends the tone-sequence E-F, but the tone-sequence not recognized by the Discrete Block model – D-E – is now apprehended by the act of awareness A2, which occurs between A1 and A3. Since Broad postulated that the acts of awareness form a dense continuum (hence between A1 and A2 there are uncountable number of other acts, and likewise between A2 and A3) the theory can accommodate all the experienced transitions it needs to accommodate. The act-continuum is represented in Figure 9 by the line running beneath A1-A3.
In the light of what has been said so far, it would be natural to suppose that Broad would identify individual specious presents with momentary acts and the contents these acts apprehend (e.g., the combination A1[C-D] would count as a single specious present). In fact he opted for another position. Agreeing with James that strictly durationless experiences (or apprehensions) are abstractions, Broad insists that a viable account of sensible duration must rest on the foundation of continuous periods of sensing. Since he defines the duration of the specious present in terms of momentary acts, strictly speaking temporally extended acts do not possess specious presents; however, they do possess close analogues of these: what is (in effect) the specious present of an interval of sensing S is the stretch of content that is apprehended throughout S. To get a rough idea of what this involves, consider the continuous act of sensing A1-A2 in Figure 9. What stretch of content does the specious present of this act comprise? According to Broad the answer is D. The earlier phases of A1-A2 apprehend C (or parts of it), and the later phases of it apprehend E (or parts of it), but D is the largest stretch of content that is apprehended by every phase of A1-A2.
This feature of Broad’s theory is counterintuitive, and it gives rise to some intriguing, and arguably peculiar, results.[14] Present purposes, however, will best be served by concentrating on two most fundamental problems faced by Broad’s account. The first worry concerns phenomenological adequacy. Consider again tone-phase D in Figure 9. As we have just seen, it is experienced as a whole throughout the period of sensing [A1-A2]. Broad may reject durationless acts of sensing, but he does not reject acts of sensing of varying extents or durations, and [A1-A2] includes as proper parts many acts of finite duration that are shorter than itself, and just as [A1-A2] apprehends D as a whole, so too do all these finite parts. In which case, instead of being experienced just once, won’t D be experienced many times over? How could it be otherwise, given that each of these finite parts includes an experiencing of the whole of D? If Broad’s model predicts the existence of experiences which do not actually occur, it seems safe to conclude that the mechanism at the heart of it is flawed.[15]
The second worry is whether Broad’s model can secure the continuity of consciousness in a way that is acceptable to the realist. At the heart of Broad’s account are acts of sensing which apprehend temporally extended contents. Since in the case of a continuous stream of consciousness these acts form a dense continuum, there is no difficulty with ‘gaps’ in consciousness, and so Broad’s account meets the requirements of the Modest Continuity Thesis. It is not clear, however, that it meets the requirements of the Strong Continuity Thesis. To do so, Broad’s account must allow successive phases of a stream to be experienced as flowing into one another – it must make room for experiential connections between stream-phases – but this looks problematic. Returning to Figure 9, consider the extended act of sensing stretching from A1 to AN, and the extended act stretching from shortly after AN to A2, where AN (not shown in the figure) is roughly mid-way between A1 and A2. These two extended acts can be as close together in time we like, but they are nonetheless entirely distinct acts of awareness, and the two are not experientially connected. Hence the problem. It is true that the acts apprehend (in part) the same content, but it is not clear this suffices to forge the required experiential links. We can certainly stipulate that the acts concerned have the same subject, but in the absence of any compelling story as to how this secures phenomenal continuity it is not clear how this helps either. Nor is it clear that a viable account can be constructed if we remain faithful to the spirit of Broad’s approach. Suppose we were to hold that the acts [A1-AN] and [AN-A2] are unified by virtue of their both falling under a second-order act of awareness, an act which apprehends first-order acts (and their contents). Since the entire spread of content apprehended over the interval encompassed by A1 and A2 would be experienced together, the result would be phenomenologically unrealistic: the specious present would have twice the duration that it has in actuality. And the difficulties do not end here: for what unifies the second-order acts? As illustrated in Figure 10, if we take this route, we can easily end up with a situation in which the entire content of a stream of consciousness is apprehended as a single whole, by a single all-embracing act.
Figure 10.
According to one theological tradition, God’s experience has the character of a totum simul, and takes in the entire history of the universe in a single apprehension. Since it is clear that our is experience is not of this form – the span of our immediate awareness is measured in seconds at most – it is clear that this way of securing Strong Continuity is a non-starter.
5.4 The Overlap Model
The problems encountered by the Discrete Block theory and Broad’s hybrid model point the way forward to a more promising Extensional account. Recall the problem of ‘missed transitions’ that afflicts the Discrete Block model: in the case of the succession of tones C-D-E-F, although C and D are experienced as phenomenally continuous, E and F likewise, D and E are not – for unlike [C-D] and [E-F] they do not fall within the confines of a single specious present (see Figure 7). There is a simple remedy for this problem: the omitted transition can be restored by positing that [D-E] itself forms a single specious present – a further ‘duration block’ in the manner of Sprigge and Bradley – which for convenience we can call SPX. Since (by hypothesis) D-E is an experienced succession, this stipulation is well-motivated on the phenomenological level. What is more, this useful result has been achieved without recourse to Broad’s momentary-act/extended content conception of the specious present: the account remains fully (rather than merely partially) Extensionalist.
As Figure 11 makes clear, acknowledging the existence of SPX does not commit us to recognizing any experiences in addition to C-D-E-F, for SPX is composed of the second-half of SP1 (= D) and the first-half of SP2 (= E). To put it another way, there is a D-type experience to be found in SP1 and also in SPX, but there are not two token D-type experiences, for the simple reason that the D-token in SP1 is numerically identical with the D-token in SPX, and similarly for E. By holding that specious presents can overlap by sharing common parts, phenomenal continuity can be secured in an economical manner. As Foster puts it: ‘where the successive patterns overlap, the experiences which present them overlap in a corresponding way’ (1991: 249).
Figure 11.
Recognizing the existence of SPX may not incur the cost of additional experiences, but it does involve the introduction of additional experiential relationships. It is now being supposed that D and E are connected by the relationship of diachronic co-consciousness, whereas previously it was previously held that only C-D and E-F were so related. But on the assumption that D and E constitute a directly experienced succession, D evidently is diachronically co-conscious with E.
As this example also illustrates, the relationship of diachronic co-consciousness is not transitive: C and D are related in this manner, as are D and E, but C and E are not so related. This failure of transitivity plays a crucial role in ensuring that the overlap theory delivers a phenomenologically realistic result. If diachronic co-consciousness were transitive, all the phases of a continuous stream of consciousness would be experienced together – we would be back with the totum simul. The point concerning transitivity failure was perhaps first noted by Russell in his ‘On the Experience of Time’ (1913), where he assumes specious presents combine by overlap to form streams of consciousness.[16] The Overlap Model (as we can call it) in the form just outlined has been advocated on several occasions by Foster (1979; ;1982: 255ff; 1991: 247–50) and Dainton (2000/6: §7; 2003; 2009).
Its proponents intend the Overlap Model to capture not just the structure of a sequences of tones, but of entire streams of consciousness. If the Overlap theorists are right, such streams are composed of successions of stream-phases which overlap by sharing common parts, in the manner of C-D-E-F. However, on close scrutiny the description just given of the structure of even this simple sequence turns out to be inadequate. By supposing that SPX exists, in addition to SP1 and SP2 we capture an experienced transition (or specious present) which actually exists, but which gets ignored by the Discrete Block model. But does Figure 11 include all the experienced transitions which exist in the case of C-D-E-F? Given the continuous character of our experience, probably not: for just as D-E is experienced as an extended whole, so to is the tone-pattern running from the mid-point in C to the mid-point in E, or from the three-quarter point in D to the three-quarter point in F, and so on for many (many) other cases. These ‘omitted transitions’ are easily accommodated by the Overlap Model, as illustrated in Figure 12. This new example is still unrealistically simplistic, for once again only a single sensory modality is represented, in the form of a visual experience of a bouncing ball, but it in one key respect it is less artificial.
Figure 12.
As this diagram makes illustrates, specious presents can be more closely packed than sequence of tones depicted in Figure 11. In this new example, each double-headed line represents a distinct specious present, each differing from its immediate neighbours by a just-noticeable difference.[17] Although these specious presents overlap to a very significant degree, given that the overlap takes the form of a sharing of common parts, there is no phenomenologically unrealistic repetitions: the greater the extent to which two specious presents overlap, the greater the number of phases they share. What we have here is what is needed: a temporally extended stretch of consciousness that is phenomenally continuous, and which includes all the experienced transitions which are experienced. Or so the Overlap theorists maintain.