value. For how shall it vary? Because the _quantity_ of producing
labor varies? But _that_ is the very principle which he is writing
to overthrow. Shall it vary, then, because the _value_ of the
producing labor varies? But _that_ is impossible on the system of
Mr. Malthus; for, according to this system, the value of labor is
invariable.

_Phil_. Stop! I've thought of a dodge. The thing shall vary
because the _quantity_ of labor commanded shall vary.

_X_. But how shall _that_ vary? A can never command a greater
quantity of labor, or of anything which is presumed to be of invariable
value, until A itself be of a higher value. To command an altered
quantity of labor, which (_on any theory_) must be the _consequence_
of altered value, can never be the _cause_ of altered value. No
alterations of labor, therefore, whether as to quantity or value,
shall ever account for the altered value of A; for, according to Mr.
Malthus, they are either insufficient on the one hand, or impossible
on the other.

_Phil_. Grant this, yet value may still vary; for suppose labor to
be invariable, still profits may vary.

_X_. So that, if A rise, it will irresistibly argue profits to
have risen?

_Phil_. It will; because no other element _can_ have risen.

_X_. But now column eight assigns the value of a uniform quantity
of corn--namely, one hundred quarters. In case Alpha, one hundred
quarters are worth 8.33. What are one hundred quarters worth in the
case Iota?

_Phil_. They are worth ten.

_X_. And _that_ is clearly more. Now, if A have risen, by
your own admission I am entitled to infer that profits have risen: but
what are profits in the case Iota?

_Phil_. By column four they are twenty per cent.

_X_. And what in the case Alpha?

_Phil_. By column four, twenty-five per cent.

_X_. Then profits have fallen in the case Iota, but, because
_L_ has risen in case Iota from 8.33 to ten, it is an irresistible
inference, on your theory, that profits ought to have risen.

_Phæd. (Laughing)_. Philebus, this is a sharp practice; go on, X.,
and skirmish with him a little more in this voltigeur style.

N.B.--With respect to "The Templars' Dialogues," it may possibly be
complained, that this paper is in some measure a fragment. My answer
is, that, although fragmentary in relation to the entire _system_
of Ricardo, and that previous _system_ which he opposed, it is no
fragment in relation to the radical _principle_ concerned in those
systems. The conflicting systems are brought under review simply at the
_locus_ of collision: just as the reader may have seen the
chemical theory of Dr. Priestley, and the counter-theory of his anti-
phlogistic opponents, stated within the limits of a single page. If the
principle relied on by either party can be shown to lead into
inextricable self-contradiction, _that_ is enough. So much is
accomplished in that case as was proposed from the beginning--namely,
not to exhaust the _positive_ elements of this system or that, but
simply to settle the central logic of their several polemics; to
settle, in fact, not the matter of what is evolved, but simply the
principle of evolution.