d in individuals. Plato's mistake was in
confusing the mere 'this,' which is the conceived starting-point of any
sensation, but which, like a mathematical point, has nothing which can
be said about it, with individual objects as they exist and are known
in all the manifold and, in fact, infinite relations of reality. The
bare subject 'this' presents at the one extreme the same emptiness, the
same mere possibility of knowledge, which is presented at the other by
the bare predicate 'is.' But Plato, having an objection to the former,
as representing to him the merely physical and therefore the passing
and unreal, clothes it for the nonce in the various attributes which
are ordinarily associated with it when we say, 'this man,' 'this
horse,' only to strip them off successively as data of sensation, and
so at last get, by an illusory process of {183} abstraction and
generalisation, to the ultimate generality of being, which is the mere
'is' of bare predication converted into a supposed eternal substance.

Aristotle was as convinced as Plato that there must be some fixed and
immovable object or reality corresponding to true and certain
knowledge, but with his scientific instincts he was not content to have
it left in a condition of emptiness, attractive enough to the more
emotional and imaginative Plato. And hence we have elsewhere quite as
strong and definite statements as those quoted above about universals
[316] (p. 180), to the effect that existence is in the fullest and most
real sense to be predicated of _individual_ things, and that only in a
secondary sense can existence be predicated of universals, in virtue of
their being found in individual things. Moreover, among universals the
_species_, he maintains, has more of existence in it than the genus,
because it is nearer to the individual or primary existence. For if
you predicate of an individual thing of what species it is, you supply
a statement more full of information and more closely connected with
the thing than if you predicate to what genus it belongs; for example,
if asked, "What is this?" and you answer, "A man," you give more
information than if you say, "A living creature."

How did Aristotle reconcile these two points of {184} view, the one, in
which he conceives thought as starting from first causes, the most
universal objects of knowledge, and descending to particulars; the
other, in which thought starts from the individual objects, and
predicate