iculty whether they
may not rather be regarded as being in the Third Category, that of
Quality ([Greek: to poion]). When we say, "This is a man," do we not
declare what sort of a thing he is? do we not declare his Quality? If
Aristotle had gone farther along this line, he would have arrived
at the modern point of view that a man is a man in virtue of his
possessing certain attributes, that general names are applied in
virtue of their connotation. This would have been to make the line
of distinction between the First Category and the Third pass between
First Essence and Second, ranking the Second Essences with Qualities.
But Aristotle did not get out of the difficulty in this way. He solved
it by falling back on the differences in common speech. "Man" does not
signify the quality simply, as "whiteness" does. "Whiteness" signifies
nothing but the quality. That is to say, there is no separate name in
common speech for the common attributes of man. His further obscure
remark that general names "define quality round essence" [Greek: peri
ousian], inasmuch as they signify what sort a certain essence is, and
that genera make this definition more widely than species, bore fruit
in the mediaeval discussions between Realists and Nominalists by which
the signification of general names was cleared up.

Another difficulty about the mutual exclusiveness of the Categories
was started by Aristotle in connexion with the Fourth Category,
Relation ([Greek: pros ti] _Ad aliquid_, _To something_). Mill remarks
that "that could not be a very comprehensive view of the nature of
Relation which would exclude action, passivity, and local situation
from that Category," and many commentators, from Simplicius down to
Hamilton, have remarked that all the last six Categories might be
included under Relation. This is so far correct that the word Relation
is one of the vaguest and most extensive of words; but the criticism
ignores the strictness with which Aristotle confined himself in
his Categories to the forms of common speech. It is clear from
his examples that in his Fourth Category he was thinking only of
"relation" as definitely expressed in common speech. In his meaning,
any word is a relative which is joined with another in a sentence by
means of a preposition or a case-inflection. Thus "disposition" is a
relative: it is the disposition _of_ something. This kind of relation
is perfect when the related terms reciprocate grammatically; thus
"ma