Chapter 3
Whenever one thing is predicated of another as of a subject, all things said of what is
predicated will be said of the subject also. For example, man is predicated of the individual man,
and animal of man; so animal will be predicated of the individual man also—for the individual man
is both a man and an animal.
The differentiae of genera which are different and not subordinate one to the other are
themselves different in kind. For example, animal and knowledge: footed, winged, aquatic, two-footed, are differentiae of animal, but none of these is a differentia of knowledge; one sort of
knowledge does not differ from another by being two-footed. However, there is nothing to prevent
genera subordinate one to the other from having the same differentiae. For the higher are predicated
of the genera below them, so that all differentiae of the predicated genus will be differentiae of the
subject also.
Chapter 4
Of things said without any combination, each signifies either substance or quantity or
qualification or a relative or where or when or being-in-a-position or having or doing or being affected. To give a rough idea, examples of substance are man, horse; of quantity: four-foot, five-foot; of qualification: white, grammatical; of a relative: double, half, larger; of where: in the
Lyceum, in the market-place; of when: yesterday, last-year; of being-in-a-position: is-lying, is sitting; of having: has-shoes-on, has-armor-on; of doing: cutting, burning; of being-affected:
being cut, being burned.
None of the above is said just by itself in any affirmation, but by the combination of
these with one another an affirmation is produced. For every affirmation, it seems, is either true or
false; but of things said without any combination none is either true or false (e.g. man, white, runs,
wins).