The Complete Aristotle (eng.)

the subject.
Thus, ‘man’ is predicated of the individual man; but ‘animal’ is
predicated of ‘man’; it will, therefore, be predicable of the
individual man also: for the individual man is both ‘man’ and
‘animal’.
    If genera are different and co-ordinate, their differentiae are
themselves different in kind. Take as an instance the genus
‘animal’ and the genus ‘knowledge’. ‘With feet’, ‘two-footed’,
‘winged’, ‘aquatic’, are differentiae of ‘animal’; the species of
knowledge are not distinguished by the same differentiae. One
species of knowledge does not differ from another in being
‘two-footed’.
    But where one genus is subordinate to another, there is nothing
to prevent their having the same differentiae: for the greater
class is predicated of the lesser, so that all the differentiae of
the predicate will be differentiae also of the subject.
4
    Expressions which are in no way composite signify substance,
quantity, quality, relation, place, time, position, state, action,
or affection. To sketch my meaning roughly, examples of substance
are ‘man’ or ‘the horse’, of quantity, such terms as ‘two cubits
long’ or ‘three cubits long’, of quality, such attributes as
‘white’, ‘grammatical’. ‘Double’, ‘half’, ‘greater’, fall under the
category of relation; ‘in a the market place’, ‘in the Lyceum’,
under that of place; ‘yesterday’, ‘last year’, under that of time.
‘Lying’, ‘sitting’, are terms indicating position, ‘shod’, ‘armed’,
state; ‘to lance’, ‘to cauterize’, action; ‘to be lanced’, ‘to be
cauterized’, affection.
    No one of these terms, in and by itself, involves an
affirmation; it is by the combination of such terms that positive
or negative statements arise. For every assertion must, as is
admitted, be either true or false, whereas expressions which are
not in any way composite such as ‘man’, ‘white’, ‘runs’, ‘wins’,
cannot be either true or false.
5
    Substance, in the truest and primary and most definite sense of
the word, is that which is neither predicable of a subject nor
present in a subject; for instance, the individual man or horse.
But in a secondary sense those things are called substances within
which, as species, the primary substances are included; also those
which, as genera, include the species. For instance, the individual
man is included in the species ‘man’, and the genus to which the
species belongs is ‘animal’; these, therefore-that is to say, the
species ‘man’ and the genus ‘animal,-are termed secondary
substances.
    It is plain from what has been said that both the name and the
definition of the predicate must be predicable of the subject. For
instance, ‘man’ is predicted of the individual man. Now in this
case the name of the species man’ is applied to the individual, for
we use the term ‘man’ in describing the individual; and the
definition of ‘man’ will also be predicated of the individual man,
for the individual man is both man and animal. Thus, both the name
and the definition of the species are predicable of the
individual.
    With regard, on the other hand, to those things which are
present in a subject, it is generally the case that neither their
name nor their definition is predicable of that in which they are
present. Though, however, the definition is never predicable, there
is nothing in certain cases to prevent the name being used. For
instance, ‘white’ being present in a body is predicated of that in
which it is present, for a body is called white: the definition,
however, of the colour white’ is never predicable of the body.
    Everything except primary substances is either predicable of a
primary substance or present in a primary substance. This becomes
evident by reference to particular instances which occur. ‘Animal’
is predicated of the species ‘man’, therefore of the individual
man, for if there were no individual man of whom it could be
predicated, it could not be predicated of the species ‘man’ at all.
Again, colour is present in body, therefore in individual bodies,
for if there were no individual body in which it was present, it
could not be present in body at all. Thus everything except primary
substances is either predicated of primary substances, or is
present in them, and if these last did not exist, it would be
impossible for anything else to exist.
    Of secondary substances, the