The Basic Works of Aristotle (Modern Library Classics) by Richard Mckeon

something else
that is meant. Similarly, the expression ‘double’ has this external reference, for it is the double
of something else
that is meant. [6b] So it is with everything else of this kind. There are, moreover, other relatives, e. g. habit, disposition, perception, knowledge, and attitude. The significance of all these is explained by a reference to something else and in no other way. Thus, a habit is a habit
of
something,
(5) knowledge is knowledge
of something,
attitude is the attitude
of something.
So it is with all other relatives that have been mentioned. Those terms, then, are called relative, the nature of which is explained by reference to something else, the preposition ‘of’ or some other preposition being used to indicate the relation. Thus, one mountain is called great
in comparison with another;
for the mountain claims this attribute
by comparison with
something. (10) Again, that which is called similar must be similar to
something else,
and all other such attributes have this external reference. It is to be noted that lying and standing and sitting are particular attitudes, but attitude is itself a relative term. To lie, to stand, to be seated, are not themselves attitudes, but take their name from the aforesaid attitudes.
    It is possible for relatives to have contraries. (15) Thus virtue has a contrary, vice, these both being relatives; knowledge, too, has a contrary, ignorance. But this is not the mark of all relatives; ‘double’ and ‘triple’ have no contrary, nor indeed has any such term.
    It also appears that relatives can admit of variation of degree. (20) For ‘like’ and ‘unlike’, ‘equal’ and ‘unequal’, have the modifications ‘more’ and ‘less’ applied to them, and each of these is relative in character: for the terms ‘like’ and ‘unequal’ bear a reference to something external. Yet, again, it is not every relative term that admits of variation of degree. (25) No term such as ‘double’ admits of this modification. All relatives have correlatives: by the term ‘slave’ we mean the slave
of a master;
by the term ‘master’, the master
of a
slave;
by ‘double’, (30) the double
of its half;
by ‘half’, the half
of its double;
by ‘greater’, greater
than that which is less;
by ‘less’, less
than that which is greater.
    So it is with every other relative term; but the case we use to express the correlation differs in some instances. Thus, by knowledge we mean knowledge
of
the knowable; by the knowable, that which is to be apprehended
by
knowledge; by perception, (35) perception
of
the perceptible; by the perceptible, that which is apprehended
by
perception.
    Sometimes, however, reciprocity of correlation does not appear to exist. This comes about when a blunder is made, and that to which the relative is related is not accurately stated. If a man states that a wing is necessarily relative to a bird, the connexion between these two will not be reciprocal, for it will not be possible to say that a bird is a bird by reason of its wings. The reason is that the original statement was inaccurate, for the wing is not said to be relative to the bird
qua
bird, since many creatures besides birds have wings, but
qua
winged creature. [7a] If, then, the statement is made accurate, the connexion will be reciprocal, for we can speak of a wing having reference necessarily to a winged creature, and of a winged creature as being such because of its wings.
    Occasionally, perhaps, it is necessary to coin words, (5) if no word exists by which a correlation can adequately be explained. If we define a rudder as necessarily having reference to a boat, our definition will not be appropriate, for the rudder does not have this reference to a boat
qua
boat, as there are boats which have no rudders. (10) Thus we cannot use the terms reciprocally, for the word ‘boat’ cannot be said to find its explanation in the word ‘rudder’. As there is no existing word, our