the relation of that which is 1.5 times
something else to that something is a definite numerical relation to a
number; and that which is (n+1)/n times something else is in an
indefinite relation to a number, just as "the many times as great" is
in an indefinite relation to 1.The relation of that which exceeds to that
which is exceeded is numerically quite indefinite, for number is
commensurate, and is not predicated of the incommensurate; whereas
that which exceeds, in relation to that which is exceeded, is "so
much" plus something more; and this something more is indefinite, for
it is indifferently equal or not equal to the "so much."Thus not only are all these
things said to be relative in respect of number, but also the "equal"
and "like" and "same," though in another way: for all these terms are
used in respect of "one". Things are "the same" whose essence is one;
"like" whose quality is one; "equal" whose quantity is one. Now "one"
is the starting-point and standard of number; and so all these
relations involve number, though not all in the same way.
(b) Active and passive things are called relative in virtue of an
active or passive potentiality or actualization of the potentialities;
e.g., that which can heat is called relative to that which can be
heated, because it can heat; and again the thing heating is called
relative to the thing heated, and the thing cutting to the thing cut,
because their potentialities are actualized. Numerical relations, on
the other hand, are not actualized
(except as has been described elsewhere)1
have no actualizations in respect of motion.Of things potentially relative, some are
further relative in respect of particular times; as, e.g., that which
has made or will make is relative to that which has been or will be
made. It is in this way that a father is called father of a son; the
one has acted, and the other has been acted upon, in a particular way.
Again, some things are relative in virtue of a privation of their
potentiality; such is "the impossible" and all similar terms, e.g.
Thus relative terms which involve
number and potentiality are all relative because their very essence
contains a reference to something else; but not because something else
is related to their essence. But (c) that which is measurable or
knowable or thinkable is called relative because something else is
related to its essence.For "thinkable" signifies that there is a thought which thinks it;
but thought is not relative to that of which it is the thought (for
then the same thing would have been said twice). And similarly sight
is the sight of something; not of that of which it is the sight,
although this is of course true—it is relative to some color
or other similar thing.To describe it in the other way—"the sight of the object
of sight"—would be to say the same thing twice.