ion is not a
reality, but only an idea. But this is plainly seen to be false from
the very fact that things themselves have a mutual natural order and
habitude. Nevertheless it is necessary to know that since relation has
two extremes, it happens in three ways that a relation is real or
logical. Sometimes from both extremes it is an idea only, as when
mutual order or habitude can only go between things in the
apprehension of reason; as when we say a thing "the same as itself."
For reason apprehending one thing twice regards it as two; thus it
apprehends a certain habitude of a thing to itself. And the same
applies to relations between _being_ and _non-being_ formed by reason,
apprehending _non-being_ as an extreme. The same is true of relations
that follow upon an act of reason, as genus and species, and the like.

Now there are other relations which are realities as regards both
extremes, as when for instance a habitude exists between two things
according to some reality that belongs to both; as is clear of all
relations, consequent upon quantity; as great and small, double and
half, and the like; for quantity exists in both extremes: and the same
applies to relations consequent upon action and passion, as motive
power and the movable thing, father and son, and the like.

Again, sometimes a relation in one extreme may be a reality, while in
the other extreme it is an idea only; and this happens whenever two
extremes are not of one order; as sense and science refer respectively
to sensible things and to intellectual things; which, inasmuch as they
are realities existing in nature, are outside the order of sensible
and intellectual existence. Therefore in science and in sense a real
relation exists, because they are ordered either to the knowledge or
to the sensible perception of things; whereas the things looked at in
themselves are outside this order, and hence in them there is no real
relation to science and sense, but only in idea, inasmuch as the
intellect apprehends them as terms of the relations of science and
sense. Hence the Philosopher says (Metaph. v) that they are called
relative, not forasmuch as they are related to other things, but as
others are related to them. Likewise for instance, "on the right" is
not applied to a column, unless it stands as regards an animal on the
right side; which relation is not really in the column, but in the
animal.

Since therefore God is outside the whole order of creation