to the
elements, he has them in their very substance, yet in such a way that
the higher elements, fire and air, predominate in him by their power;
for life is mostly found where there is heat, which is from fire; and
where there is humor, which is of the air. But the inferior elements
abound in man by their substance; otherwise the mingling of elements
would not be evenly balanced, unless the inferior elements, which
have the less power, predominated in quantity. Therefore the body of
man is said to have been formed from the slime of the earth; because
earth and water mingled are called slime, and for this reason man is
called "a little world," because all creatures of the world are in a
way to be found in him.

Reply Obj. 1: The power of the Divine Creator was manifested in man's
body when its matter was produced by creation. But it was fitting
that the human body should be made of the four elements, that man
might have something in common with the inferior bodies, as being
something between spiritual and corporeal substances.

Reply Obj. 2: Although the heavenly body is in itself nobler than the
earthly body, yet for the acts of the rational soul the heavenly body
is less adapted. For the rational soul receives the knowledge of
truth in a certain way through the senses, the organs of which cannot
be formed of a heavenly body which is impassible. Nor is it true that
something of the fifth essence enters materially into the composition
of the human body, as some say, who suppose that the soul is united
to the body by means of light. For, first of all, what they say is
false--that light is a body. Secondly, it is impossible for something
to be taken from the fifth essence, or from a heavenly body, and to
be mingled with the elements, since a heavenly body is impassible;
wherefore it does not enter into the composition of mixed bodies,
except as in the effects of its power.

Reply Obj. 3: If fire and air, whose action is of greater power,
predominated also in quantity in the human body, they would entirely
draw the rest into themselves, and there would be no equality in the
mingling, such as is required in the composition of man, for the
sense of touch, which is the foundation of the other senses. For the
organ of any particular sense must not actually have the contraries
of which that sense has the perception, but only potentially; either
in such a way that it is entirely void of the whole genus of such
contraries--