appetite moves and is moved. Therefore the intellect is not moved
by the will.

Obj. 3: Further, we can will nothing but what we understand. If,
therefore, in order to understand, the will moves by willing to
understand, that act of the will must be preceded by another act of
the intellect, and this act of the intellect by another act of the
will, and so on indefinitely, which is impossible. Therefore the will
does not move the intellect.

_On the contrary,_ Damascene says (De Fide Orth. ii, 26): "It is in
our power to learn an art or not, as we list." But a thing is in our
power by the will, and we learn art by the intellect. Therefore the
will moves the intellect.

_I answer that,_ A thing is said to move in two ways: First, as an
end; for instance, when we say that the end moves the agent. In this
way the intellect moves the will, because the good understood is the
object of the will, and moves it as an end. Secondly, a thing is said
to move as an agent, as what alters moves what is altered, and what
impels moves what is impelled. In this way the will moves the
intellect and all the powers of the soul, as Anselm says (Eadmer, De
Similitudinibus). The reason is, because wherever we have order among
a number of active powers, that power which regards the universal end
moves the powers which regard particular ends. And we may observe
this both in nature and in things politic. For the heaven, which aims
at the universal preservation of things subject to generation and
corruption, moves all inferior bodies, each of which aims at the
preservation of its own species or of the individual. The king also,
who aims at the common good of the whole kingdom, by his rule moves
all the governors of cities, each of whom rules over his own
particular city. Now the object of the will is good and the end in
general, and each power is directed to some suitable good proper to
it, as sight is directed to the perception of color, and the
intellect to the knowledge of truth. Therefore the will as agent
moves all the powers of the soul to their respective acts, except the
natural powers of the vegetative part, which are not subject to our
will.

Reply Obj. 1: The intellect may be considered in two ways: as
apprehensive of universal being and truth, and as a thing and a
particular power having a determinate act. In like manner also the
will may be considered in two ways: according to the common nature of
its object--that is to say, as ap