Aquinas and Descartes 73argued that there is no conflict between reason and faith. Phi
losophy, he contended, is based on reason, and reason can
support faith. Aquinas accepted on faith that God exists, but he
formulated proofs of His existence to support that belief. Aquinas ’
five proofs for the existence of God are rational explanations of
an article of faith.
There are two main concepts in Aquinas’ moral doctrines: the
Aristotelean ideas of eudaemonism, i.e., happiness as a result of
the activity of the soul (reason) in pursuit of virtue, and teleol
ogy, i.e., that everything has a purpose and naturally moves
toward the fulfillment of that purpose. Aquinas agrees with
Aristotle that happiness is the proper end of human action and
that it is natural that men seek happiness, since the will cannot
help but desire it. Thus men should act, with their free will, to
achieve happiness, and their actions can be determined to be
good or bad depending on how their freely willed acts conform
to the end desired. The critical question for Aquinas was to
determine what constitutes the ultimate happiness.
Ultimate happiness must include God, so Aquinas outlines a
path for man to follow on the road to God. First Aquinas
describes the relation between our appetites and desires and the
human intellect. Intelligence is the essence of man, a gift from
God, the divine spark within us. In all cases our intellect must
have primacy over our appetites and desires. Man also has free
will. While the intellect tells us what we ought or ought not to do,
it is the will which causes us to act. Thus, when we act in
accordance with reason we act well, when we act against reason
we act poorly. Man’s greatest good is to act in accordance with
reason. Whatever is contrary to reason is considered evil.
A self-evident axiom is, “One should do good and avoid evil.”
The person who lives according to this axiom is virtuous. Virtue,
then, according to Aquinas, is the permanent disposition to act
in conformity with reason. He who acts in conformity with
reason is intellectually virtuous. Since man has free will and
since all men are also imperfect, man must be morally virtuous
as well as intellectually virtuous. Moral virtues consist of those
personal habits and qualities which control the appetites and
desires, such as temperance and fortitude. The intellectual vir
tues, knowledge, wisdom, and prudence, inform the will of the
right path to take toward virtue. If man were perfect, he would