reason. Like St. Augustine he says: "I believe in order to understand"
(well persuaded that if I never believed I should never understand), and he
adds what had been in the thought of St. Augustine: "I understand in order
to believe." St. Anselm proved the existence of God by the most abstract
arguments. For example, "It is necessary to have a cause, one or multiple;
one is God; multiple, it can be derived from one single cause, and that one
cause is God; it can be a particular cause in each thing caused; but then
it is necessary to suppose a personal force which must itself have a cause
and thus we work back to a common cause, that is to say to a single one."

He proved God again by the proof which has remained famous under the name
of the argument of St. Anselm: To conceive God is to prove that He is; the
conception of God is proof of His existence; for every idea has its object;
above all, an idea which has infinity for object takes for granted the
existence of infinity; for all being finite here below, what would give the
idea of infinity to the human mind? Therefore, if the human brain has the
idea of infinity it is because of the existence of infinity. The argument
is perhaps open to difference of opinion, but as proof of a singular vigour
of mind on the part of its author, it is indisputable.

Highly intellectual also is his explanation of the necessity of
redemption. _Cur Deus Homo?_ (the title of one of his works) asked
St. Anselm. Because sin in relation to an infinite God is an infinite
crime. Man, finite and limited in capacity, could therefore never expiate
it. Then what could God do to avenge His honour and to have satisfaction
rendered to Him? He could only make Himself man without ceasing to be God,
in order that as man He should offer to God a reparation to which as God He
would give the character of infinitude. It was therefore absolutely
necessary that at a given moment man should become God, which could only be
done upon the condition that God made Himself man.