are known as soon as the terms are known, which the Philosopher (1
Poster. iii) says is true of the first principles of demonstration.
Thus, when the nature of a whole and of a part is known, it is at once
recognized that every whole is greater than its part. But as soon as
the signification of the word "God" is understood, it is at once seen
that God exists. For by this word is signified that thing than which
nothing greater can be conceived. But that which exists actually and
mentally is greater than that which exists only mentally. Therefore,
since as soon as the word "God" is understood it exists mentally, it
also follows that it exists actually. Therefore the proposition "God
exists" is self-evident.

Obj. 3: Further, the existence of truth is self-evident. For
whoever denies the existence of truth grants that truth does not
exist: and, if truth does not exist, then the proposition "Truth does
not exist" is true: and if there is anything true, there must be
truth. But God is truth itself: "I am the way, the truth, and the
life" (John 14:6) Therefore "God exists" is self-evident.

_On the contrary,_ No one can mentally admit the opposite of what is
self-evident; as the Philosopher (Metaph. iv, lect. vi) states
concerning the first principles of demonstration. But the opposite of
the proposition "God is" can be mentally admitted: "The fool said in
his heart, There is no God" (Ps. 52:1). Therefore, that God exists is
not self-evident.

_I answer that,_ A thing can be self-evident in either of two ways: on
the one hand, self-evident in itself, though not to us; on the other,
self-evident in itself, and to us. A proposition is self-evident
because the predicate is included in the essence of the subject, as