Ethics, part 1 | Page 6

a reason or cause must be granted for its existence; if,
on the contrary, it does not exist, a cause must also be granted, which
prevents it from existing, or annuls its existence. This reason or cause
must either be contained in the nature of the thing in question, or be
external to it. For instance, the reason for the non-existence of a square

circle is indicated in its nature, namely, because it would involve a
contradiction. On the other hand, the existence of substance follows
also solely from its nature, inasmuch as its nature involves existence.
(See Prop. vii.)
But the reason for the existence of a triangle or a circle does not follow
from the nature of those figures, but from the order of universal nature
in extension. From the latter it must follow, either that a triangle
necessarily exists, or that it is impossible that it should exist. So much
is self-evident. It follows therefrom that a thing necessarily exists, if no
cause or reason be granted which prevents its existence.
If, then, no cause or reason can be given, which prevents the existence
of God, or which destroys his existence, we must certainly conclude
that he necessarily does exist. If such a reason or cause should be given,
it must either be drawn from the very nature of God, or be external to
him--that is, drawn from another substance of another nature. For if it
were of the same nature, God, by that very fact, would be admitted to
exist. But substance of another nature could have nothing in common
with God (by Prop. ii.), and therefore would be unable either to cause
or to destroy his existence.
As, then, a reason or cause which would annul the divine existence
cannot be drawn from anything external to the divine nature, such
cause must perforce, if God does not exist, be drawn from God's own
nature, which would involve a contradiction. To make such an
affirmation about a being absolutely infinite and supremely perfect is
absurd; therefore, neither in the nature of God, nor externally to his
nature, can a cause or reason be assigned which would annul his
existence. Therefore, God necessarily exists. Q.E.D.
>>>>>Another proof--The potentiality of non-existence is a negation
of power, and contrariwise the potentiality of existence is a power, as is
obvious. If, then, that which necessarily exists is nothing but finite
beings, such finite beings are more powerful than a being absolutely
infinite, which is obviously absurd; therefore, either nothing exists, or
else a being absolutely infinite necessarily exists also. Now we exist
either in ourselves, or in something else which necessarily exists (see
Ax. i. and Prop. vii.). Therefore a being absolutely infinite--in other
words, God (Def. vi.)--necessarily exists. Q.E.D.
*****Note--In this last proof, I have purposely shown God's existence

'a posteriori,' so that the proof might be more easily followed, not
because, from the same premises, God's existence does not follow 'a
priori.' For, as the potentiality of existence is a power, it follows that, in
proportion as reality increases in the nature of a thing, so also will it
increase its strength for existence. Therefore a being absolutely infinite,
such as God, has from himself an absolutely infinite power of existence,
and hence he does absolutely exist. Perhaps there will be many who
will be unable to see the force of this proof, inasmuch as they are
accustomed only to consider those things which flow from external
causes. Of such things, they see that those which quickly come to
pass--that is, quickly come into existence--quickly also disappear;
whereas they regard as more difficult of accomplishment --that is, not
so easily brought into existence--those things which they conceive as
more complicated.
However, to do away with this misconception, I need not here show the
measure of truth in the proverb, "What comes quickly, goes quickly,"
nor discuss whether, from the point of view of universal nature, all
things are equally easy, or otherwise: I need only remark that I am not
here speaking of things, which come to pass through causes external to
themselves, but only of substances which (by Prop. vi.) cannot be
produced by any external cause. Things which are produced by external
causes, whether they consist of many parts or few, owe whatsoever
perfection or reality they possess solely to the efficacy of their external
cause; wherefore the existence of substance must arise solely from its
own nature, which is nothing else but its essence. Thus, the perfection
of a thing does not annul its existence, but, on the contrary, asserts it.
Imperfection, on the other hand, does annul it; therefore we cannot be
more certain of the existence of anything, than of the existence of a
being absolutely infinite or perfect--that is, of God. For inasmuch as