(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.