1. Nor is the existence of God necessarily self-evident as soon as the meaning of the name 'God' is known. First, because it is not evident, even to all who admit the existence of God, that God is something greater than which nothing can be conceived, since many of the ancients said that this world was God. Then granting that universal usage understands by the name 'God' something greater than which nothing can be conceived, it will not follow that there exists in rerum natura something greater than which nothing can be conceived. For 'thing' and "notion implied in the name of the thing" must answer to one another. From the conception in the mind of what is declared by this name 'God' it does not follow that God exists otherwise than in the mind. Hence there will be no necessity either of that something, greater than which nothing can be conceived, existing otherwise than in the mind; and from this it does not follow that there is anything in rerum natura greater than which nothing can be conceived. And so the supposition of the nonexistence of God goes untouched. For the possibility of our thought outrunning the greatness of any given object, whether of the actual or of the ideal order, has nothing in it to vex the soul of any one except of him alone who already grants the existence in rerum natura of something than which nothing can be conceived greater.*
2. Nor is it necessary for something greater than God to be conceivable, if His non-existence is conceivable. For the possibility of conceiving Him not to exist does not arise from the imperfection or uncertainty of His Being, since His Being is of itself most manifest, but from the infirmity of our understanding, which cannot discern Him as He is of Himself, but only by the effects which He produces; and so it is brought by reasoning to the knowledge of Him.
3. As it is self-evident to us that the whole is greater than its part, so the existence of God is most self-evident to them that see the divine essence, inasmuch as His essence is His existence. But because we cannot see His essence, we are brought to the knowledge of His existence, not by what He is in Himself but by the effects which He works.*
4. Man knows God naturally as he desires Him naturally. Now man desires Him naturally inasmuch as he naturally desires happiness, which is a certain likeness to the divine goodness. Thus it is not necessary that God, considered in Himself, should be naturally known to man, but a certain likeness of God. Hence man must be led to a knowledge of God through the likenesses of Him that are found in the effects which He works.
5. God is that wherein all things are known, not as though other things could not be known without His being known first, as happens in the case of self-evident principles, but because through His influence all knowledge is caused in us.