To contribute to what has already been said it is necessary to know of what we are speaking. When confronted with some notion about something that is perceived we ask a few fundamental questions:
- Is it? If this question is affirmed then we ask:
- What is it?
The first question is concerning the fundamental existence of a thing. (does it ‘be’ or not)
The second question is about the essence of the existent thing.
When it comes to God we can know that he exists however we can never know fully the divine essence. This is not peculiar to God. We cannot know any essences in a complete way. This is the reason why Thomas answers the second question by saying:
Deus sit ipsum esse subsistens
Probably the best contemporary english translation of this because of the use of ‘sit’ instead of ‘est’ is: ‘If we can say anything about God then he is that which is to be subsisting.’ Though even this is almost to declarative a statement.
One of the problems is that since we are contingent rational beings the way our own minds work is that we proceed from that which is seen to that which is unseen - from senses knowledge to non-sense knowledge (so to speak). But, since God is completely immaterial we have no direct sense knowledge of him. However, the way we know material creatures is by first discerning their existence and then speaking about the way in which it exists. This is because for all contingent beings their existence is prior to their essence in our way of coming to know them. However, God is not a contingent being nor is he, for Thomas, a being (as such). Rather, even attributing being to God, for Thomas, is not fully correct. This is the general critique of the commentators. They constantly get the “analogy of being” wrong because they make God a being - though a super-emminent being. This is more akin to the thought of Bonaventure and Scotus. This is also, I believe, where we get the notion that ‘God is the fullness of being’ which is a helpful statement but not a correct statement about God according to Thomas’ thinking. No place in the corpus of his work does he call God ‘being,’ ‘a being,’ ‘the being,’ ‘the fullness of being,’ etc.
So, effectively what is being said about God is that while we distinguish between his essence and his existence so that we, as contingent beings, can speak about him; we must assert that there is no division in God and thus it is his very essence to exist as the originator and cause of all that exists.
Put simply in God there is no essence, properly speaking; rather God simply exists.