Appeared in Fall 1993, Vol. XIX, No. 2,3 Download PDF here

The question of the demonstration of the existence of God has occupied the thoughts and arguments of many Thomists. All agree that the existence of God can be demonstrated in philosophy. The disagreement turns around the origin of the demonstration. This involves a further argument about the origin of the common understanding of the term “God.” St. Thomas clearly states that God’s existence must be demonstrated from his effects.1The name of God cannot be defined because His essence and existence are one. As the created intellect cannot comprehend his existence, so it cannot comprehend his essence so as to define it. Since God’s essence cannot be comprehended by a created intellect, he cannot be reduced to a genus. As he cannot be reduced to a genus, he cannot be defined. So to be an object of demonstration or question, there must be some other explanation of the name or term given to God by men than one which would be capable of definition. The signification of the name God and its origin is here taken as the middle term in a demonstration and the explanation of the name cannot be a definition. It must therefore be derived from the effects of God and be a quia not a propter quid demonstration.

There are many opinions about the origin of this name. For some it is derived from revelation; for others from an examination of the Metaphysics of being without any reference to Natural Philosophy; for others from the act of judgement; for other from the things in themselves which we experience; for others from the desire of intellectual beings to know God. In this paper, I want to examine the exact manner in which men become aware of God and then how this could be an object of question in a science. There are some who think that the question of the origin of the name for God must be radically distinguished from the question of his existence. While it is true that the problems are not exactly the same, they do overlap. When Aristotle calls God the First Cause and the Unmoved Mover, does he mean a being which cannot be reduced to a genus for definition or a being in whom essence and existence are one, even though he may not exactly use these terms.

I shall now list the various positions usually invoked as authentic interpretations of St. Thomas. Each has much value to it. In this little article, I have given a few minor problems with these positions to show that there is need for further clarification. I in no sense mean these problems to be an exhaustive criticism of the positions involved. The explanation I hope to give in the body of this article should explain the various problems with each position in a clearer light.

A. The Meaning of the Notion of God
must come from Revelation

This is the position of the Gilson school. The main effect of God is esse as manifested in the name God gives to himself on Sinai, ego sum qui sum.2But to demonstrate this requires anĀ appreciation of the real distinction between essence and existence, which involves a correction of certain ideas of Aristotle.

Such a knowledge can only come from the notion of God found in revelation and specifically from the ego sum qui sum (Yahweh). As a result, though God’s existence can be demonstrated by reason, it can only be demonstrated by those philosophers who are aware of the authentic notion of God which is contained in the Holy Scriptures. These are the Christian philosophers and those who know about Judaeo-Christian revelation. Plato and Aristotle did not come to the notion of being as being. They only examined particular being and so they could not have a fully developed Metaphysics. Since the demonstration of God in Metaphysics demands a concept of being as being, which includes immaterial being, they could not know about him.3

One small problem with this position is that it is based on the assumption that the only authentic name of God is one fromĀ revelation like ego sum qui sum. This is because it is the one which most properly expresses the notion of subsistent esse. St. Thomas says many times that the names which philosophers give to God are from his effects and these effects are the sensible effects. In fact, the names in the Bible are even derived from things which are known to us by the senses.4