From his Sacred History:
Moses is, in the Hebrew religious history, the man who revealed the name of God. In the encounter of the burning bush, he had exclaimed, “Behold, when I come unto the children of Israel, and shall say unto them, The God of your fathers hath sent me unto you; and they shall say to me, What is his name? what shall I say unto them?” (Exod. III:13). And, bold as the question was, God did not conceal the answer. The importance of the event is not easily understood by the modern mind, but in antiquity men attributed a mysterious power to the name, an irresistible potency. We retain certain traces of this belief; we feel very strongly that a name describes a character; we speak of a Don Juan, or a Tartuffe; Balzac chose with great care the sounds that should designate his characters; and in the “Our Father” we still praise the name of God which, as the Commandment says, is not to be taken in vain.
In Mesopotamia and in Egypt the knowledge of a name was regarded as sacred. The ancient Greek philosophers even admitted that there is a connection between things and their names. To name is to call into existence. To know the name of a god is to have the power to invoke him. In the Egyptian legend of Isis we see the god Ra, stung by a serpent, begging the goddess-magician to cure him; and she first of all demands that he should give his name, the secret of his supreme power. Something that our society, desiccated by rationalism, refuses to understand is regarded in the ancient traditions as one of the spiritual foundations of humanity…
And God said unto Moses, I am that I am: and he said, Thus shalt thou say unto the children of Israel, I am…The LORD God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath sent me unto you: this is my name for ever, and this is my memorial unto all generations. (Exodus III:14-15) In speaking of himself, God says, I am. When man speaks of Him, he must say, “He is.” The latter is to be the name of God as we find it throughout the Bible….
What is the meaning of that enigmatic formula, I am that I am? Countless pages have been written on the subject of those simple words. The study of grammar permits of two interpretations. Jahweh could signify “it is”–which expresses the metaphysical idea of the uncreated being, which exists in itself which requires no thing and no person in order to be: the God of eternity. Or it can mean, “it makes to be,” “it realises,” that which creates, sustains, keeps promises, God the creator. The two interpretations are in fact linked and the tradition of Israel does not separate them.
At all events, the Bible clearly indicates that the knowledge of the divine name marks an advance. “I am Jahweh,” God further said to Moses. “I appeared unto Abraham, unto Isaac, and unto Jacob, by the name of El-Shaddai, but by my name of Jahweh was I not known to them.” (Exodus VI:3) El-Shaddai was the God of power, the mysterious and incalculable power by which everything on earth is regulated. It is the Most High, the Almighty. Jahweh is something more, the same God, the God of the Patriarchs, but defined..
It would be out of place to carry metaphysical analysis too far. Moses’ contemporaries probably had only a vague intuition of the immense varieties that were implied. But what is clearly important is the development that in the course of generations grew from it and which is implicit in the sacred tetragram. God is unique in His very nature, and not by the exclusive choice of a man or a nation, which differentiates him absolutely from Hammurabi’s Marduk, or the Egyptian Aton. He is necessarily the God of the Universe, of the whole of humanity, even if He is know and served by a specific nation. And the virtues which in Him are worshipped–bounty, justice, and benevolence–are the natural attributes of His unique being, since every injustice, every violence, is opposed to harmony and unity…
Here again, we are struck by the human character of this theology. Its point of departure is an even in history. Israel, unlike so many nations, does not claim any legendary descent from God; the revelation took place at a moment of time and was transmitted through a man. Hebraic humanism which is, together with that of Athens and Rome, one of the three foundations of our civilisation, depends entirely upon this simple affirmation.