Basil: Contra Eunomius 1.13

The one who gave us an account of creation taught us only this much: In the beginning God made the heavens and the earth; now the earth was invisible and without form (Gen 1.1-2). Thinking it sufficient to state that who made the earth and set it in order, he has refused to waste his time investigating what the earth’s substance is, on the grounds that such an endeavour is pointless and useless to its audience. Hence, if knowledge of the earth’s substance is established neither by the testimony derived from sense-perception nor by the teaching derived from the rational account, on what basis do they still claim to possess comprehension of it? Insofar as the earth is perceptible to the senses, it is either colour or mass or lightness or heaviness or density or rarity or hardness or softness or coldness or hotness, or qualities pertaining to flavour, or shape or magnitude—none of which they can say is its substance, not even if they were to affirm all of them readily. Yet none of the wise and blessed has provided a rational account which has made it possible to consider the earth’s substance. Therefore what mode of knowledge still remains? Let them answer us, seeing that they despise all things under their feet, transcend the heaven and all the supercosmic powers, and join themselves to the first substance itself through their intellect. But it seems that self-conceit is the most difficult of all the passion in human beings since in actual fact it envelops those whom it affects in the condemnation of the devil. Hence those who have no understanding of the nature of the earth on which they trample go so far as to brag that they have penetrated the very substance of God of the universe!

God said that he was the God of Abraham and the God of Isaac and the God of Jacob, for this is my everlasting name and my memorial to the generations of generations (Ex. 3.15). When he said this, he was placing a high value on being named the God of such men due to their perfection in all virtue, considering being thus named as something proper and fitting to his majesty. Yet God did not even disclose his name to the saints, namely to Abraham and to Isaac and to Jacob, and much less did he reveal what his substance is! For he said: I am the Lord, and I appeared to Abraham and Isaac and Jacob, as I am their God, and I not disclose my name to them (Ex. 6.2-3). Clearly, he said this because his name is too great for human ears. Yet it seems that to Eunomius God has manifested not only his name, but also his very substance! This great secret, which was not manifested to any of the saints, he makes public by writing it in his books, and blurts it out to all people recklessly. While the promised blessing stored up for us are beyond human knowledge, and the peace of God surpasses intelligence (Phil. 4.7), he does not admit that the very substance of God is beyond all intelligence and beyond all human knowledge.