It is often forgotten that the creation of the universe is not a truth of a philosophical order, but rather an article of faith.
Ancient philosophy knows nothing of creation in the absolute sense of the word.
The Faith presupposes the existence of God, and nothing existing outside of God. Yet creation does mean the production of an entirely new subject out of nothing. So we might say that by creation God makes room of something which is wholly outside of Himself. The creature has no ontological foundation either in itself being created from nothing, nor in the divine essence, for in the act of creation God was under no necessity of any kind whatever. Creation is a free act of His Will, and this free act is the sole foundation of the existence of all beings.