Atheists make a great fuss about how God does not exist. This claim, they think, is at odds with what those who believe in God hold. But is it? What kind of God do the atheists have in mind? And can someone who believes in God not actually feel happy to say that God does not exist?

Ordinarily, of course, we think that something either exists or does not exist. So we say that the Eiffel Tower exists while the Colossus of Rhodes does not. And if, like some, we presume that belief in God is a scientific hypothesis, or that God is a top, invisible person, a celestial consciousness (with or without a beard) living alongside the Universe in time while learning about it from on high, then, presumably, He, too, either exists or does not exist, just like you and I. But there are other, and more traditional, ways of thinking about God.

Take, for example, what we find in the writings of St Thomas Aquinas. He never thought of God as an entity seriously comparable to what we find in the Universe. He took God to be the cause of everything real and imaginable to us, the cause of all natural kinds and their members, the reason why there is something rather than nothing. Aquinas, of course, realised that when we talk of God we are forced to make use of words we have come up with to name and describe what we find in the world in which we live. And since he took people to be higher forms of being than anything else around us, he naturally ascribed to God what we most value in ourselves — such as intelligence. But Aquinas was equally keen to emphasise that God is not a creature, not a member of the world, not a being among beings, not, in this sense, an existing thing. God, he says, “is to be thought of as existing outside the realm of existents, as a cause from which pours forth everything that exists in all its variant forms”. For Aquinas, there is a serious sense in which it is true to assert that God does not exist. He would readily have agreed with Kierkegaard’s statement: “God does not exist, he is eternal.”

Or we can put it another way. There is a sense in which Aquinas holds that only God really exists. Creatures are there, right enough, but, for Aquinas, their being is derived or dependent. All that they are and do is God’s work in them. They have no reality from themselves. Creatures are temporal, finite, and caused to exist, while God is none of these things. Aquinas puts all this by saying that God’s existing does not differ from his substance, that God, and only God, exists by nature, that God is “subsistent being” while everything else “has” being — has it as given to it. You can find a similar line of thinking coming from St Anselm of Canterbury. God, he declares, is “the being who exists in a strict and absolute sense” since with Him there is nothing temporal and nothing received.

Traditionally speaking, therefore, it makes sense to say both that God does not exist and that only God exists, which means we should be careful when it comes to what we mean when we declare ourselves atheists or not. And there is surely a further sense in which all Jews, Muslims, and Christians can be thought of as atheists. For they do not believe there are any gods. They believe there is a Creator of all things visible and invisible, not that there is a class of gods to which the Creator belongs. The first of the Ten Commandments tells us to have no gods. It effectively tells us to be atheists, to stop being interested in extremely powerful creatures and to focus instead on the unfathomable mystery behind and within the world that we can, to some extent, fathom. God the maker of all things cannot be a part of what He brings forth. He belongs to no category. He is not a god. There are no gods.

Brian Davies is an English Dominican. He is Professor of Philosophy at Fordham University, New York