Summary of the de ente argument for God

I. Everything that belongs to an individual is either caused by a principle belonging to its essence or comes to it from a principle outside of it.

II. In things that have a distinction between essence and existence, the act of existence cannot come from a principle of the essence. That is because the essence would be the cause of a thing’s existence, which would imply that the essence exists before it exists, which is a contradiction.

III. So if a thing’s essence is distinct from its existence, its existence must come from outside of that thing.

IV. When one thing depends on another for existence, that dependence is structured as an essentially ordered causal series, and so the cause must exist simultaneously with the effect.

V. Therefore, there must be some first cause of existence.

VI. This first cause of existence cannot have an essence distinct from its existence, otherwise it would depend on something else outside of itself for its existence.

VII. Therefore, the first cause of existence must be pure existence.

VIII. As was noted in the second stage of this argument, there can only be one thing that is identical with its existence.

IX. This thing that is identical with its existence is what we call God.