with it at all. Rather, all created things are merely causes whose effects cannot occur without an additional cause. To suppose, however, that we know of an existing cause that necessitates by its very essence—a complete cause independently producing its effect—would run contrary to how things actually exist. No effect arises except through the combined operation of two or more causes; even then, the effect may fail to result from them.

If this applies to everything said to produce an effect, whether through its choice and power or through its nature and force, then none of these things independently produces its effect, let alone necessitates it by its very essence. Nor is an effect that arises when causes come together necessary: for example, burning when fire encounters a body, or illumination when the sun faces a body. These conditions may be present without either illumination or burning occurring.

If, then, nothing in existence produces an effect by itself, let alone necessitates it, and an effect arises only from two things—as a child arises from its parents and a conclusion from its two premises—and yet