This is part five of the discussion attempting to prove agency, the idea that beings can generate thoughts and actions when there were none previously. Before we get to the refutation of the circular argument, we will go ahead and complete the argument for agency.
As we said earlier, potency must be actualized by something which is already in act. Thus the effect preexists in the cause (preexists in act) or the potential could not be actualized. Thus God, as pure act, has all possible effects preexisting in Him. He can cause all possible things because He is not limted by potency. Therefore God is capable of actualizing all possible potency, since the power to actualize already exists in Him. Note that since all possible effects preexist in pure act, the potency is not actualized “from nothing” but from the already-existing power that exists in a being of pure act.
Further, since God has all capability of actualizing all possible potency, He can actualize potency in humans. Indeed, since we know we exist, and we know we have potency, we know we are beings combined of act and potency. Thus humans can actualize potency according to the act provided us by the pure act, God. This is merely saying that God has the power to give to humans the ability to actualize potency. God, as being able to cause all things, caused humans to be able to be secondary causes, such as walking, talking, and thinking. Note again that this ability of humans to actualize potency is not something coming from nothing, but is act moving potency to actual. Humans are actual, therefore they have the power to actualize potency, at least to the extent that they are limited by potency and type of act.
At this point in the argument, we can conclude that we could have started our support of agency from merely observing humans, who we know exist and have potential. By these two facts alone, we can know that humans have some act, and are therefore capable of actualizing some potential.
With this, we have effectively demonstrated that agents exist and can generate acts.
Next we will get around to refuting the arguments against agency.