…the absence of an agent, and at other times to the presence of an impediment. In neither of these two ways, then, can such privative evils be attributed to God.
As for the first—ascribing them to the lack of an agent—this is impossible, for He is the Manifest Truth; one cannot say that they failed to exist because their doer or their requisite cause was lacking.
As for the second—that their non-existence is due to the presence of a hindrance—such a hindrance is needed only when the causal factor already exists. Had He willed to bring them about, nothing could have prevented Him, for He does whatever He wills. Yet God may create both the cause and the hindrance: if He renders the cause complete, nothing can stop it; if He does not render it complete, the hindrance prevails because the cause is weak and lacks God’s assistance.
Thus, nothing fails to exist except because He did not will it, just as nothing exists except because He wills it. These privative misdeeds are therefore ascribed to the servant—sometimes because the servant lacks the requisite cause, and at other times because a hindrance arises from within him.
The first case, the absence of a cause, is obvious: in and of himself the servant possesses no power, no strength, no good, and no primary cause of good. Were any such thing truly his, it would count as a cause; since it is not, the cause is lacking and the deed is ascribed to him on account of that lack. Indeed, some actions do issue from him by God’s aid, and he counts as their secondary cause; whatever fails to issue from him is due to the absence of that cause.
As for the presence of a contrary hindrance, this is because the soul may become constricted and weak, unable to combine actions that are possible in themselves yet mutually inconsistent for him. If his hearing or sight becomes preoccupied with something, or his speech, or his contemplation and will, or if his limbs are engaged in many tasks, they become diverted from performing other acts.