How Unclean Spirits Rule over the Possessed

What you describe as happening with the demon-possessed does not contradict what we have said: that those possessed by unclean spirits say and do what they do not want to, and are forced to utter what they know nothing of. For it is perfectly clear that they are not all subject to the entry of the spirits in the same way. Some are affected in such a way that they have not the slightest idea of what they do and say; others know it and remember it afterward. But we must not imagine that this happens by the spirit pouring itself in, so that it penetrates the very substance of the soul and, united with it as it were and somehow clothed in it, speaks words and sayings through the mouth of the sufferer. We ought not to believe that they can possibly do this. For we can clearly see that this comes not from any loss in the soul but from weakness of the body. The unclean spirit seizes on those members in which the vigor of the soul resides, lays on them an enormous and unbearable weight, overwhelms the soul with the foulest darkness, and hinders its powers of understanding. We see this happen sometimes from wine too, or from fever or extreme cold, and from other illnesses that affect people from outside. This is what the devil was forbidden to try to inflict on the blessed Job, though he had received power over his flesh, when the Lord commanded him, saying, “See, I give him into your hands; only preserve his soul.” That is: do not weaken the seat of his soul and make him mad, and do not overpower the understanding and wisdom of what remains by smothering the ruling power in his heart under your weight. [a]