As the Philosopher states, the opinion of Socrates was that knowledge can never be overcome by passion, wherefore he held every virtue to be a kind of knowledge and every sin a kind of ignorance. In this he was somewhat right because, since the object of the will is a good or an apparent good, it is never moved to an evil unless that which is not good appear good in some respect to the reason, so that the will would never tend to evil unless there were some ignorance or error in the reason. . . . Experience, however, shows that many act contrary to the knowledge that they have, and this is confirmed by divine authority, according to the words of Luke 12:47: The servant who knew the will of his lord . . . and did not do it . . . and James 4:17: To him . . . who knoweth to do good and doeth it not, to him it is a sin. . . .
. . . [N]othing prevents a thing which is known habitually from not being considered actually, so that it is possible for a man to have correct knowledge . . . and yet not to consider his knowledge actually; and in such a case it does not seem difficult for a man to act counter to what he does not actually consider . . . in so far as passions hinder him from considering it. How it hinders him in three ways. First, by way of distraction. . . . Secondly, by way of opposition, because a passion often inclines to something contrary to what man knows in general. Thirdly, by way of bodily transmutation (biological process), the result of which is that reason is somewhat fettered so as not to exercise its act freely, even as sleep or drunkenness, on account of some change wrought on the body, fetters the use of reason. That this takes place in the passions is evident from the fact that sometimes, when the passions are very intense, man loses the use of reason altogether; for many have gone out of their minds through excess of love or anger (I-II,77,2). Socrates rightly identified intellectual knowledge as a necessary cause of moral evil, as St. Thomas points out in the first paragraph above; for the will cannot move to any end unless the intellect first portrays this end as good. Thus we always choose an apparent good, an end that appears to us to be good. All evil consists in wrongly identifying what is in fact an evil as a good, e.g., seeing some sin as pleasant. This is why it is so important to keep our minds pure and right. But Socrates confused this necessary cause with a sufficient cause, and taught that all evil was caused only by ignorance. As St. Thomas points out in the second paragraph, experience and divine revelation both contradict this. Socrates was too much the rationalist to let experience judge his theory rather than vice versa. The explanation for the experienced fact that we do indeed do what we know to be evil is that our knowledge is not merely a cause of our willing, it is also an ef ect of our willing. Influenced by our passions, we can command our mind to look or not to look at something. St. Thomas also sees an ambiguity in “knowing”: we may habitually, unconsciously know that a thing is evil—not only morally forbidden but also harmful to ourselves—and yet not allow this knowledge to rise up into consciousness to deter us from the evil because we are so in love with the false pleasure that we attach to the evil. Our passions are disordered. Drug addiction is a clear example. All sin is addictive, like a drug: it blinds the mind and rational will. All sin harms the sinner: it gouges out his eyes. In extreme cases, “many have gone out of their minds” through disordered passion; but all sin does this in some degree. It has to, for it if didn’t, we could not sin. Socrates is right about that. St. Thomas also points out, very realistically, that addiction to sin often has a physical, bodily dimension. Almost everything about us is psychosomatic.
