Background knowledge:
The Screwtape Letters is a satire written by C.S. Lewis.
Quote is an excerpt from a letter from SCREWTAPE, assistant to the devil, to his nephew WORMWOOD a demon in charge of influencing a "patient"(a human) and damning its soul.
starting from page 107-108:
You will find, if you look carefully into any human's heart, that he is haunted by at least two imaginary women--a terresteraial and an infernal Venus, and that his desires differ qualitatively according to its object. There is one type for which his desire is such as to be naturally amenable to the Enemy[God]--readily mixed with charity, readily obedient to marriage, coloured all through with that golden light of reverence and naturalness which we detest; there is another type which he desires brutally, and desires to desire brutally, a type best used to draw him away from marriage altogether but which, even within marriage, he would tend to treat as a slave, an idol, or an accomplice. His love for the first might involve what the Enemy calls evil, but only accidentally; the man would wish that she was not someone else's wife and be sorry that he could not love her lawfully. But in the second type, the felt evil is what he wants; it is that 'tang' in the flavour which he is after. In the face, it is the visible animality, or sulkiness, or craft, or cruelty which he likes, and in the body, something quite different from what he ordinarily calls Beauty, something he may even, in a sane hour, describ as ugliness, but which, by our art, can be made to play on the raw nerver of his private obsession.
