§ 178
Any conflict in her psyche is between the erotic and the egoistic-social impulses. The only inhibitions against the erotic impulses, as everywhere, appear to be the egoistic-social ones, though it has been pointed out that even the erotic instinct itself contains an innate antithesis that might cause a conflict even were the egoistic-social influences minimized or even removed.
One suspects that in the woman these unconscious doubts must come primarily from not having been completely controlled, so completely in the erotic sphere that no egoistic-social impulses are for the time perceptible. A woman of a highly refined nature whose husband’s erotic control is not forceful enough thus to expunge totally all egoistic-social impulses for the time being, will have a certain number of them not disposed of.
It thus happens that such a married woman, when loved by another than her husband and yielding to him, will in so doing obliterate even this residue of egoistic-social inhibitions. This explains why an illicit love is to them so powerful a stimulus. They observe a sudden separation of the two spheres of impulse in themselves, and they realize the illimitable enhancement of the erotic motive over the egoistic-social, the latter naturally appearing as dross against the gold of the erotic. If in the clandestine love they have swept away all egoistic-social conventions, they have practically rendered themselves subject to erotic impulses alone. Thus the very fact of this love being illicit appears to render it purely erotic, absolute, all-comprehensive, the conflict settled beforehand.