The reading about love continues. This is from Chapter 8 of Freud’s Group Psychology and the Analysis of the Ego (1922):
The tendencies whose trend is towards directly sexual satisfaction may now be pushed back entirely, as regularly happens, for instance, with the young man’s sentimental passion; the ego becomes more and more unassuming and modest, and the object more and more sublime and precious, until at last it gets possession of the entire self-love of the ego, whose self-sacrifice thus follows as a natural consequence. The object has, so to speak, consumed the ego. Traits of humility, of the limitation of narcissism, and of self-injury occur in every case of being in love; in the extreme case they are only intensified, and as a result of the withdrawal of the sensual claims they remain in solitary supremacy.
This happens especially easily with love that is unhappy and cannot be satisfied; for in spite of everything each sexual satisfaction always involves a reduction in sexual over-estimation. Contemporaneously with this ‘devotion’ of the ego to the object, which is no longer to be distinguished from a sublimated devotion to an abstract idea, the functions allotted to the ego ideal entirely cease to operate. The criticism exercised by that faculty is silent; everything that the object does and asks for is right and blameless. Conscience has no application to anything that is done for the sake of the object; in the blindness of love remorselessness is carried to the pitch of crime. The whole situation can be completely summarised in a formula: The object has taken the place of the ego ideal.