Erich Fromm. The art of love (№ 418364)

A mother's love for a growing child, love that wants nothing for itself, is perhaps the most difficult form of love attainable, and the most deceiving because of the ease with which a mother can love her baby. But precisely because it is difficult, a woman can become a truly loving mother only if she can love at all; if she is able to love her husband, other children, strangers, all people. A woman who is unable to love in this sense may be an affectionate mother while the child is small, but she cannot be a loving mother whose job it is to be ready to endure the separation of the child - and even after separation continue to love him.