I begin with the humblest and most widely diffused of loves, the love in which our experience seems to differ least from that of the animals.... The Greeks called this love storge (two syllables and the g is ‘hard’). I shall here call it simply Affection. My Greek Lexicon defines storge as ‘affection, especially of parents to offspring’; but also of offspring to parents. And that, I have no doubt, is the original form of the thing as well as the central meaning of the word. The image we must start with is that of a mother nursing a baby, a bitch or a cat with a basketful of puppies or kittens; all in a squeaking, nuzzling heap together; purrings, lickings, baby-talk, milk, warmth, the smell of young life. The importance of this image is that it presents us at the very outset with a certain paradox. The Need and Need-love of the young is obvious; so is the Gift-love of the mother. She gives birth, gives suck, gives protection. On the other hand, she must give birth or die. She must give suck or suffer. That way, her Affection too is a Need-love. There is the paradox. It is a Need-love but what it needs is to give. It is a Gift-love but it needs to be needed. We shall have to return to this point.
C.S. Lewis, The Four Loves (1960; HarperCollins: 2002) 39-40.