How is it possible to love some particular person for herself, or for himself, alone? Love—especially erotic love—does not typically begin when we love someone ‘for herself alone’. It very often begins with some strikingly superficial feature or property of the beloved: a certain grace of movement, maybe, or a glimpse inside a young man's shirt (Plato, Charmides 155d4), or the colour of Anne Gregory's hair in Yeats's poem. As Yeats sardonically points out, it is quite common for love never to get any further than this. It's hardly news that plenty of love affairs have rested on no deeper foundations than hair coloration.

The same point applies, though perhaps less dramatically and with less obvious potential for disaster, to the non-erotic varieties of love. Maybe I hang out with you because you shake a wicked cocktail, or can teach me how to catch rainbow trout. Maybe, in fact, this is the only reason I hang out with you. Non-sexual friendships of these superficial sorts—and perhaps I can show that there is some philosophical interest in that word ‘superficial’—are as familiar and commonplace as sexual friendships of the sort that bothered Anne Gregory.