I’ve been working on a book on sexual ethics, and along the way I’ve been thinking about the question why sex is valuable, that is, why sex is something worth valuing. It’s not an uncommon view that sex is of limited value: It feels good, and pleasure is certainly good, but that’s about it; sex is not something that should really be central to people’s lives; it’s a mistake to make it so. I disagree. I wouldn’t argue that anyone has to care about sex, any more than anyone has to care about music, or architecture, or travel. But I do think that there is a way of approaching sex that shows that it can be worth valuing in the same way that one might value music or travel. I have always thought there was something not quite right about simply describing some people as `having a high sex drive’, and this is in part an initial attempt to explain why. Having a strong interest in sex is not the same as `having a high sex drive’ any more than having a strong interest in theatre is `having a strong theatre drive’.