Non-human animals are as a matter of routine used as means to human ends. They are killed for food, employed for labour or sport, and experimented on in the pursuit of human health, knowledge, comfort and beauty. Lip-service is paid to the obligation to cause no unnecessary suffering, but human necessity is interpreted so generously that this is a negligible constraint. The dominant traditions of Western thought, religious and secular, have provided legitimation of the low or non-existent moral status of beasts. The rival tradition, which includes the Neo-Platonists, Plutarch and Montaigne, is eccentric and archaic. But the teleologies and hierarchies of orthodoxy are equally incredible now and owe their greater respectability and influence to the inertia of custom. Disregard for beasts is supported partly by the vestigial and unowned belief that they are intended for our use, partly by a more recent piece of lore which is not only thought to be compatible with, but is sometimes held to be integral to, an enlightened scientific outlook, namely that beasts are mere complex stimulus—response mechanisms. The latter is a vexatious obstacle to progress but despite that the state of scientific and philosophical knowledge is now enormously more propitious for a re-appraisal of the moral status of beasts. Two moral philosophers, Peter Singer and Stephen Clark, have recently published books in which such a re-appraisal is attempted. Here I try to compare and assess some of the main features of their very different approaches.