In his book The Omnivore’s Dilemma, Michael Pollan discusses why Jeremy Bentham, the great nineteenth-century English philosopher, and Peter Singer, a prominent philosopher of the late twentieth century, questioned the practice of eating animals.
On page 308 of the first hardcover edition of Pollan’s book, Pollan notes that Singer quotes Bentham when trying to explain his own thinking on this matter. Bentham had wondered why animals should not have the same rights as humans. If we try to argue that they should lack those rights because they cannot reason as humans can, then (Bentham asks), should we argue that a human infant should have fewer rights than an adult horse or dog, since an adult horse or dog can reason better than a baby can? Similarly, a full-grown dog or horse can communicate more effectively than a baby can; does this mean that adult dogs and horses should have more rights than human babies?
Bentham argues, instead, that the reason animals deserve rights is simply because they can suffer. The more an animal can suffer pain, the more (according to this argument) it deserves rights that approximate the rights of humans.
Interestingly, Pollan later notes that Bentham did in fact justify eating meat. Pollan reports that in
a passage seldom quoted by animal rightists Bentham defended meat eating on the grounds that “we are the better for it, and they [the animals] are never the worse. . . . The death they suffer in our hands commonly is, and always may be, a speedier and, by that means a less painful one, than that which would await them in the inevitable course of nature.” (p. 328)
Pollan immediately notes, however, that the suffering inflicted on animals in modern industrial farming is enormous and is far worse than anything most of them would encounter during most of their lives in nature. Pollan, then, succeeds in raising very serious questions and in making us aware that satisfying answers to such questions are also often very difficult to come by.