For as a hedonist, Bentham apparently bases moral status not on the dignity of rational nature but rather solely on the capacity to feel pleasure and pain. And this is clearly different from the Kantian position. Yet I claim that Bentham’s idea here is in general terms not inconsistent with Kantian ethics but is instead a corollary of the Kantian position. I would even claim that Kantian ethics provides a better justification for it than Bentham’s hedonism–a shallow empiricist doctrine that cannot account properly even for the values it assigns to pleasure and pain in human beings.
[…] Nonhuman animals do not have the capacity to reason or to talk. Therefore, beyond making the obvious point that they are not persons in the strict sense, whether they have or lack these capacities is irrelevant to how we should treat them. Bentham is therefore correct in telling us not to ask about these matters when we are deciding how to treat animals. What is relevant, because it relates their capacities to those of rational nature, is the fact that they can suffer, and desire, and sometimes also care – about members of their own species, or even occasionally about members of other species, such as humans. Bentham is therefore also correct in telling us what we should ask about these capacities, for they are the relevant ones. Bentham is correct, however, not because Kant is wrong, but because Kant is right.
Jeremy Bentham