Peter Singer on Utilitarianism and Vegetarianism

There are three ways in which a utilitarian condemnation of the treatment of farm animals might fall short of entailing that we should switch to a vegetarian diet. Firstly, if the objection is not to all raising and killing of animals for food, but only to particular methods of raising and killing them, it would seem that we can avoid the necessity of vegetarianism by restricting our diet to the flesh of animals not reared or killed by methods involving suffering. Secondly, one might argue that, bad as factory farming is, the consequences of abolishing it are not clearly better than the consequences of continuing it. And thirdly, those who admit that it would be better if factory farming were abolished may deny that there is any utilitarian connection between this conclusion and the obligation to avoid consuming the products of factory farms.

(Peter Singer, “Utilitarianism and Vegetarianism,” Philosophy & Public Affairs 9 [summer 1980]: 325-37, at 331)