Abstract: Some philosophers characterize ‘speciesism’ as a violation of the principle of moral equality, which requires us to give equal consideration to the similar interests of all individuals in our moral reasoning. Speciesism is claimed to be a prejudice on a par with racism or sexism. Two important examples of speciesism are a willingness to support institutions that inflict massive amounts of suffering on animals raised for food, in order to satisfy our gastronomic preferences for eating meat, and a willingness to perform experiments on animals that inflict suffering, which we would not allow to be inflicted on human beings. This paper examines and rejects the principle of equality that is at the heart of claims that speciesism is wrong. The more general aim is to call attention to two different conceptions of the foundations of morality and moral thinking.