The prevalent view in animal ethics is that speciesism is wrong: we should weigh the interests of humans and non-humans equally. Shelly Kagan has recently questioned this claim, defending speciesism against Peter Singer’s seminal argument based on the principle of equal consideration of interests. This critique is most charitably construed as a dilemma. The principle of equal consideration can be interpreted in either of two ways. While it faces counterexamples on the first reading, it makes Singer’s argument question-begging on the (...) second. In response, Singer has grasped the first horn of this dilemma and tried to accommodate Kagan’s apparent counterexamples. In my opinion, this attempt is unpersuasive: the principle of equal consideration is inconsistent with common-sense intuitions on Kagan’s cases. Worse, Singer’s argument begs the question anyway. It therefore faces two serious objections. This is not to say that there is nothing wrong with speciesism, however. In the second half of the paper, I propose another, better argument against speciesism, which I argue is immune to both objections. According to this other argument, speciesism is wrong because it involves discriminating on the basis of a merely biological property. (shrink)