It's not that there are no differences between human and non-human animals, any more than there are no differences between black people and white people, freeborn citizens and slaves, men and women, Jews and gentiles, gays or heterosexuals. The question is rather: are they morally relevant differences? This matters because morally catastrophic consequences can ensue when we latch on to a real but morally irrelevant difference between sentient beings.
~ David Pearce
