Derrida talked about his cat as a way of talking about the difference between animals and human beings. But it also came up in a discussion he had with John Milbank about the perennial question: 'Who is my neighbour?' Derrida argues both that perfect justice is impossible and also that we ought to aim for it anyway. We are always falling short. Milbank suggests that the problem with this is that there's no way of choosing between the competing demands on us. "Nothing has more weight than anything else." Why should I feed this cat when there are thousands of starving cats all over the world with no one to feed them? For Milbank, traditional Christian theology gives us permission to treat some cats as more important than others. It's not just that it's ok to feed one cat and not the others; we're morally obliged to feed our cat above other cats. Those who are closer to us have a greater demand on us than those who are further away. The idea that I'm responsible for every cat assumes that I live in a society which has broken down, where if I don't look after the cat, no one will. And who wants an ethics based on social breakdown?
Derrida responds: it's not that nothing has more weight than anything else, it's that no one has more weight than anything else. Of course we feed our cat and not all the other cats. Of course we prefer our cat to the cat next door; of course I prefer my family to others. But our preferences should worry us. If everybody only looked after those who were closest to us, "it would be the ruin of ethics". I can't feed every cat, but I shouldn't have a good conscience about all the other cats who have no one to feed them.
Which cat is my neighbour? If I had to pick, I'd go with Derrida (though I'm also struggling with the question: What Would Žižek Think?). You?