PETER Singer, once a Greens candidate and now our most famous philosopher, has changed his mind on killing babies. Good news, you might think, since this author of Animal Liberation used to say parents had a right to kill imperfect children in their first month of life. But in fact he's now told World magazine it would be ethically fine to kill even one-year-olds with disabilities. Or even to breed babies for spare parts. And Singer, now a professor at Princeton, continues his spiral into the moral abyss, by adding "there's no moral problem" with someone having sex with the...