What scientific idea is ready for retirement? ESSENTIALISM (...) Moral controversies such as those over abortion and euthanasia are riddled with the same infection. At what point is a brain-dead accident-victim defined as "dead"? At what moment during development does an embryo become a "person"? Only a mind infected with essentialism would ask such questions. An embryo develops gradually from single-celled zygote to newborn baby, and there's no one instant when "personhood" should be deemed to have arrived. The world is divided into those who get this truth and those who wail: "But there has to be some moment when the foetus becomes human." No, there really doesn't, any more than there has to be a day when a middle-aged person becomes old. It would be better – though still not ideal – to say the embryo goes through stages of being a quarter human, half human, three quarters human… The essentialist mind will recoil from such language...
"Examinai tudo. Retende o bem", I Tessalonicenses 5:21