That there is a continuous link from humans to gorillas, with the intermediate species merely long dead, is beyond the understanding of speciesists. Tie the label Homo sapiens even to a tiny piece of insensible embryonic tissue, and its life suddenly leaps to infinite, incomputable value.... Self-styled pro-lifers, and others that indulge in footling debates about exactly when in its development a foetus becomes human, exhibit the same discontinuous mentality. Human, to the discontinuous mind, is an absolutist concept. There can be no half measures. And from this flows much evil.