René Descartes was a nice guy, but...

René Descartes may have been the "first modern thinker" in his belief that everything should be doubted and everything asserted must be proved, but he wasn't perfectly modern in his personal conduct. In his regard for the sanctity of nonhuman life, he was every bit a renaissance man.

He believed that the human soul was located in the pineal gland because (he thought) animals didn't have them. And so, because they didn't have souls, René concluded, they couldn't feel pain. And that made it perfectly okay in the brilliant scientific, enlightened mind of René Descartes to gash open animals like dogs and monkeys in living vivisection session, ignoring the plaintive cries of torment wailing from the mouths of the poor dying beasts.

Good on ya, René--make those critter suffer.