SOUL AND MIND That the soul of our grandam might haply inhabit a bird (iv ii 50–1) And when Shylock is abused in The Merchant of Venice, the possibility is raised of migration in the reverse direction Thou almost mak’st me waver in my faith To hold opinion with Pythagoras That souls of animals infuse themselves Into the trunks of men (iv i 130–3) Pythagoras did not oVer philosophical arguments for survival and transmigration; instead he claimed to prove it in his own case by identifying his belongings in a previous incarnation He was thus the Wrst of a long line of philosophers to take memory as a criterion of personal identity (Diodorus 10 2) His contemporary Alcmaeon seems to have been the Wrst to oVer a philosophical argument in this area, claiming, by a dubious inference from an obscure premiss, that the soul must be immortal because it is in perpetual motion like the divine bodies of the heavens (Aristotle, de An 405a29–b1) Empedocles adopted an elaborate version of Pythagorean transmigration as part of his cyclical conception of history As a result of a primeval fall, sinners such as murderers and perjurers survive as wandering spirits for thrice ten thousand years, incarnate in many diVerent forms, exchanging one hard life for another (DK 31 B115) Since the bodies of animals are thus the dwelling places of punished souls, Empedocles told his followers to abstain from eating living things In slaughtering an animal you might even be attacking your own son or mother (DK 31 B137) Moreover, transmigration is possible not only into animals but also into plants, so even vegetarians should be careful what they eat, avoiding in particular beans and laurels (DK 31 B141) After death, if you had to be an animal, it was best to become a lion; if a plant, best to become a laurel Empedocles himself claimed to have experienced transmigration not only as a human but also in the vegetable and animal realm I was once in the past a boy, once a girl, once a tree, Once too a bird, and a silent Wsh in the sea (DK 31 B117) 231