Alcmaeon was from Croton (a Greek city-state in Italy). He lived during the early part of the 5th century and was a pupil of Pythagoras. He was a physician as well as a philosopher. He was believed by the Greeks to be the first to undertake dissections and the first to write a work on natural science. He believed that our senses and consciousness are connected to the brain. He conjectured on how our senses work. Men die but he believed that the soul and everything in the Heavens was eternal because they are always in motion. Men understand where as animals do not, that is their main difference. He believed that most human things come in pairs and he believed that health is acheived through moderation.