Animal spirits The substance Descartes (and others) thought was located in the cavities of the brain. When this substance moved via the nerves from the brain to the muscles, the muscles swelled and behavior was instigated.
Aristarchus of Samos (ca. 310–230 B.C.) Some- times called the Copernicus of antiquity, Aristarchus speculated that the planets, including the earth, rotate around the sun and that the earth rotates on its own axis, and he did so almost 1,700 years before Copernicus.
Bacon, Francis (1561–1626) Urged an inductive, practical science that was free from the misconceptions of the past and from any theoretical influences.
Bruno, Giordano (1548–1600) Accepted the mystical non-Christian philosophy of Hermetism and Coperni- cus’s heliocentric theory because he mistakenly believed that it supported Hermetism. He was burned at the stake for his beliefs.