Alcmaeon (c. 6th c. BC) was a contemporary of Pythagoras. He is known as philosopher and physiologist. He seems to be the first who supported the significance of the brain as the seat of consciousness and intelligence as well as he practiced dissection of human bodies for research purposes. For Alcmaeon the soul is the source of life. The soul is  immortal yet we die because we cannot join the beginning with the end. He also stated that cosmic harmony is the harmony between pairs of contraries. Alcmaeon also believed that that health consists in the equilibrium of the body’s component contraries.

Fragments and Testimonies

Fr. 1: Concerning things that are not perceptible [and concerning mortal things] the gods have clarity, but insofar as it is possible for human beings to judge ...

Fr. 2: Human beings perish because they are not able to join their beginning to their end.

Fr. 4: Alcmaeon said that the equality (isonomia) of the powers (wet, dry, cold, hot, bitter, sweet, etc.) maintains health but that monarchy among them produces disease.

A5: All the senses are connected in some way with the brain. As a result, they are incapacitated when it is disturbed or changes its place, for it then stops the channels, through which the senses operate.

Translated by C. Huffman