Alcmaeon of Croton was a Greek pre-Socratic physician-philosopher, introduced the concept that mind and soul are located in the brain. Alcmaeon made observations about seeing, hearing, tasting, and smelling and distinguished perception from understanding.
Background
Alcmaeon of Croton was born in 540 B.C. in Crotona, Magna Graecia, and was the son of Peirithoos. Crotona was a prosperous colony in Magna Graecia founded c. 710 BC. It was a significant intellectual center in the south of Italy owing to both its medical reputation and Pythagorean association. Information on Alcmaeon himself included in the Lives and Opinions of Eminent Philosophers by Diogenes Laertius, and is no more than fragmentary. Therefore it is not easy to reconstruct Alcmaeon’s biography and to precisely determine the years of his life.
Education
Alcmaeon was a pupil of Pythagoras.
Career
Alcmaeon was is often reported to have been a physician. There is no support for this in ancient sources, however, although Diogenes Laertius stated that Alcmaeon “wrote mostly about medical affairs.” As far as we can judge, he also wrote about meteorological and astrological problems and about such philosophical questions as the immortality of the soul. It may therefore be best to call him a natural philosopher, deeply versed in medicine, who was in close contact with both the Pythagoreans and the physicians in Crotona (in this connection we may also think of his contemporary, the physician Democedes of Crotona). One must also keep in mind that at that time the “physiological” side of medicine was treated predominantly by philosophers, Hippocrates being the first to “separate medicine from philosophy,” as Celsus states in the preface to De re medicina. Aristotle’s lost writing Against Alcmaeon apparently concerned Alcmaeon as a philosopher.
In the history of science Alcmaeon is especially important for two reasons: he may have written the very first Greek prose book, a physikos logos; and he furnished medicine with the first material for a fundamental intellectual mastery of the nontraumatic internal diseases. He defined health as “the isonomy (balance) of forces” (that is, a balance of the opposite bodily qualities of cold and warm, bitter and sweet, and so forth) and internal disease as the “monarchy” of one of these “forces.” He further divided the causes of disease into disorders of environment (climatic factors and the like), of nutrition, and of physical mode of living (exertion and such). From these definitions he formulated the bases of a general pathophysiology of internal diseases; similar hypotheses were made by the Hippocrateans. Apparently Alcmaeon clearly recognized the conjectural character of his formulae; they constituted, for him, an “opinion about the invisible.”
Alcmaeon also seems to have engaged in dissection, especially ocular dissection for the investigation of the visual process. Obviously, the word exsectio in Chalcidius’ report is to be taken in this sense; it could hardly refer to a surgical operation on a man since human dissection in a systematic form was, for religious reasons, neither then nor until much later possible in Greece. Among the pre-Socratic philosophers of around 500 B.C., Alcmaeon is the one most closely connected with medicine and therefore had the greatest significance for medicine per se, although he himself did not praetice as a physician.
Views
According to Theophrastus, Alcmaeon was the first Greek thinker to distinguish between sense perception and understanding and to use this distinction to separate animals, which only have sense perception, from humans, who have both sense perception and understanding. Alcmaeon is also the first to argue that the brain is the central organ of sensation and thought. There is no explicit evidence, however, as to what Alcmaeon meant by understanding. The word translated as understanding here is suniêmi, which in its earliest uses means “to bring together,” so that it is possible that Alcmaeon simply meant that humans are able to bring the information provided by the senses together in a way that animals cannot.
Animals have brains too, however, and thus might appear to be able to carry out the simple correlation of the evidence from the various senses, whereas the human ability to make inferences and judgments appears to be a more plausible candidate for the distinctive activity of human intelligence. It is possible that we should use a passage in Plato’s Phaedo to explicate further Alcmaeon’s epistemology. The passage is part of Socrates’ report of his early infatuation with natural science and with questions such as whether it is the blood, or air, or fire with which we think. He also reports the view that it is the brain that furnishes the sensations of hearing, sight, and smell.
This corresponds very well with Alcmaeon’s view of the brain as the central sensory organ and, although Alcmaeon is not mentioned by name, many scholars think that Plato must be referring to him here. Socrates connects this view of the brain with an empiricist epistemology, which Aristotle will later adopt. This epistemology involves three steps: first, the brain provides the sensations of hearing, sight and smell, then, memory and opinion arise from these, and finally, when memory and opinion achieve fixity, knowledge arises. Some scholars suppose that this entire epistemology is Alcmaeon’s, while others more cautiously note that we only have explicit evidence that Alcmaeon took the first step.
Also, through systematic observations, Alcmaeon brought many things to light about the characteristics of the eye and the presence of channels connecting head sensory organs to the brain. He stated that the soul was immortal and introduced the tekmairesthai doctrine, through which the ideas of anamnesis and prognosis gave birth. We highlight his contributions to medical thought, and especially to neuroscience, which reveal Alcmaeon to be a thinker of considerable originality and one of the greatest philosophers, naturalists, and neuroscientists of all time.
