Alcmaeon of Croton – Father of Neuroscience?

Here we present selected parts of the very interesting paper “Alcmaeon of Croton – Father of Neuroscience? Brain, Mind and Senses in the Alcmaeon’s Study” (JOURNAL OF NEUROLOGY AND NEUROSCIENCE, 2017), by Adam M Zemelka.

“Information on Alcmaeon (ca. 540 -? BC), included in the Lives and Opinions of Eminent Philosophers by Diogenes Laertius, is no more than fragmentary. Therefore it is not easy to reconstruct Alcmaeon’s biography and to precisely determine the years of his life. Comparing Alcmaeon’s age with Anaxagoras (ca. 500-428 BC) and Empedocles (ca. 495-435 BC), we come to the conclusion that they were not contemporaries, and at most the youth of these two philosophers fell on the decline of Alcmaeon’s life. Clarke and O’Malley are of the same opinion believing that Alcmaeon wrote his work between 480 and 440 BCE.

Croton, which he came from, was a scientific metropolis thanks to excellent medical school, run by Alcmaeon for some time. To this city – Democedes (one of the most famous
doctors in Hellas) arrived to practice medicine for five years (c. 530-525 BC). As G. Celestia points out, in Croton – there were both the Pythagorean school and the medical school. Alcmaeon certainly had connections with both.

(…) It should be underlined that pioneered by Alcmaeon empirical trend in Greek philosophy was later developed by Hippocrates (ca. 460-370 BC), Aristotle (ca. 384-322 BC), and Galen (ca. 130-210 CE). Importantly, Alcmaeon probably conducted autopsies on animal organisms. In ancient times, he was considered as a father of anatomy, which is proof of his very knowledgeable.

Diogenes Laertius defined Alcmaeon as a teacher, whose leading field was a medicine. However, the writer pointed out that medicine was not the only of his interest. Philosopher from Croton also conducted research in the field of natural philosophy, which was guided by the principle of opposites, expressed in the saying, “Most human things go in pairs”, which also Aristotle mentioned in the Metaphysics. Thus, he rejected the possibility of learning by similarities – just as later Anaxagoras did.

Favorinus in the Various stories admitted that Alcmaeon was the first Pythagorean philosopher who wrote a treatise On nature which title was given to many various papers in Antiquity.

(…) Aristotle said that Alcmaeon defined the nature of the celestial bodies as eternal, comparing them to the soul – immortal (as opposed to the body) and which is like the sun, in constant motion.

The philosopher of Croton believed that a person can rely on a limited analysis of the facts. And in consequence that only gods can know anything about what imperceptible.

(…) According to Alcmaeon, our health depends on the balance of properties, wet and dry, hot and cold, bitter, sweet, and so on, and that any disproportion leads to diseases. In his opinion, domination of even one is harmful to the body. He said that the disease develops, in some cases, the excess heat or cold, with some of the excess food in another fault of the blood, bone or brain. Moreover, we should take into account external factors as water quality, soil, environment and other factors causing disease. Thus, health depends on the equal distribution of proportion.

Alcmeon in his medical studies also dealt with what is now called embryology. He disagreed with the prevailing view in Greek science (next centuries preserved by Aristotle) that the offspring were born solely from the seed of a father, without
maternal material.

(…) Alcmaeon also explained the sex on a proportional basis. In his opinion, the sex of a
child was the same as the sex of the parent from which the greater number of semen; moreover, he believed that semen is included in the brain. Alcmaeon considered that equilibrium is a condition of health, what then Empedocles repeated. This equilibrium will be called homeostasis, but it will only be in the twentieth century i.e., 1929, thanks to the Walter Cannon’s article The Organization for Psychological Homeostasis.

As we know, Alcmaeon was the first scientist who thought that the brain plays a guiding role in the body (gr. hegemonikon). Exactly in the body, he invested the source of
intelligence.

Alcmaeon’s theory based on the Pythagorean beliefs that the brain is a source of mind, soul, and logic, and the heart he called the place of formation of feelings. Alcmaeon
claimed directly that the chief power in the human body is the brain, what Robert Doty compared to the Copernican or Darwinian breakthrough. It should be underlined, that
Alcmaeon certainly had a lot of courage and curiosity in conducting such studies. Therefore, he is similar to Copernicus or Darwin not only thanks to his discoveries but also because of his inner determination and huge obstinately. The Alcmaeon’s discovery is even more significant when we realize that for many centuries the view of the dominant role of the brain (encephalocentrism) will compete with the view of the central role of the heart (cardiocentrism). Alcmaeon initiated the right path, which was finally confirmed in modern times.

Alcmeon’s neurological investigation concerns not only an adult brain, but also the fetal period, and then years of human adolescence. According to the philosopher’s constatations – the head is already full development in utero, which does not mean that the brain gets the fullness of their potential. Finally, in the fourteenth year of life, as he claimed, the brain develops in man “perfect reason”, which was also the conviction of Zeno of Kitio and Aristotle.

Therefore, Alcmaeon seems to be the precursor of the organic equilibrium theory, which has survived until modern times. As he pointed out, the moderation called substantial
balance is the guarantee of human health.

(…) He mentioned food as one of the possible causes of disease states; for Hippocratic medicine the question of nutritionist was crucial. Alcmeon also wrote about the threat posed by the ongoing processes in the organs. It is all about the brain, which, like other organs, it can become a place where the various diseases are generated. Alcmaeon emphasized the importance of external factors from the environment – it seems to be the prototype of environmental medicine.

(…) According to Alcmaeon, a sensory cognition is associated with the brain, which is the source of disorders of sensory organs. James Garber called Alcmaeon the father of scientific psychology because of his belief in the biological basis of mental processes of man. This is a bold thesis, but it seems justified. Moreover, John Beare recognized Alcmaeon, Empedocles, Anaxagoras, Democritus (ca. 460-370 BC), Diogenes of Apollonia (5th century BC) and Plato (ca. 428-348 BC), as “psychologists”. He also contends that the idea of separation of metaphysics from the considerations of the human psychic sphere makes them the “fathers of scientific psychology”.

Alcmaeon expressly stated that all feelings have connections with the brain, and on the other hand, its trauma causes damage to the sensory organs. He suspected that the
obstruction of the ducts (gr. poroi) connecting the sensory organs to the brain leads to cognitive impairment.

As Crivellato and Ribatti emphasized – Alcmaeon used the term ksynienai which should be translated as “mixed” or “call together”. It expresses the complexity of the process of
cognition, in which information is perceived by the senses, which are processed by the brain. On the other hand, Friedrich Solmsen believes that the term – which most fully reflects the Alcmaeon’s belief about the role of the senses in the process of cognition (and their dependence on the brain) – is dehesthai or diadidonai, meaning “acceptance”, “receive”.

Alcmaeon claimed that a man is the only creature having the ability to understand (in other words – thinking) and that the other animals receive only sensory impressions, without the possibility to submit their reflection. Theophrastus pointed out that according to Alcmaeon, a perception is not the same what thinking is.

(…) according to Alcmaeon’s theory, the sensory organs are connected to the brain, and their patency provides to the correct receiving impressions. It is possible that he
observed the connection between the eyes and the brain at autopsy on the animal organisms. Therefore, Alcmaeon probably noticed yet unnamed the optic nerve. Chalcydius reported that Alcmaeon knew in detail the construction of the eye, thanks to an autopsy. Codellas underlines that undertaking such risky (from a cultural and religious point of view) actions made him a real natural scientist who was a pioneer in that kind operation. And although it is more likely that he was carrying out the animal dissections, neither does it take away the importance of his accomplishment. Solmsen and Longrigg share this point of view, claiming that Alcmaeon first noticed the optic nerve, so this discovery rightly attributed to him. In turn, Crivellato and Ribatti call observed by Alcmaeon connection – one of the poroi, that is, channels or vessels which today are rightly identified as nerves.

(…) We can interpret Alcmaeon’s concept of the vision as follows: inner fire escapes from the brain to the eyes, and then it performs the function of the detector in the eyes,
recognizing objects and reflecting their image. This process can be compared to explore the environment by touch. From the modern science’s point of view this explanation is not quite wrong (though trying to clarify the metaphors requires adequate reserve) – as we can see on the example of eyeballs’ optokinetic movements and the kinesthesia and somesthesia participating in the creation of an integrated threedimensional image. Because the image formed on the retina is two-dimensional as painted on a wall (with imperceptible thickness), the third dimension appears only on the path of integration with other senses, especially with the movement.

(…) The second sensation that Alcmaeon paid attention is hearing. On the issue of receiving sound impressions, he argued that the sound is produced as a result of the vacuum occurring in the ears, in which the air is reflected back coming sounds. This view was repeated by later philosophers. Alcmaeon believed that a person hears through the empty space in the ears, where the sound resonates due to the presence of air. Thus, all empty objects produce sound. Sound when entering the vacuum contained in the ears, then travels to the brain, where, according to Alcmaeon, it takes the proper
reception. Alcmaeon was probably the first Greek scholar who tried to explain the formation of sounds in relation to the anatomy of the ear.”

(The interested reader may find the whole paper here: http://www.jneuro.com/neurology-neuroscience/alcmaeon-of-croton–father-of-neuroscience-brain-mind-and-senses-in-the-alcmaeons-study.pdf)