Cardiocentric Neurophysiology: The Persistence of a Delusion

Abstract

Aristotle is well known to have taught that the brain was a mere coolant apparatus for overheated blood and to have located the hegemonikon in the heart. This teaching was hotly disputed by his immediate successors in the Alexandrian Museum, who showed that the brain played the central role in psychophysiology. This was accepted and developed by the last great biomedical figure of classical antiquity — Claudius Galen. However, Aristotle's cardiocentric theory did not entirely disappear and this article traces its influence through the Arabic physicians of the Islamic ascendancy, into the European Middle Ages where Albertus Magnus' attempt to reconcile cardiocentric and cerebrocentric physiology was particularly influential. It shows how cardiocentricity was sufficiently accepted to attract the attention of, and require refutation by, many of the great names of the Renaissance, including Vesalius, Fernel, and Descartes, and was still taken seriously by luminaries such as William Harvey in the mid-seventeenth century. The article, in rehearsing this history, shows the difficulty of separating the first-person perspective of introspective psychology and the third-person perspective of natural science. It also outlines an interesting case of conflict between philosophy and physiology.

Keywords:

• Aristotle
• Hippocrates
• Avicenna
• Albertus Magnus
• Vesalius
• Descartes
• Hegemonikon
• heart
• brain

Notes

¹Recent studies have shown that heat loss through the scalp only averages about 10% of total body heat loss, although this may rise to nearly 50% on the onset of vigorous exercise before falling back to its original 10% when other thermoregulatory mechanisms, especially skin vasodilation and perspiration, begin to take effect.

²Although the concept of “pneuma” was common in much early thought (Smith, Frixione, Finger, & Crowther, 2012) this, according to Solmsen (1968), seems to be the first time it was regarded as internally generated. The concept appears in a bewildering variety of contexts in Aristotle's works. In his treatise on reproduction, he uses it to explain how the sperm transfers locomotion and sensation to the offspring and writes that it is “analogous to the element of the stars” (De generatione animalium, 736b35). In De respiratione (479b20–479b25), he writes that its “rushing together” in the heart produces the palpitations of fear and, when it is crushed into a tiny space, life is sometimes extinguished and “animals die of fright.” Most importantly, in the present context, its presence in the heart is, he writes, responsible for its pulsatile movements and that these movements, varying in response to the emotions, cause the body to move (De motu animalium, 703a20–703a25).

³Aristotle conceived the innate pneuma to inhabit not only the sensory passages (our nerves) but also to be mixed with the blood in the blood vessels (Peck, 1942).

⁴Frampton points out that this passage may be a later addition to the Aristotelian corpus rather than the Stagirite's own thought (Frampton, 2008, p. 78).

⁵ Generation of Animals,743a1–743a5: “From the heart the blood-vessels extend throughout the body as in the anatomical diagrams which are represented on the wall.”

⁶Detail of Avicenna's ventricular neuropsychology may be found in Rahman (1952).

⁷Avicenna (Canon, I, 1) as quoted in Frampton (2008, p. 370). Avicenna, following Aristotle, makes a philosophical argument for the primacy of the heart in the Kitāb al Najāt, Book II, Chapter XV (see Rahman, 1952, p. 66).

⁸Avicenna (Canon I, 1), as quoted in Frampton (2008, p. 370).

⁹Albert the Great's significance in establishing natural philosophy in medieval Europe was recognized in 1941 by Pope Pius XII, when he named him as patron saint of science. Pope Benedict XVI, in a 2010 address to the Faithful in St. Peter's Square, emphasized that Albert's great achievement was (and is) to show that natural philosophy (science) and theology are not irreconcilable but different approaches to the world we experience.

¹⁰Albertus, On Animals, Bk. 1, Tr. 2, Ch. XVIII, p. 356 (as translated by Kitchell & Resnick, 1999, p. 178).

¹¹Albertus, Questions concerning Aristotle's On animals, III, 7 (transl. Resnick & Kitchell, 2008, pp. 125–126).

¹²Keele observes that this is the first experiment on the nervous system since the times of Galen, a thousand years before (Keele, 1952, p. 523).

¹³The French translation of Descartes (1647) specifically includes in “the surrounding area” the “diaphragm.” This seems to bring us right back to the beginning of the tradition with the Pythagorean neuropsychology of Plato's Timaeus.