Like many intellectual disciplines, the study of biology can be traced back to the Greek philosopher Aristotle. A true empiricist, Aristotle relied not on speculation but on dissections of organisms to uncover the principles that govern life processes.
However, despite his positive influence on the physical sciences, one glaring error of his stands out: “And of course, the brain is not responsible for any sensations at all. The correct view [is] that the seat and source of sensation is the region of the heart.”
Aristotle was not alone in this now ludicrous position. The Egyptians also hailed the heart as the center of thought and preserved it — not the brain — after death. One pre-Socratic thinker, Empedocles, taught that blood was the medium of thought and that therefore cognition depends on cardiac function.
On the other hand, other philosophers such as Alcmaeon of Croton noticed that the sense organs — the eyes, nose and mouth — all surrounded the brain. Therefore, it would be most efficient for the brain to receive these senses and direct actions accordingly.
Aristotle countered with the fact that much of physical and tactile sensation comes through touch, which can be felt anywhere in the body that receives blood. Therefore, it is actually the heart that is centrally located to receive information from every part of the body. Like most of Aristotle’s positions, his argument for the heart’s supremacy was quite strong at the time of his writing. He also pointed out that the heart responds to emotion, forms first in development and is naturally hot in temperature. His premises can be viewed as more or less accurate; he just happens to be completely wrong when it comes to his thesis.
One must admit that Aristotle’s picture of cognition, though incorrect, is nonetheless poetic. He does not completely dismiss the brain; rather, he describes the brain as responsible for “cooling” the heart. He describes something like homeostasis, in which the brain and heart must counterbalance one another for proper decision making. This aligns with his thoughts on the golden mean, or the idea that virtue lies in the middle of two extreme vices — so courage is a virtue, in between the vices of cowardice and recklessness.
Interestingly enough, then, Aristotle still attributed mental illness to brain dysfunction. If the brain cannot absorb heat from the heart, the heart will quickly and recklessly react to any disturbance. Just think about the feeling of anger: Your heart beats faster and you feel a bit hotter. According to Aristotle’s dissections, the brain was naturally cold and in a good position to balance the heat. While we metaphorically advise the aggressors in our lives to “cool their tempers,” this advice is grounded in an ancient understanding of physiology.
Unknowingly at the time, Aristotle identified the sympathetic nervous system: In response to stress, the nervous system prepares the body for fight or flight. Among many other biological changes, the preparation consists of improving blood circulation by raising the heart rate. However, this rise in heart rate is a consequence of the response, not responsible for it. Really, it is the nervous system, an extension of the brain that governs heart rate, not the other way around.
But while science has moved on, Aristotle’s picture of cognition still breathes in our language. We still think of the heart as the seat of emotion and the brain as the center of cool, logical thinking. Perhaps this is further testament to Aristotle’s impressive legacy; his influence has been cast so far that even his wrong ideas have left a footprint on modern language.
Ayan Mandal is a junior in the college. Brain History appears every other Tuesday.