The cardiocentric hypothesis was the historical belief that the

heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...

controls

sensation Sensation (psychology) refers to the processing of the senses by the sensory system. Sensation or sensations may also refer to: In arts and entertainment In literature * Sensation (fiction), a fiction writing mode * Sensation novel, a Britis ...

, thought, and body movement. Cardiocentrism was first derived from the ancient Egyptian belief that the heart was the house of thought and soul. This idea was later accepted by

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

philosophers such as

Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of ph ...

, Diocles, and Praxagoras of Cos. With the development of modern science and

anatomy Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having it ...

, the cardiocentric hypothesis was eventually proven incorrect, though its emphasis in Antiquity may have helped contribute to the discovery of the cardiovascular system and influenced the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...

and Islamic Ascendancy. An opposing theory called "cephalocentrism", which proposed that the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...

played the dominant role in controlling the body, was first introduced by

Pythagoras Pythagoras of Samos ( grc, Πυθαγόρας ὁ Σάμιος, Pythagóras ho Sámios, Pythagoras the Samian, or simply ; in Ionian Greek; ) was an ancient Ionian Greek philosopher and the eponymous founder of Pythagoreanism. His politi ...

in 550 BC, who argued that the soul resides in the brain and is immortal. His statements were supported by

Plato Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...

Hippocrates Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history o ...

, and

Galen of Pergamon Aelius Galenus or Claudius Galenus ( el, Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen () or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one of ...

. Plato believed that the body is a "prison" of the mind and soul and that in death the mind and soul become separated from the body, meaning that neither one of them could die.

History

El pesado del corazón en el Papiro de Hunefer

In ancient Egypt, people believed that the heart is the seat of the soul and the origin of the channels to all other parts of the body, including

arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...

vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenat ...

s, nerves, and

tendon A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...

s. The heart was also depicted as determining the fate of ancient Egyptians after they died. It was believed that

Anubis Anubis (; grc, Ἄνουβις), also known as Inpu, Inpw, Jnpw, or Anpu in Ancient Egyptian () is the god of death, mummification, embalming, the afterlife, cemeteries, tombs, and the Underworld, in ancient Egyptian religion, usually depict ...

, the god of

mummification A mummy is a dead human or an animal whose soft tissues and organs have been preserved by either intentional or accidental exposure to chemicals, extreme cold, very low humidity, or lack of air, so that the recovered body does not decay furt ...

, would weigh the deceased person's heart against a feather. If the heart was too heavy, it would be considered guilty and consumed by the

Ammit Ammit (; egy, ꜥm-mwt, "devourer of the dead";Erman, Adolf; Grapow, Hermann (1926-1961) ''Wörterbuch der ägyptischen Sprache'', Berlin: Akademie-Verlag, volume 1, page 184.9 also rendered Ammut or Ahemait) was a goddess in ancient Egyptian ...

, a mythological creature. If it was lighter than the feather, the spirit of the deceased would be allowed to go to heaven. Therefore, the heart was kept in the mummy while other organs were generally removed. However, the ancient Greeks,

promoted the cardiocentric hypothesis based on his experience with animal dissection. He found that certain primitive animals could move and feel without the brain, and so deduced that the brain was not responsible for movement or feeling. Apart from that, he pointed out that the brain was at the top of the body, far from the centre of the body, and felt cold. He also performed anatomical examinations after strangling the specimen, which would cause

vasoconstriction Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vess ...

of the

arteriole An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries. Arterioles have muscular walls (usually only one to two layers of smooth muscle cells) and are the primar ...

s in the

lungs The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side ...

. This likely had the effect of forcing blood to engorge the veins and make them more visible in the following dissection. Aristotle observed that the heart was the origin of the veins in the body, and concluded that the heart was the centre of the psycho-physiological system. He also stated that the existence of

pneuma ''Pneuma'' () is an ancient Greek word for "breath", and in a religious context for " spirit" or "soul". It has various technical meanings for medical writers and philosophers of classical antiquity, particularly in regard to physiology, and is ...

in the heart was to function as a messenger, traveling through blood vessels to produce sensation. Movement of body parts was thought to be controlled by the heart as well. From Aristotle's perspective, the heart was composed of sinews which allowed the body to move. In the fourth century BC,

Diocles of Carystus Diocles of Carystus (; el, Διοκλῆς ὁ Καρύστιος; la, Diocles Carystius; also known by the Latin name Diocles Medicus, i.e. "Diocles the physician"; c. 375 BC – c. 295 BC) was a well-regarded Greek physician, born in Carystus, ...

reasserted that the heart was the physiological centre of sensation and thought. He also recognised that the heart had two cardiac ears. Although Diocles also proposed that the

left brain The lateralization of brain function is the tendency for some neural functions or cognitive processes to be specialized to one side of the brain or the other. The median longitudinal fissure separates the human brain into two distinct cerebra ...

was responsible for intelligence and the right one was for sensation, he believed that the heart was dominant over the brain for listening and understanding. Praxagoras of Cos was a follower of Aristotle's cardiocentric theory and was the first one to distinguish arteries and veins. He conjectured that arteries carry pneuma while transporting blood. He also proved that a

pulse In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the n ...

can be detected from the arteries and explained that the arteries' ends narrowed into nerves. The Islamic philosopher and physician Avicenna followed

, believing that one's spirit was confined in three chambers of the brain and accepted that nerves originate from the brain and

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...

, which control body movement and sensation. However, he maintained the earlier cardiocentric hypothesis. He stated that activation for voluntary movement began in the heart and was then transported to the brain. Similarly, messages were delivered from a peripheral environment to the brain and then via the

vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...

to the heart. In the Middle Ages, the German Catholic friar

Albertus Magnus Albertus Magnus (c. 1200 – 15 November 1280), also known as Saint Albert the Great or Albert of Cologne, was a German Dominican friar, philosopher, scientist, and bishop. Later canonised as a Catholic saint, he was known during his li ...

made contributions to physiology and biology. His treatise was based on Galen's cephalocentric theory and was profoundly affected by Avicenna's preeminent Canon, which itself had been influenced by Aristotle. He combined these ideas in a new way which suggested that nerves branched off from the brain but that the origin was the heart. He concluded that philosophically, all matters originated from the heart, and in the corporeal explanation, all nerves started from the brain. William Harvey (1578-1657) Venenbild

William Harvey William Harvey (1 April 1578 – 3 June 1657) was an English physician who made influential contributions in anatomy and physiology. He was the first known physician to describe completely, and in detail, the systemic circulation and propert ...

, an early modern English physiologist, also agreed with Aristotle's cardiocentric view. He was the first to describe the basic operation of the circulatory system, by which blood was pumped by the heart to the rest of the body, in detail. He explained that the heart was the centre of the body and the source of life in his treatise ''De Motu Cordis et Sanguinis in Animalibus''.

The cephalocentric perspective

Hippocrates of Kos Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history of ...

was the first to suggest that the brain was the seat of the soul and intelligence. From his treatise ''De morbo sacro'', he pointed out that the brain controls the rest of the body and is responsible for sensation and understanding. Apart from that, he believed that all feelings originated from the brain.

was also a supporter of cephalocentricism. From his perspective, the soul was the essence of humanity, and he devised the tripartite theory of the soul which states that there are three soul species in the body. The one regarded as “immortal” and “divine” was in the brain and controlled voluntary movement. The other two were located in the chest and near the

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...

, which were responsible for feeling and desire.

was a biologist and physician. His approach to the investigation of the brain was due to his rigorous anatomical methodology. He pointed out that only correct dissection will support the incontrovertible statement. He reached the conclusion that the brain was responsible for sensation and thought, and that nerves originated at the spinal cord and brain.

History

The cephalocentric perspective

References

Further reading