Early history in Psychology 5. Rene Descartes

René Descartes was born in France on March 31, 1596. In May 1597, his mother, Geneviève Brocquet, died a few days after giving birth to a stillborn child. His father, Joachim Descartes, was a member of the Parliament of Brittany in Rennes. René lived with his grandmother and his great uncle. Although the Descartes family was Roman Catholic, the Plateau region was controlled by the Protestant Huguenots.

In 1607, due to his fragile health, Descartes entered the Jesuit college Royal Henry-Le-Grand at La Flèche, where he was introduced to mathematics and physics, including the work of Galileo. While at the college, he first encountered Hermetic mysticism. After graduating in 1614, he studied for two years at the University of Poitiers, earning a baccalaureate and a license in both canon and civil law in 1616.

In accordance with his father's wishes that he should become a lawyer, Descartes initially pursued legal studies. However, driven by his ambition to become a professional military officer, he moved to Paris. In 1618, he joined the Protestant Dutch States Army as a mercenary in Breda, serving under the Catholic Duke Maximilian of Bavaria from 1619 onward.

Descartes was present at the Battle of White Mountain near Prague in November 1620, a decisive conflict in the early stages of the Thirty Years' War.

Philosophically, Descartes is renowned for his emphasis on human reason. He began with the radical premise that the only way to attain certainty is to doubt everything. He resolved to reject all beliefs in which he could imagine the least doubt in order to discover if anything remained entirely indubitable. This methodical skepticism led to his famous dictum: "Cogito, ergo sum" ("I think, therefore I am").

Descartes also explored the nature of consciousness. He argued that one cannot deny the existence of one’s own mind while using the mind itself to deny it, highlighting the self-evident nature of consciousness.

Despite these insights, near-death experiences (NDEs) and out-of-body experiences (OBEs) appear to occur even when the brain is not functioning normally, presenting challenges to current scientific models of mind-body interaction. These phenomena occur in approximately nine percent and two percent, respectively, of cardiac arrest cases with successful resuscitation and may expand our understanding of consciousness and its relation to brain activity.

From the certainty of his own doubting, Descartes built a philosophy prioritizing the workings of the individual mind over immediate sensory experience and received wisdom.

Descartes famously postulated a radical mind-body dualism, claiming that the universe consists of two utterly distinct substances: mind (a thinking substance, or res cogitans) and matter (a physical substance, or res extensa). He maintained that the natures of mind and body are entirely different and that each could exist independently.

Descartes is sometimes considered the founding father of modern philosophical psychology and is arguably the most famous dualist. He believed there was a clear division between mind and body.

He proposed that the mind influenced the brain through the pineal gland, a small, singular structure located near the brain's ventricles in the center of the brain. Descartes theorized that the pineal gland moved the "animal spirits" within the ventricles and sent them throughout the body via nerves to control behavior and movement. Although this theory is now discredited, at the time it was a logical explanation, especially considering the then-recent discovery of the heart’s function as a blood pump.

The pineal gland was Descartes’s ideal site for mind-body interaction because it is a unique, singular brain structure positioned centrally, unlike most brain structures, which exist bilaterally in both hemispheres.

He separated mental phenomena from the mechanistic explanation he provided for the workings of matter and material objects, including the human body. He divided the body into ten physiological systems encompassing faculties such as memory and imagination, alongside purely physiological functions like digestion, circulation, and respiration.

Descartes’s rationalistic ideas laid the groundwork for the Enlightenment and became the dominant philosophical system until challenged by the works of David Hume (1711–1776) and Immanuel Kant (1724–1804).

Although many of Descartes’s individual arguments have been discredited, his overall conception of mind-body dualism profoundly influenced subsequent generations of philosophers and psychologists.