Renaissance Europe, 1500-Mid1600 C.E.

Galenic anatomy remained the prevailing doctrine until the 16th century, while Nicholas Copernicus was spearheading the scientific revolution (Gross, 1987; National Institutes of Health, 2000). By performing Galenic dissections for what was mostly demonstration (medical school demonstrations tended to gather a lot of crowds), Andreas Vesalius began to understand how Galen had not dissected human beings to study anatomy, and most of his work was conjecture. He began to mock Galen for not using human subjects, but he accepted Galen’s pneumatic theory as fact. While he mocked Galen for lack of knowledge, he admitted that while much of human anatomy could be discovered and known, he did not think that memory and thinking could be explained through anatomical study.

Descartes and the Reflex Arc

File:Frans Hals - Portret van René Descartes.jpgRene Descartes

Rene Descartes sought to make philosophy as exact an art as mathematics. C. 1633, he completed a work called De homine detailing what came to be known as the reflex arc. He proposed that reactions to external stimuli begin in the nerve fibrils, and continue up through the body, and eventually displace animal spirits in the brain (Wozniak, 1995). The interrupted flow of the animal spirits was directed to the appropriate body part, and a reaction occurred.

Descartes was not independent of the European desire to place the soul somewhere within the mind. He designated the pineal gland as the locus of the soul, as it was not bilaterally duplicated, or two mirror image halves, as the rest of the brain is. He was also a strong believer in the movement of animal spirits, much like Galen (Findlen, 1998).

Thomas Willis and the Cerebri Anatome

File:Thomas Willis ODNB.jpgThomas Willis
Thomas Willis's Cerebri Anatome (On the Anatomy of the Brain), open to show engravings of the human brain on the left page and of the sheep brain on the right page.A Photographic Excerpt from Thomas Willis’ Cerebri Anatome, 1664

The above photo of the Cerebri Anatome shows a human brain on the left and a sheep brain on the right side, showing one of the best illustrations of the human brain from the 18th century. Thomas Willis, the man responsible for the Cerebri Anatome, contributed more anatomical knowledge to the concept of the reflex arc that Descartes discovered a few decades prior (O’Connor, 2003).

Up until Willis wrote this text, some rudimentary descriptions of the brain already existed, and Willis sought to expand upon those descriptions. His ultimate goal was to find a connection between the brain and the soul, but in his search for that connection, he provided descriptions of the brain that became definitive doctrine for the next hundred years or so.

If you have a Gmail account, a free ebook copy of the Cerebri Anatome is available through the External Links page.



Findlen, P., (1998). A history of the nervous system. Retrieved from

Gross, C. G. (1987). Early History of Neuroscience. In Adelman, G. (ed.), Encyclopedia of Neuroscience, 843-847.

National Institutes of Health, (2000). The balance of passions. Retrieved from

O’Connor, J. P. B., (2003). Thomas Willis and the background to cerebri anatome. Journal of the Royal Society of Medicine, 96, 139-143.

Wozniak, R. H., (1995). Rene Descartes. Retrieved from

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