Thomas Willis FRS (27 January 1621 – 11 November 1675) was an English physician who played an important part in the history of anatomy, neurology, and psychiatry,[1] and was a founding member of the Royal Society.

[16] Henry Stubbe became a polemical opponent of the Society, and used his knowledge of Willis's earlier work before 1660 to belittle some of the claims made by its proponents.

[3] He had a successful medical practice, in which he applied both his understanding of anatomy and known remedies, attempting to integrate the two; he mixed both iatrochemical and mechanical views.

[18][19] According to Noga Arikha: Willis combined the physician's expert anatomical sophistication with the fluent use of an interpretive apparatus that see-sawed between novelty and tradition, Galenism and Gassendist atomism, iatrochemistry and mechanism.

This work coined the term neurology,[22] and was not the result of his own personal and unaided exertions; he acknowledged his debt to Sir Christopher Wren, who provided drawings, Thomas Millington, and his fellow anatomist Richard Lower.

In 1667 Willis published Pathologicae cerebri, et nervosi generis specimen, an important work on the pathology and neurophysiology of the brain.

In 1672 he published the earliest English work on medical psychology, Two Discourses concerning the Soul of Brutes, which is that of the Vital and Sensitive of Man.

In the cerebellum he remarks the arborescent arrangement of the white and grey matter and gives a good account of the internal carotids and the communications which they make with the branches of the basilar artery.

[26] He observed what had been known for many centuries in India, China and the Arab world, that the urine is sweet in patients (glycosuria),[27] however he hadn't coined the term mellitus as it is commonly claimed[citation needed].

The philosopher Richard Cumberland quickly applied the findings on brain anatomy to argue a case against Thomas Hobbes's view of the primacy of the passions.

Willis's books, including Cerebri anatome and selected works in five volumes (1664) are listed as once in the library of Sir Thomas Browne.

Between 1724 and 1730, Browne Willis rebuilt St. Martin's Church on the site of the old Chantry Chapel of St. Margaret and St. Catherine at Fenny Stratford.