This article reviews the 1681 edition of The Anatomy of the Brain, by Thomas Willis (1621-1675), which was first published in Latin in 1664. Although description of the circulation at the base of the brain is part of this text, the majority of the book is devoted to functional anatomic features of the brain. This is an early attempt by Willis to translate cadaveric brain anatomic features into assigned behavioral and neurophysiological functions. Extensive comparisons are made between "lower" animals and human subjects, emphasizing the differences in their intellects. This unique document ushered in the era of modern neuroanatomy and laid the groundwork for future neuroanatomic and neurophysiological investigations.