Niels Stensen: a 17th century scientist with a modern view of brain organization.

In 1665 the Danish scholar Niels Stensen (1638-1686) reached Paris, where he pronounced a discourse on brain anatomy that was to orient neuroscientists for years to come. In his lecture, Stensen rejected ancient speculations about animal spirits and criticized René Descartes and his followers who, despite a poor knowledge of brain anatomy, elaborated complex models to explain the multifaceted function of what he considered the principal organ of the human mind. He advocated the need for studying the brain through a comparative, developmental and pathological convergent approach and called for appropriate dissection methods and accurate illustrations. His own careful anatomical studies permitted him to precisely depict many brain structures. After pioneering works in paleontology and geology, he devoted himself to theology. In 1677 Stensen converted from Lutheranism to Catholicism and, while working relentlessly as a bishop and apostolic vicar in Northern Europe, he died in self-imposed poverty at age 48.