Anatomist Santiago Ramon y Cajal was the first to see—and illustrate—what neurons really do. His exquisitely detailed drawings changed our understanding of the brain and nervous system. Cajal relentlessly pursued his microcopic study of animal tissues, leading to an essential discovery: Brain signals jump from cell to cell rather than flow through a continuous web of fibers, as was believed at the time.
"Accept the view that nothing in nature is useless, even from the human point of view. Even … where it may not be possible to use particular scientific breakthroughs for our comfort and benefit, there is one positive benefit—the noble satisfaction of our curiosity."
By the time of this 1915 photograph, taken at his Madrid laboratory, Cajal (pointing) was a great man of science. He was ambivalent about that role. “Like vehement and rude friendship, among us fame bruises while it caresses; it kisses but it crushes,” he wrote.