"In 1957 he began taking pictures with an endoscope, an instrument that can see inside a body cavity, but when Lennart Nilsson presented the rewards of his work to LIFE’s editors several years later, they demanded that witnesses confirm that they were seeing what they thought they were seeing. Finally convinced, they published a cover story in 1965 that . . . created a sensation . . . [His] painstakingly made pictures informed how humanity feels about . . . well, humanity."
