When David Marr at MIT moved into computer vision, he generated a lot of excitement, but he hit up against the problem of knowledge representation; he had no good representations for knowledge in his vision systems.
Bio: Paracelsus, born Philippus Aureolus Theophrastus Bombastus von Hohenheim, was a Swiss German philosopher, physician, botanist, astrologer, and general occultist. He is credited as the founder of toxicology.