What Would Thomas Henry Huxley Have Made of Prion Diseases

“Science is nothing but trained and organized common sense, differing from the latter only as a veteran may differ from a raw recruit.”^a Prion disease is a disease of the second half of the twentieth century, but the scientific method that has elucidated this fascinating group of diseases is much older. As an illustration of this, this chapter considers the way in which a nineteenth century scientist might have reacted to the challenge that prion disease has presented. T. H. Huxley (1825-1895) was an ardent naturalist, who traveled around the world collecting specimens, and who peered down the microscope (1 ). He amassed vast amounts of data, and could work prodigiously hard. His approach to science can be judged from some of things that he said. He was a confrontational character, and would undoubtedly have joined in the arguments that led to the concept of prion disease, if he had lived a century later.