In this book the uncertainty as to who wrote the aphorisms seems irrelevant, since it would be only of an academic interest. The two books are combined and appear for the first time in English. This is regrettable because the French edition preceded the English one by a hundred years, and the Spanish edition by a much longer period. It does show a very scholarly intellect of the Fifth Century b.c. looking for scientific answers. It demonstrates clearly how observation and theory could misguide even a genius by applying simple analogies. Hippocrates did experiment with animals, but since dissection and/or experiments on human beings were not practiced until the Third Century b.c. (Herophilus and Erasistratus), the pitfall of applying what is found in animals to human beings is very well demonstrated. Despite his brilliant clinical descriptions, his reasoning by analogy led him theoretically to untenable findings.