The Roman author Celsus praised Hippocrates as the first to separate medicine from the 'studium sapientiae', the study of wisdom, or, as we would say, 'philosophy'. 1 If he intended by this to suggest that after Hippocrates medicine and philosophy went their separate ways, and that neither learned or borrowed from the other, he was considerably mistaken. 2 Even as some of the texts in the Hippocratic Corpus were being composed, the philosopher Plato was making use of medical data for his own philosophical purposes, as well as putting forward an explanation for illness that was to have a long-lasting impact on the intellectual world.
We have already seen that Plato referred on several occasions in his dialogues to Hippocrates as the leading representative of medicine of his day, and in his Second Letter he mentioned his own acquaintance with the doctor Philistion of Locri. 3 His letter expressed the hope that Philistion would be allowed by his master, the tyrant Dionysius II of Syracuse, to come to Athens, although whether he ever did so is far from clear. 4 Plato is known to have made three visits to S. Italy and Sicily, in about 387, 367 and 362 BC, and may well have met with Philistion on any of these occasions. However, the authenticity of this letter has been frequently called into question, and a link between the two men could easily have been a later rationalisation of the ways in which some of Plato's theories come very close to those of Philistion as reported in the Anonymus Londinensis papyrus.
Philistion believed in three general causes of disease, which he then subdivided. The first (internal) cause was an excess or a deficiency in one of the four 'forms', hot, cold, wet and dry. The second (external) was the presence of wounds or sores, or the result of an excess or deficiency of external heat and cold, of inopportune changes from one to the other, or simply of wrong nutriment. The third and last cause was some impediment to the flow of air into or out of the body. 5 In his Timaeus, Plato produced two explanations that are very similar to the first and last of Philistion's: imbalances and irregularities within the four elements, and the failure of air to move properly into and out of the body. Where there is no breath, the body begins to rot; where there is too much, the air forces its way through where it should not, and causes painful swellings, sweatings and distortions. 6