The theory and practice of medicine is not usually associated with philosophers or the history of philosophy. Except for recognition of the ethical aspects of many medical decisions (for example, abortion, end-of-life issues, and cost of care), medical doctors do not seek out philosophical opinions, and philosophers do not view medicine as part of their normal range of subjects. Nevertheless, until at least the eighteenth century, medical ideas and practices concerning the human body were closely connected to philosophy in several ways.

Since ancient times, beginning with both Plato and Aristotle, philosophers used the kind of knowledge necessary for the practice of medicine as an important example of the nature of practical knowledge, in general. For instance, doctors may agree on the cause and symptoms of a disease, but deciding that a certain patient has the disease and what the appropriate course of treatment for that person should be requires making judgments that go beyond the evidence. Such judgments depend heavily on what was done in similar cases in past experience, and that says something important about the nature of practical knowledge. (Aristotle said that because of the importance of the role of experience in medicine, which was not an exact science, it would be wiser to choose an older than a younger doctor.)

In Aristotle’s time there was awareness that medicine had been part of philosophy during the pre-Socratic period. Beginning in the medieval period, especially in Islamic culture, many philosophers had practical training as physicians and were employed as doctors to their patrons. That practice was also common through the Renaissance and early modern period in Europe. Another link between medicine and philosophy is that, as educated thinkers, philosophers have always had ideas about the human body and its functions, which in their scientific aspects have come from the medical views of their times. Philosophers have also maintained an interest in human emotions and thought processes, based on theories developed by psychologists and their predecessors before the science of psychology existed.