It is clear that Galen's medicine is first and foremost a rational type of medicine, based on the supremacy and value of his method. Galen dedicated a major work, in fourteen books, to the fundamental principles of this method: On the Therapeutic Method (MM) (Kühn X. 1–1021). At the same time, the story of his life and autobiographical anecdotes play an exceptional part in Galen's work. This point has been noted, as the combination of scientific and autobiographical writing remains highly original in medical literature. However, as far as I know, the extent of the linkage between the methodological objectives of Galen, the physician, and the autobiographical project of Galen, the writer, has never been fully brought out. I am, however, deeply convinced not only that there is a strong and unbreakable link between bios and methodos (life and method) in Galen's work, but also that he sees this link as having a particularly important part to play in the acquisition of every kind of knowledge. That is to say, the bios–methodos combination undoubtedly lies at the heart of the world of knowledge to which ancient medicine so powerfully contributed. In late antiquity, Galenic medicine was at the forefront of Greek literature: it maintained very close and original ties with other disciplines such as history, rhetoric and philosophy, and made a truly major contribution to the construction of the world of learning.