History is familiar with great scientific traditions which have been substantial, effective, cumulative and progressive.* At the level of great eras of civilization, extensive and not episodic phenomena, very ancient Chinese science, Greek science and Arab science are objects of investigation for historical erudition, but also for the scientific historian and the philosopher of sciences. Many of the elements of these systems were the source of “modern science”, as it is called, or are integral parts ol’ this system of knowledge and practice which has been constructed over a little more than three centuries. Diachronically, the “scientific revolution” of the classical age in Europe does not signify a total break with what preceded it: Chinese astronomy, Arab algebra and the hospital organization of the Islamic world were used, even if the ideology of scientists when they wrote their own history, particularly from the 19th century onward, tends to make of modern science a purely European phenomenon.