ography of science: An analysis based on Kuhn's writings 132 of the one who first enunciated it. One names: the theorems of Apollonius, the principle of Huygens. But, except some curious scholars, who then wants to carry out some research into the one who bears that name? When and where did he live? Who was he? By what sequences of meditations and essays did he come to know that truth for which he had not been entirely forgotten? These are questions that we never imagine to ask, that we do not suffer at all by seeing them unanswered (Duhem 1912, I). Duhem places himself in a distinct position from that which prevailed in the traditional history of science. He insists on presenting a different view, according to which the historical analysis of a discovery or scientific creation is fairly complex because there is no way to establish an exact moment of its occurrence, to indicate a single name as being responsible for it, without incurring injustice and inaccuracy. "No scientific discovery is a creation ex nihilo", says Duhem (1912, III), and if that is truth, then we have to explore a singularly extended domain whenever we wish to retrace the history of a discovery. It will not be enough (it's quite the opposite, actually) to meditate on the writings of the one to whom that discovery is commonly attributed. We have to search, read, compare the books of all those who, more or less directly, have been the auxiliaries of that person: the precursors who had prepared the new idea; the collaborators who assisted the inventor; the opponents who forced him to define, clarify and consolidate his thoughts; the successors who highlighted the latent fertility of this thought. We will have to review those of whom our author has spoken, those with whom he spoke and those who spoke of him (Duhem 1912, VIII). Today, Duhem's insistence upon this question may seem exaggerated, but it is important to note the context in which he puts his argumentation. As indicated by Kuhn (1977, 106), the oldest traditions of history of science had