the beach that had been trodden by our footsteps is now sleeping under deep water: during the relentless oscillations of water back and forth, the Ocean tide has really gone up (Duhem 1894b, 125).37 Concluding Remarks Duhem has been looked upon as one of the founding fathers or ancestors of twentieth-century history and philosophy of science in France. My thesis is that Duhem accomplished an intellectual stream that had emerged considerably earlier. The awareness of the complexity of scientific practice and scientific tradition can be found in some historical and philosophical studies from Cournot to Duhem through Naville and Tannery. They had analysed the superposition of cyclic and linear processes, and the persistence of structural continuities throughout scientific transformations. Cournot, Boussinesq, and Duhem put forward bold mathematisations of new research fields such as economic processes, physical and chemical instabilities, and thermodynamics of irreversible processes. Cournot, Tannery, and Duhem attempted to cast light on the plurality of scientific methods and their histories. Suspicious of every rigid philosophical system, they were in search of a third way between scepticism and dogmatism. The dissemination of Cournot, Naville, Tannery, and then Duhem and Milhaud's researches in the history and philosophy of science contributed to the professionalisation of the field in the French context, and the establishment of a research tradition that is known as historical epistemology.38 Duhem always mentioned the scientists who had contributed to the development of his research field, and put forward a historical reconstruction of those researches. On the contrary, in his historical and philosophical papers we do not find explicit references to previous researches. The fact is that his interests in history and philosophy of science stemmed from his practice in theoretical physics rather than from the study of previous literature. Duhem was objectively in debt to Cournot and other scholars, but a direct inf