[The power of science in Tissot's L'Onanisme]

The Swiss physician Tissot published in 1760 the first edition in French of L'Onanisme, a book which dealt with the diseases caused by masturbation and had a deep and lasting influence. For the first time the problem of masturbation was tackled from a strictly medical angle. Tissot used observation and logical reasoning, and rejected acts of faith. However, behind this fierce rationalism a religious morality was concealed, which was never explicitly expressed but could be guessed through some expressions, in particular through the idea of 'nature'. The latter concept related back to the physical laws, to the moral laws and to the religious laws at the same time. If Tissot's medical discourse had more influence than the preceding religious and moral discourses, it is because of the rationality of its line of argument, which could lead to a real internalization of the message by the reader. Letters to Tissot show indeed that sick people did not see the interdiction of masturbation as coming from an external authority, but as coming from themselves. The power relationship was not any more between two persons, but between the reason and desires of a single individual.