The object of this article is to examine various situations where lying, on the part of doctors and on the part of patients, can be seen, not in order to make a moral judgement of this practice but to analyse what is socially put into play when it takes place. We will show what links and what distinguishes the notions of secret, concealment and lying, and we will see that these differences are often more differences of degree than of nature. It will be demonstrated that lying is a constituent part of the doctor - patient relationship, both a means and a sign of the power that each party derives from this relationship and that lying is in direct relation to the social role that each one has to perform; and that this activity, as rational as it may seem in the sense that it has its 'reasons', sociological and/or therapeutic, is none the less paradoxical with regards to other logic which subtends the behaviour and the choices of actors
