Our societies receive and reproduce differences, but they invent it, including under the seal of the tradition. Each of us, in the most immediate circle of acquaintances, is confronted with the raid of new identities, even with conversions; we observe the development of cultural movements. We also notice that our own experiences of a cultural sense of identity, including the most stable seemingly, are not inevitably definitive, that personal changes are always possible, susceptible to lead us up to the pure and simple renunciation of an identity, to adopt if necessary a piece of news. In the...