The phenomena of the uprooting of identities that have been induced by processes of globalisation make it urgent to reappraise what is actually meant by the notions of identity and difference, of both individuals and groups. The traditional approach to the topic has typically been excessively schematic and simplistic in its attitude to these categories: the very theories of multi-culturalism that are so much in vogue these days seem to reveal a decidedly static, durable conception of identity and otherness. The aim of this essay is to analyse the contribution made by recent anthropological and sociological studies (Amselle, Wieviorka, Hannerz, Clifford) to today’s philoso-phical, political and legal debate. These studies highlight how the affirmation of com-plete identities does not stand up to the ceaseless nature of global links, where there is a tendency to produce differences continuously rather than reproduce them. The metaphor of interbreeding, of the cultural hybrid of these links, thus appears to consti-tute an obligatory milestone towards any understanding of complex, ambivalent phe-nomena that defy all attempts at formal classification and definition.