Professor Sen reminds his audience that identity can be a complicated matter, pointing out that there is, of course, no great problem in convincing oneself that an object is identical with itself; Wittgenstein has even offered the view that 'there is no finer example of a useless proposition'.Professor Sen continues 'yet it is not trivial to ask what relations obtain between an object and itself, other than being identical, and also, how two identical objects relate to each other. When we shift our attention from the notion of being identical to that of sharing an identity, and to theidea of identifying oneself with others of a particular group, which is central to some of the common uses of the idea of identity, the complexity increases further. It is this difficult problem of social identity and its role and implications with which this lecture is concerned'.