This chapter begins by looking at a very literal form of marks of identity—fingerprints—then examines the obsession of modern societies with issues of identity. While the notion of identity is not new—especially as a philosophical topic—a widespread concern with one's personal identity, and its relations to “the others” among whom one lives, seems to have emerged with greater intensity with the Enlightenment, and to gain force throughout the nineteenth and twentieth centuries, and into modern time. To the extent that a characteristic of modernity is a new valuation of the individual, the obsession with identity follows almost inevitably.