Abstract

The general question of biological identity has two main aspects, uniqueness (what makes each living thing unique?), and individuality (what ensures that a living thing remain “itself” while constantly changing?). Contemporary immunology, dominated by the concepts of self and nonself, considers these two questions as its province. An important task is to assess this assertion. This chapter defines the two questions of uniqueness and individuality, and explains how immunologists claim to respond them. It emphasizes the necessity to define more precisely the notions of self and nonself, and to articulate the immunological perspective on biological uniqueness and individuality with other biological perspectives, in particular the evolutionary one.