Ronald De Sousa

In both biology and psychology, the notion of an individual is indispensable yet puzzling. It has played a variety of roles in diverse contexts, ranging from philosophical problems of personal identity to scientific questions about the immunological mechanisms for telling ‘self’ from ‘non-self.’ There are notorious cases in which the question of individuality is difficult to settle — ant hill, slime mold, or beehive, for instance. Yet the notion of an individual organism, both dependent on and independent of other individuals in specific ways, is crucial to our conception of life itself. It is also crucial to our notion of mentality, and hence to other concepts — moral and social — which must be explicated in terms of individual mentality. (Think, for example, of the importance of the quality and nature of individual consciousness to debates about abortion and euthanasia.)

Existentialism is compatible with a broadly biological vision of who we are. This thesis is grounded in an analysis of “concrete” or “individual” possibility, which differs from standard conceptions of possibility in that it allows for possibilities to come into being or disappear through time. Concrete possibilities are introduced both in individual life and by major transitions in evolution. In particular, the advent of ultrasociality and of language has enabled human goals to be formulated in partial independence from the vestigial “goal” of biological replication. The existentialist stance is validated by the necessity of choice grounded in emotion, in a way that does not require a commitment to a Kantian Will