Introduction: The Definition of Life

In this special issue of BioCosmos, we address the problem of the definition of life. If we assume that biology is a genuine science, with its own distinctive subject matter, then there must be a real distinction between living and non-living things. We are concerned not merely with the meaning of the word ‘life’ or with merely clarifying our biological concepts, but with uncovering what it is (if anything) in the world that unifies the domain of living things and separates it from the rest of the cosmos. Six distinguished philosophers have contributed their answers to this problem.