There is no generally-accepted definition of ‘Life’ and consensus to a definition is difficult. Thus, different definitions are given:

  • Life is a self-sustaining chemical system capable of Darwinian evolution” (NASA)


Analysis of the numerous definitions are given in:
Edward N. Trifonov (2011) Vocabulary of Definitions of Life Suggests a Definition, Journal of Biomolecular Structure and Dynamics, 29:2, 259-266, DOI:10.1080/073911011010524992 (link: