Synthese

, Volume 185, Issue 1, pp 125–144

Life without definitions

Article

Abstract

The question ‘what is life?’ has long been a source of philosophical debate and in recent years has taken on increasing scientific importance. The most popular approach among both philosophers and scientists for answering this question is to provide a “definition” of life. In this article I explore a variety of different definitional approaches, both traditional and non-traditional, that have been used to “define” life. I argue that all of them are deeply flawed. It is my contention that a scientifically compelling understanding of the nature of life presupposes an empirically adequate scientific theory (vs. definition) of life; as I argue, scientific theories are not the sort of thing that can be encapsulated in definitions. Unfortunately, as I also discuss, scientists are currently in no position to formulate even a tentative version of such a theory. Recent discoveries in biology and biochemistry have revealed that familiar Earth life represents a single example that may not be representative of life. If this is the case, life on Earth today provides an empirically inadequate foundation for theorizing about life considered generally. I sketch a strategy for procuring the needed additional examples of life without the guidance of a definition or theory of life, and close with an application to NASA’s fledgling search for extraterrestrial life.

Keywords

Life Definition Theory Theoretical identity Natural kinds Anomalies 

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References

  1. Ainsworth G. C. (1976) Introduction to the history of mycology. Cambridge University Press, CambridgeGoogle Scholar
  2. Bedau M. A. (1998) Four puzzles about life. Artificial Life 4: 125–140CrossRefGoogle Scholar
  3. Benner S. A. (1994) Expanding the genetic lexicon: Incorporating non-standard amino acids into proteins by ribosome-based synthesis. Trends in Biotechnology 12: 158–163CrossRefGoogle Scholar
  4. Benner S. A., Ricardo A., Carrigan M. A. (2004) Is there a common chemical model for life in the universe?. Current Opinion in Chemical Biology 8: 672–689CrossRefGoogle Scholar
  5. Boyd R. (1999a) Homeostasis, species, and higher taxa. In: Wilson R. (ed.) Species: New interdisciplinary essays. Cambridge University Press, Cambridge, pp 141–185Google Scholar
  6. Boyd R. (1999b) Kinds, complexity and multiple realization. Philosophical Studies 95: 67–98CrossRefGoogle Scholar
  7. Chalmers D. J., Jackson F. (2001) Conceptual analysis and reductive explanation. The Philosophical Review 110: 315–360CrossRefGoogle Scholar
  8. Cleland C. E. (2006) Understanding the nature of life: A matter of definition or theory?. In: Seckbach J. (ed.) Life as we know it. Springer, Dordrecht, pp 589–600Google Scholar
  9. Cleland C. E. (2007) Epistemological issues in the study of microbial life: Alternative terran biospheres?. Studies in History and Philosophy of Biological and Biomedical Sciences 38: 847–861Google Scholar
  10. Cleland C. E., Chyba C. F. (2002) Defining ‘life’. Origins of Life and Evolution of the Biosphere 32: 387–393CrossRefGoogle Scholar
  11. Cleland C. E., Chyba C. F. (2007) Does ‘life’ have a definition?. In: Sullivan W. T., Baross J. A. (eds) Planets and life. Cambridge University Press, Cambridge, pp 119–131Google Scholar
  12. Cleland C. E., Copley S. D. (2005) The possibility of alternative microbial life on earth. International Journal of Astrobiology 2: 165–173Google Scholar
  13. Davies P. C. W., Lineweaver C. H. (2005) Finding a second sample of life on earth. Astrobiology 5: 154–163CrossRefGoogle Scholar
  14. Dupré J. (1993) The disorder of things. Harvard University Press, CambridgeGoogle Scholar
  15. Jakosky B. M., Westall F., Brack A. (2007) Mars. In: Sullivan W. T., Baross J. A. (eds) Planets and life. Cambridge University Press, Cambridge, pp 357–387Google Scholar
  16. Joyce, G. F. (1995). The RNA world: Life before DNA and protein. In B. Zuckerman & M. Hart (Eds.), Extraterrestrials—where are they? (Vol. II, pp. 139–151). Cambridge: Cambridge University Press.Google Scholar
  17. Keller E. F. (2002) Making sense of life. Harvard University Press, Cambridge, pp 284–294Google Scholar
  18. Klein H. P. (1978) The Viking biological experiments on Mars. Icarus 34: 666–674CrossRefGoogle Scholar
  19. Kripke S. (1972) Naming and necessity. Harvard University Press, CambridgeGoogle Scholar
  20. Kuhn T. (1962) The structure of scientific revolutions. University of Chicago Press, ChicagoGoogle Scholar
  21. Lange M. (1995) Life, ‘artificial life,’ and scientific explanation. Philosophy of Science 63: 225–244CrossRefGoogle Scholar
  22. Lavoisier, A. L. (1783). On the nature of water and on experiments which appear to prove that this substance is not strictly speaking an element but that it is susceptible of decomposition and recomposition. Observations sur la Physique, 23, 452–455 (trans. Carmen Giunta. http://webserver.lemoyne.edu/faculty/giunta/laveau.html).
  23. Locke J. (1689) An Essay Concerning Human Understanding. Oxford University Press, OxfordGoogle Scholar
  24. Mellor C. H. (1977) Natural kinds. British Journal for the Philosophy of Science 28: 299–312CrossRefGoogle Scholar
  25. Needham P. (2002) discovery that water is H2O. International Studies in the Philosophy of Science 15: 205–226CrossRefGoogle Scholar
  26. Putnam, H. (1975). The meaning of ‘meaning’. In K. Gunderson (Ed.), Language, mind and knowledge: Minnesota studies in the philosophy of science (Vol. VII, pp. 131–193). Minneapolis, MN: Minnesota University Press.Google Scholar
  27. Psillos S. (1999) Scientific realism: How science tracks truth. Routledge, LondonGoogle Scholar
  28. Roberts G. (1994) The mirror of alchemy. University of Toronto Press, TorontoGoogle Scholar
  29. Ruiz-Mirazo K., Pereto A., Moreno J. (2002) A universal definition of life: Autonomy and open-ended evolution. Origins of Life and Evolution of the Biosphere 34: 323–346CrossRefGoogle Scholar
  30. Ward P. D., Brownlee D. (2000) Rare Earth. Copernicus, New YorkGoogle Scholar
  31. Woese C. R. (2004) The archaeal concept and the world it lives in: A retrospective. Photosynthesis Research 80: 371–372CrossRefGoogle Scholar
  32. Zemach E. M. (1976) Putnam’s theory on the reference of substance terms. The Journal of Philosophy LXXIIII: 116–126CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Department of Philosophy, Center for AstrobiologyUniversity of ColoradoBoulderUSA

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