Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-22T04:55:18.419Z Has data issue: false hasContentIssue false
  • English
  • Français

Life is hard: countering definitional pessimism concerning the definition of life

Published online by Cambridge University Press:  16 September 2016

Kelly C. Smith
Kelly C. Smith*
Affiliation:
Departments of Philosophy & Religion and Biological Sciences, Clemson University, Hardin Hall, Clemson, SC 29634, USA
*
e-mail: kcs@clemson.edu
Get access Rights & Permissions [Opens in a new window]

Abstract

Cleland and Chyba published a classic piece in 2002 that began a movement I call definitional pessimism, where it is argued that there is no point in attempting anything like a general definition of life. This paper offers a critical response to the pessimist position in general and the influential arguments offered by Cleland and her collaborators in particular. One such argument is that all definitions of life fall short of an ideal in which necessary and sufficient conditions produce unambiguous categorizations that dispose of all counterexamples. But this concept of definition is controversial within philosophy; a fact that greatly diminishes the force of the admonition that biologists should conform to such an ideal. Moreover, biology may well be fundamentally different from logic and the physical sciences from which this ideal is drawn, to the point where definitional conformity misrepresents biological reality. Another idea often pushed is that the prospects for definitional success concerning life are on a par with medieval alchemy's attempts to define matter – that is, doomed to fail for lack of a unifying scientific theory. But this comparison to alchemy is both historically inaccurate and unfair. Planetary science before the discovery of the first exoplanets offers a much better analogy, with much more optimistic conclusions. The pessimists also make much of the desirability of using microbes as models for any universal concept of life, from which they conclude that certain types of ‘Darwinian’ evolutionary definitions are inadequate. But this argument posits an unrealistic ideal, as no account of life can both be universal and do justice to the sorts of precise causal mechanisms microbes exemplify. The character of biology and the demand for universality in definitions of life thus probably accords better with functional rather than structural categories. The bottom line is that there is simply no viable alternative, either pragmatically or theoretically, to the pursuit of definitions. If nothing else, the empirical data the pessimists demand will be a very long time coming and scientists will of necessity continue to employ definitions of life in the interim. Chastising them for this will only drive their ideas underground where they can escape critical analysis, making the problems caused by problematic conceptions of life worse.

Keywords

alchemyalchymyClelandDarwinismdefinitionlifenatural kindpessimismuniversal biology
Type
Research Article
Information
International Journal of Astrobiology , Volume 15 , Special Issue 4: The history and philosophy of the Origin of Life , October 2016 , pp. 277 - 289
Copyright
Copyright © Cambridge University Press 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Allen, C. & Bekoff, M. (1995). Biological function, adaptation, and natural design. Philos. Sci. 62(4), 609–622.Google Scholar
Bedau, M. (1996). The nature of life. In The Philosophy of Artificial Life, ed. Boden, M., pp. 332–356. Oxford University Press, London.Google Scholar
Bedau, M. & Cleland, C. (2010). The Nature of Life: Classic and Contemporary Perspectives from Philosophy and Science. Cambridge University Press, London.Google Scholar
Boyd, R. (1991). Realism, anti-foundationalism and the enthusiasm for natural kinds. Philos. Stud. 61(1/2), 127–148.Google Scholar
Burtt, E.A. (1925). The Metaphysical Foundations of Modern Physical Science. Trench, Trubner & Company, New York.Google Scholar
Cartwright, N. (1980). The truth doesn't explain much. Amer. Phil. Q. 17(2), 159–163.Google Scholar
Chyba, C.F. & Mcdonald, G.D. (1995). The origins of life in the solar system. Ann. Rev. Earth Planet. Sci. 23, 215–249.Google Scholar
Cleland, C. (forthcoming). The Quest for a Universal Theory of Life. Cambridge University Press, London.Google Scholar
Cleland, C. (2004). Why it is a mistake to define ‘life’. In Artificial Life IX Workshop Proc., ed. Pollack, J., Bedau, M., Husbands, P., Ikegami, T., & Watson, R.A., pp. 93–95. MIT Press, Cambridge, MA.Google Scholar
Cleland, C. (2006). Understanding the nature of life. In Life as We Know It, ed. Seckbach, J., pp. 589–600. Springer, Dordrecht.Google Scholar
Cleland, C. (2007). Epistemological issues in the study of microbial life. Stud. Hist. Phil. Biol. Biomed. Sci. 38, 847–861.Google Scholar
Cleland, C. (2012). Life without definitions. Synthese 185, 125–144.Google Scholar
Cleland, C. (2013a). Is a general theory of life possible? Biol. Philos. 28, 189–204.Google Scholar
Cleland, C. (2013b). Is a general theory of life possible? Biol. Theory 7, 368–379.Google Scholar
Cleland, C. (2013c). Conceptual challenges for contemporary theories of the origin of life. Curr. Org. Chem. 17, 1704–1709.Google Scholar
Cleland, C. & Chyba, C. (2002). Defining ‘life’. Orig. Life Evol. Biosph. 32(4), 387–393.Google Scholar
Cleland, C. & Chyba, C. (2007). Does life have a definition? In Planets and Life: The Emerging Science of Astrobiology, ed. Sullivan, W.T. & Baross, J., pp. 119–131. Cambridge University Press, London.Google Scholar
Cleland, C. & Chyba, C. (2010). Does life have a definition? In The Nature of Life, ed. Bedau, M. & Cleland, C., pp. 326–339. Cambridge University Press, London.Google Scholar
Cleland, C. & Copley, S.D. (2005). The possibility of alternative microbial life on earth. Int. J. Astrobiol. 4, 165–173.Google Scholar
Cleland, C. & Zerella, M. (2013). What is life? In The Philosophy of Biology, ed. Kampourakis, K., pp. 31–48. Springer, Dordrecht.Google Scholar
Cooper, G. (1996). Theoretical modeling and biological laws. Philos. Sci. 63, Supplement, S28–S35.Google Scholar
Davies, P., Benner, S., Cleland, C., Lineweaver, C. & McKay, C. (2009). Signatures of a shadow biosphere. Astrobiology 9, 241–249.Google Scholar
Davis, B. (1993). Analytic chemistry and the ‘big’ scientific instrumentation revolution. Ann. Sci. 50(3), 267–290.Google Scholar
Dembski, W.A. (2002). Eugenie Scott and the NCSE. Theism.net. http://www.theism.net/article/26 (accessed 18 October 2015).Google Scholar
Dick, S.J. (2013). Discovery and Classification in Astronomy. Cambridge University Press, London.Google Scholar
Dieckmann, U. & Doebeli, M. (1999). On the origin of species by sympatric speciation. Nature 400(6742), 354–357.Google Scholar
Donoghue, M.J. (1985). A critique of the biological species concept and recommendations for a phylogenetic alternative. Bryologist 85, 172–181.Google Scholar
Dyson, F. (1985). Origins of Life. Cambridge University Press, London.Google Scholar
Elgin, M. (2006). There may be strict empirical laws in biology after all. Biol. Philos. 21(1), 119–134.Google Scholar
Fleischaker, G.R. (1990). Origins of life: an operational definition. Orig. Life Evol. Biosph. 20, 127–137.Google Scholar
Fors, H. (2015). The Limits of Matter. Chicago University Press, Chicago.Google Scholar
Fry, I. (2000). The Emergence of Life on Earth. Rutgers University Press, New Brunswick.Google Scholar
Gayon, J. (2010). Defining life. Orig. Life Evol. Biosph. 40(2), 231–244.Google Scholar
Ghiselin, M.T. (1987). Species concepts, individuality and objectivity. Biol. Philos. 2(2), 127–143.Google Scholar
Hacking, I. (1991). A tradition of natural kinds. Philos. Stud. 61(1–2), 109–126.Google Scholar
Hempel, C. (1966). Philosophy of Natural Science. Prentice-Hall, Englewood Cliffs.Google Scholar
Ihde, D. (1991). Instrumental Realism. Indiana University Press, Bloomington.Google Scholar
Joyce, J. (1994). Forward. In Origins of Life: The Central Concepts, ed. Deamer, D.W. & Fleischaker, G.R., pp. xi–xii. Jones and Bartlett, Burlington.Google Scholar
Keosian, J. (1974). Life's beginnings – origin or evolution? Orig. Life 5, 285–293.Google Scholar
Klein, H.P. (1978). The viking biological experiments on mars. Icarus 34(3), 666–674.Google Scholar
Machery, E. (2012). Why I stopped worrying about the definition of life. Synthese 185(1), 145–164.Google Scholar
Mayden, R.L. (1997). A hierarchy of species concepts. In Species: The Units of Diversity, ed. Claridge, M.F., Dawah, H.A. & Wilson, M.R., pp. 381–423. Chapman and Hall, London.Google Scholar
Mayr, E. (2000). The biological species concept. In Species Concepts and Phylogenetic Theory: a Debate, ed. Wheeler, Q.D. & Meier, R., pp. 17–29. Columbia University Press, New York.Google Scholar
Mayr, E. (2007). What Makes Biology Unique? Cambridge University Press, London.Google Scholar
McKay, C. (1997). The search for life on Mars. Orig. Evol. Biosph. 27, 263–289.Google Scholar
Mix, L. (2015). Defending definitions of life. Astrobiology 15(1), 15–19.Google Scholar
Myers, P.Z. (2008). Woese, the Darwinian Threshold and Intelligent Design. Panda's Thumb. http://www.pandasthumb.org/archives/2008/03/woese-the-darwi.html (accessed 18 October 2015).Google Scholar
Newman, W.R. & Principe, L.M. (1998). Alchymy versus chemistry. Early Sci. Med. 3(1), 32–65.Google Scholar
Noor, M.A.F. (2002). Is the biological species concept showing its age? Trends Ecol. Evol. 17(4), 153–154.Google Scholar
Pirie, N.W. (1937). The meaningless of the terms life and living. In Perspectives in Biochemistry, ed. Needham, J. & Green, D., pp. 11–22. Cambridge University Press, London.Google Scholar
Putnam, H. (1975). Philosophical Papers, Vol. II. Cambridge University Press, London.Google Scholar
Rasmussen, S.C. (2014). The Quest for Aqua Vitae. Springer, New York.Google Scholar
Rosenberg, A. & McShea, D. (2007). Philosophy of Biology. Routledge, New York.Google Scholar
Ruiz-Mirazo, K., Peretó, J. & Moreno, A. (2010). Defining life or bringing biology to life. Orig. Life Evol. Biosph. 40, 203–213.Google Scholar
Smith, K.C. (2001). Appealing to ignorance behind the cloak of ambiguity. In Intelligent Design Creationism and its Critics, ed. Pennock, R., pp. 705–735. MIT Press, Cambridge.Google Scholar
Smith, K.C. (2015). From notes taken at the Second Conf. on the History and Philosophy of Astrobiology in Hoor, Sweden, 7 May.Google Scholar
Sweetlove, L. (2011). Number of Species on Earth Tagged at 8.7 Million. Nature Online, http://www.nature.com/news/2011/110823/full/news.2011.498.html (accessed 18 October 2015).Google Scholar
Via, S. (2001). Sympatric speciation in animals. Trends Ecol. Evol. 16(7), 381–390.Google Scholar
Winn, J.N. & Fabrycky, D.C. (2015). The occurrence and architecture of exoplanetary systems. Ann. Rev. Astron. Astroph. 53, 409–447.Google Scholar
Wouters, A.G. (2003). Four notions of biological function. Stud. Hist. Philos. Sci. 34(4), 633–668.Google Scholar