The history of identity, internalism and externalism in the biological sciences

Many consider that twentieth century biology has been dominated by an internalist perspective (Lewontin 2000; Oyama 2000; Minelli 2003; Robert 2004), in particular the fields of developmental biology, genetics and immunology. The debate between internalism and externalism is actually not limited to biology as such; it also appears, for instance, in the psychological sciences, in particular in the debate between nativismand empiricism (Godfrey-Smith 1996).

These debates in biology and psychology are deeply rooted in philosophical debates about the maintaining of individual identity through time as well as about the acquisition of knowledge by the human mind, as paradigmatically illustrated by the oppositionbetween Locke (1979) and Leibniz (1996). Of course, from philosophy to biology and psychology, “internalism” and “externalism”are two extreme positions, and a continuum of theses exists between the two.

This IDEM sub-project will aim at elucidating the historical and philosophical roots of the on-going debate between internalism and externalism by putting it into the context of philosophical analyses on the construction of identity through time, and at offering a clear picture of how this debate is still alive today at the intersection of developmental biology, immunology and microbiology.

It will thus address the following questions:

  • How has diachronic identity been conceived in philosophy?
  • How have the respective roles of “internal” and “external” factors in an ever-changing identity through time been conceived, in particular in the founding debate between “empiricism” and “rationalism”?
  • In addition, can recent debates on endurancevs, perdurance (Lewis 1986), four-dimensionalism (Sider 2001) or the thing-process distinction (Dupré 2012) be useful to better characterize biological identity?
  • What is the nature of the current debate over internalism and externalism in the biological sciences? In particular, many suggest that today’s developmental biology is still strongly internalist: what do they exactly mean? Is this claim true? Has not the relative decline ofthe idea of a “genetic program” in the last twenty years led to a softening of internalism?
  • Many so-called “interactionist” claims have recently been suggested; do they constitute legitimate alternatives to traditional internalism/externalism debates, or, as Oyama (2000) has claimed,do they simply hide the crux of the problemthanks to an all-too-easy label?

These investigations about identity in philosophy and the internalism/externalism debate in the life sciences will then be confronted with the case study that makes the specificity of the IDEM project, through the question: How can research on the role of the microbiota in the construction of the organismimpact the internalism-externalism debate?

The main issue will be to determine whether the “ecological-developmental perspective” (Gilbert and Epel 2009) in biology constitutes a new framework likely to deeply re-orient the debate, or rather a simple resurgence of externalism. Key proponents of this perspective (Oyama 2000; Gilbert and Epel 2009) reject the“externalism” label, and defend instead a form of strongly intertwined interactionism, or a “co-constructionism”, according to which the organism and its environment constantly build each other, so much so that distinguishing “internal” and “external” causes would often be vain (Lewontin 2000;Oyama 2000; Sterelny 2005). The assessment of this “co-constructionism” will be an important component of this sub-project.


Dupré, J. (2012). Processes of Life. New York, Oxford University Press

Gilbert, S. F., and Epel, D. (2009). Ecological Developmental Biology. Sunderland, Sinauer Associates

Godfrey-Smith, P. (1996). Complexity and the Function of Mind in Nature. Cambridge, Cambridge University Press

Leibniz, G. W. [1765] 1996. New Essays on Human Understanding. Translated andedited by P. Remnant and J. Bennett. Cambridge,Cambridge University Press

Lewis, D. (1986). On the Plurality of Worlds.Oxford, Basil Blackwell

Lewontin, R. C. (2000). The Triple Helix. Cambridge, MA, Harvard University Press.

Locke, J. [1690] (1979). An Essay Concerning Human Understanding. Edited byP. H. Nidditch. Oxford: Clarendon Press & New York: Oxford UniversityPress.

Minelli, A. (2003). The Development of Animal Form. Cambridge University Press, Cambridge

Oyama, S. (2000 [1985]). The Ontogeny of Information: Developmental Systems and Evolution. Duke University Press, Durham, N.C

Robert, J.S. (2004). Embryology, Epigenesis and Evolution: Taking Development Seriously. Cambridge,Cambridge University Press

Sider, T. (2001). Four-dimensionalism: An Ontology of Persistence and Time.Oxford,Oxford University Press

Sterelny, K. (2005). Made by each other: organisms and theirenvironment. Biology &Philosophy20, 21-36