Institute of Philosophy
Biological Identity Conference
Rethinking biological identity when concepts of organisms and ecosystems are intertwined
Individuals have an identity; typically, identity in metaphysical terms means two things, the identity through time, and the distinguishability from other individuals. Various conceptions of biological individuality have been proposed, a very attractive one being the individuality defined through evolutionary theory as a unit of selection (as proposed by Hull initially). Yet in the last decade several new visions of biological individuality have been proposed. Some of them emphasize the fact that, because of the role of symbiosis in the construction of organisms of many clades, as well as because of the dynamics in which body parts like cells and tissues are involved (which are often ecological dynamics, such as competition or dispersal processes), organisms share metaphysical properties with ecosystems. To this extent, while metazoan organisms used to be the paradigm of biological individuality and ecosystems seem collections of organisms in some abiotic context, our notions of individuality should be revised if organisms are akin to ecosystems. In turn, what should be the identity of these biological individuals, when ecology is involved in the definition of individuality? An influential thesis about biological individuality (tracing back to Kripke) is “origin essentialism”: the nature of their parent gametes and the timing of their fusion define the transworld identity of individuals (at least for multicellular metazoan organisms). However, such identity is much less easy to be defined if individuals are ecosystems that may sometimes recruit new heterogeneous symbionts (like in the case of many symbioses involving bacteria). This talk will begin by considering the relation between metaphysical concepts of individuality and identity, emphasizing the two aspects of identity (accounting for the persistence in time as the same; accounting for discriminability). Then it will consider the challenges for several classical views of biological individuality (inspired by Hull’s thesis) raised by an ecological understanding of biological individuality. Finally, it will question the notion of biological identity in this context, by criticizing the view of “origin essentialism” and then introducing a formal account of the two aspects of identity that appears plausible in such a perspective.
Recent debates in metaphysics on personal identity and material constitution have seen a rise of theories which appeal to a biological understanding of identity. So-called animalists claim that the puzzles of standard psychological theories of personal identity can be avoided by the insight that we are essentially animals or organisms rather than persons and that the necessary and sufficient conditions of our identity over time therefore are purely biological in character. Moreover, it has been argued (most famously by Peter van Inwagen) that if there are any composite objects at all in the world, then these are those studied by biology. According to this view, there are no inanimate things like stones or cars, strictly speaking, as these turn out to be just collections of particles; but there are living organisms, due to a special unity making them each one rather than many.
It is time to investigate whether, and if so how, the concept of biological identity can indeed serve the functions metaphysicians attribute to it. For that purpose, the conference will aim to confront the metaphysical motives for proposing biological conceptions of identity, diachronic as well as synchronic, with the scientifically informed research on biological identity which has been carried out within the philosophy of biology but which so far has been little noticed by the metaphysics community.