Biological Identity

Perspectives from Metaphysics and the Philosophy of Biology

Anne Sophie Meincke, John Dupré, Anne Sophie Meincke, John Dupré

• Publisher: Taylor & Francis
• Year: 2020
• Print ISBN: 9780367495039
• eBook ISBN: 9781351066365
• Edition: 1
• Topic: Philosophy
• Subtopic: Cell Biology

Analytic metaphysics has recently discovered biology as a means of grounding metaphysical theories. This has resulted in long-standing metaphysical puzzles, such as the problems of personal identity and material constitution, being increasingly addressed by appeal to a biological understanding of identity. This development within metaphysics is in significant tension with the growing tendency amongst philosophers of biology to regard biological identity as a deep puzzle in its own right, especially following recent advances in our understanding of symbiosis, the evolution of multi-cellular organisms and the inherently dynamical character of living systems. Moreover, and building on these biological insights, the broadly substance ontological framework of metaphysical theories of biological identity appears problematic to a growing number of philosophers of biology who invoke process ontology instead.

This volume addresses this tension, exploring to what extent it can be dissolved. For this purpose, the volume presents the first selection of essays exclusively focused on biological identity and written by experts in metaphysics, the philosophy of biology and biology. The resulting cross-disciplinary dialogue paves the way for a convincing account of biological identity that is both metaphysically constructive and scientifically informed, and will be of interest to metaphysicians, philosophers of biology and theoretical biologists.

1 Biological identity

Why metaphysicians and philosophers of biology should talk to one another

Anne Sophie Meincke and John Dupré

1.1 Biological identity in metaphysics and in the philosophy of biology

Our world seems populated by individual things that keep their identity over time. The car in which I will soon go home is the same that brought me to the office in the morning. The pebble which lies on the windowsill in my kitchen is the one which I collected at the seaside yesterday, and the rubber plant next to it was some years ago given to me as a birthday present. I also have not the slightest doubt that the dog happily welcoming me now is the same dog that I left alone at home a few hours earlier. And, not least, I am pretty sure that I myself was the very same person on all the various occasions just mentioned.

However, as so often in philosophy, what seems natural and straightforward at first glance, turns out on closer consideration to raise a host of problems. Am I really the same as, say, ten years ago? Have I not changed quite a lot since then? At any rate, I have aged; and the same is sadly true for my car which is at risk of failing the upcoming MOT test. How is it possible to stay the same while changing? What does it take for persons and cars to persist through time? Is persistence tantamount to numerical identity or to some weaker relation, say, relations of continuity? And if the latter, relations between what? As has famously been noted in discussions of identity, self-identity is not a relation between two things, but a necessary truth about one thing. But then, once we move away from strict self-identity, exactly how much continuity is needed for identity through time and how are we to handle hypothetical branching cases? Philosophers are a long way from agreeing on how to answer these questions. In fact, the debate on personal identity in analytic metaphysics is (in)famous for its notoriously aporetic character, and the corresponding debate about the persistence criteria of artefacts fares no better – just think of puzzles such as that of the ship of Theseus which already baffled the ancient Greeks.

Remarkably, an increasing number of metaphysicians currently express their confidence that the difficulties abate, or even vanish, when it comes to biological beings. So-called animalists suggest that key obstacles faced by standard psychological theories of personal identity can be avoided once it is acknowledged that we are animals or organisms, i.e., that the necessary and sufficient conditions of our identity over time are biological – either purely (Olson 1997, Snowdon 2014) or at least in part (Wiggins 2001). Instead of personal identity, the animalists maintain, we should focus on biological identity. This tendency towards a biological approach within the personal identity debate (see also Blatti and Snowdon 2016) is echoed by a parallel development in the metaphysical debate on the constitution of material objects. Peter van Inwagen (1990) has famously argued that inanimate things like pebbles or cars do not exist. In metaphysical terms, he argues, they turn out to be mere collections of particles, which is to say, not things or objects at all. If indeed any composite things exist, so the claim goes, then these are living organisms – such as my rubber plant and myself – due to the strong unity of biological life which makes each organism precisely one rather than many.

The metaphysical appeal to biological identity, which contrasts with the wide-spread scepticism among metaphysicians concerning personal identity and artefact identity, looks less surprising when we consider the broader intellectual context in which it is situated, the current revival of Aristotelian metaphysics. Opposing the empiricist-cum-linguistic orientation of large parts of contemporary metaphysics, a growing number of metaphysicians advocate a return to an a priori approach to metaphysics together with a commitment to Aristotelian concepts, such as substance, essence or potentiality, as real aspects – or “categories” – of being (Wiggins 1980, 2001, Lowe 2001, 2002, 2006, Oderberg 2007, Tahko 2012, Groff and Greco 2013, Novotný and Novák 2014). As is well known, Aristotle argued for the ontological priority of substances, i.e., of composite but individual particular things, over both simple particular things (“atoms”) and universal abstract things or concepts (“universals”, Platonic “ideas” or “forms”).¹ Interestingly, this incorporates the view that living things – organisms – are the paradigmatic cases of substances (Moya 2000, Cohen 2002, chapter 5), whereas Aristotle remained ambivalent with respect to the question of whether artefacts possess the status of substances (see Katayama 1999 for a detailed analysis). These doctrines revolve around Aristotle’s theory of hylomorphic unity according to which physical objects are compounds of matter (ὕλη) and form (μορφή), and they continue to influence contemporary metaphysical views of biological identity even where the reference to Aristotle is loose and superficial (as in van Inwagen 1990 and Olson 1997).

Nonetheless, the (re-)discovery of biological identity in contemporary metaphysics, and the optimism associated with it, remains astonishing from the perspective of another philosophical discipline, the philosophy of biology. As it happens, recent years have seen a lively debate in the philosophy of biology on biological identity – biological individuality with respect to both its synchronic and its diachronic dimension² – which has brought to light the numerous and intricate problems associated with the interpretation and application of this concept (see, e.g., Clarke 2010, 2013, Pradeu 2012, 2016, Bouchard and Huneman 2013, Ereshefsky and Pedroso 2016, Fagan 2016, Godfrey-Smith 2016, Guay and Pradeu 2016b, Haber 2016, Lidgard and Nyhart 2017, Paternotte 2016, Wilson and Barker 2019).³ As a result, philosophers of biology are far from considering biological identity as a miracle cure for identity puzzles, typically regarding it rather as a puzzle in its own right. Two recent developments in biology that have been much discussed by philosophers of biology are mainly responsible for this.

First, studies in symbiosis and the evolution of multi-cellular organisms undermine the belief in the organism as a homogeneous, strongly unified unit that is strictly demarcated from its environment. Organisms, it begins to appear, are rather ultimately heterogeneous assemblies of diverse units tied together by varying degrees of cooperation into a more or less stable constellation with fuzzy and fluctuating boundaries (Dupré and O’Malley 2009, Queller and Strassmann 2009, Dupré 2010) – they are so-called holobionts (Margulis 1991, Gilbert, Sapp and Tauber 2012, Bordenstein and Theis 2015, Gilbert and Tauber 2016, Queller and Strassmann 2016, Skillings 2016) and, in the case of eusocial organisms, arguably also superorganisms (Wilson and Sober 1989, Hölldobler and Wilson 2009). At the same time, it is far from clear that individual organisms, if there are any, are the relevant units upon which evolution acts, rather than genes, genomes, cells, groups, species or perhaps all of these (Dawkins 1976, Wilson and Sober 1994, Okasha 2006, Godfrey-Smith 2009; see Lloyd 2017a for an informative overview of the discussion). In particular the hypothesis that natural selection operates at the level of the holobiont (Zilber-Rosenberg and Rosenberg 2008, Doolittle and Booth 2017, Gilbert, Rosenberg, and Zilber-Rosenberg 2017, Lloyd 2017b, Suárez 2018), or even at the level of the superorganism (Wilson and Sober 1989, Folse and Roughgarden 2010, Haber 2013), is complemented and amplified by the recent appreciation of the frequency and evolutionary importance of epigenetic inheritance, developmental plasticity and niche construction (Odling-Smee, Laland and Feldman 2003, Fusco and Minelli 2010, Gilbert 2014, Chiu and Gilbert 2015, Jablonka 2017).⁴

Second, an important strand of systems biology, even while still relying on the concept of an individual organism,⁵ stresses the dynamical and environment-dependent character of organisms (Alberghina and Westerhoff 2005, Noble 2006, 2017, Boogerd et al. 2007). Organisms are described as complex hierarchies of biological processes interacting with each other and with environmental processes so as to keep the system as a whole in a far-from-equilibrium state. Accordingly, if there is such a thing as the identity of biological dynamical systems, this reveals itself to be a hard-won achievement, constantly constituted and maintained by the system itself, specifically by maintaining a controlled exchange of matter and energy with the environment. It therefore comes as no surprise that some philosophers of biology, including the editors of this volume, have called for abandoning underlying traditional substance metaphysical conceptions in favour of a new process metaphysical framework regarded as more suitable for the description and understanding of biological phenomena and possibly of reality in general (Bickhard 2011, Dupré 2012, 2017, Jaeger and Monk 2015, Nicholson and Dupré 2018, Meincke 2018, 2019a, 2019b). This process ontological turn in the philosophy of biology is accompanied by a rising awareness of the role scientific practices – qua processes of individuation – play in conceptualising identity and individuality in biology as well as in other sciences (Bueno, Chen and Fagan 2018), followed by calls for a pluralistic stance on individuation and individuality (Dupré 2018, Kaiser 2018, Love 2018 and Waters 2018 (all in Bueno, Chen and Fagan 2018)).

Comparing the perspectives on biological identity in metaphysics and the philosophy of biology, we thus find a striking tension: while Aristotle-inspired metaphysicians tend to be confident that biological identity is a robust part of reality on which we can rely to solve long-standing metaphysical problems such as those of personal identity and material constitution, philosophers of biology, engaging with the latest research in biology, have unveiled the manifold and intricate challenges for a satisfying account of biological identity – challenges that may well make one wonder if there is such a thing as biological identity at all. One may ask, at least, whether there is any unique, objectively given kind of biological identity, or rather various kinds of continuities in the living nexus that may be picked out and employed for particular purposes, an idea that one of us has referred to as “promiscuous individualism” (Dupré 2012, p. 241). At the very least, the existence of competing catalogues of criteria of biological identity, together with the lack of consensus among philosophers of biology as to what the phenomena are to which the respective criteria of biological identity can be applied, indicates the immense difficulty of the task of providing a unified concept of biological identity in the light of recent scientific discoveries. From the point of view of the philosophy of biology, we can no longer appeal to any unproblematic notion of biological identity.

1.2 Why metaphysicians and philosophers of biology should talk to one another

One of the two main aims of the present volume is to investigate whether the tension between the metaphysicians’ views of biological identity and those of the philosophers of biology can be resolved. Are we entitled to a realist view of biological identity? And if so, how does such a realist view relate to empirical facts about biological entities revealed by today’s biology? We believe that any metaphysical theory of biological identity, if it is to be convincing, must pay attention to the relevant body of scientific knowledge. At the same time, we are strongly aware of the fact that both actual biological research and its accompanying philosophical reflection in the philosophy of biology are shaped and guided by metaphysical presumptions.⁶ Thus, exactly the difficulties philosophers of biology have with conceptualising biological identity point, we think, towards fundamental metaphysical questions which need to be explicated and reflected upon. The conclusion we draw from this is that a dialogue is needed across the boundaries of these disciplines. Metaphysicians and philosophers of biology must talk to one another in order to better understand biological identity.

The present volume initiates such a cross-disciplinary dialogue on the subject of biological identity, by bringing together contributions from experts in metaphysics, the philosophy of biology and theoretical biology. As a matter of fact, so far the debates on biological identity in metaphysics and in the philosophy of biology have happened largely in isolation from one another. There has not been much exchang...

Table of contents

• Cover
• Half Title
• Series Page
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• List of figures
• List of contributors
• Series editor’s foreword
• Foreword
• Acknowledgements
• 1 Biological identity: why metaphysicians and philosophers of biology should talk to one another
• 2 Siphonophores: a metaphysical case study
• 3 Biological individuals as “weak individuals” and their identity: exploring a radical hypothesis in the metaphysics of science
• 4 What is the problem of biological individuality?
• 5 The role of individuality in the origin of life
• 6 The being of living beings: foundationalist materialism versus hylomorphism
• 7 The origins and evolution of animal identity
• 8 Processes within processes: a dynamic account of living beings and its implications for understanding the human individual
• 9 Activity, process, continuant, substance, organism
• 10 Diachronic identity in complex life cycles: an organisational perspective
• 11 Pregnancy and biological identity
• 12 Processual individuals and moral responsibility
• 13 The nature of persons and the nature of animals
• 14 Processual animalism: towards a scientifically informed theory of personal identity
• Index