Friday, April 25, 2014
The autonomous organism
The philosopher of biology, Ernst Myer, famously argued that biology is an autonomous science. He meant by that not that biology had a distinct set of principles from physics and chemistry (for example) but that it had additional principles that could not be derived from those more basic sciences.
This claim will stand or fall, I think, on a distinct but much more exciting claim: that autonomy is essential to understanding what a living organism really is. Biology is the study of living organisms. It is proved remarkably difficult to what those two key terms‑life and organism‑mean. Since an organism is composed of the same physical constituents as non-living matter, so that if you break down the animal into organs and the organs into cells and the cells into subcellular molecular mechanisms, eventually you come to something that is dead rather than alive, what does it mean to say that the organism is alive?
John Dupré § and Maureen A. O’Malley [“Varieties of Living Things: Life at the Intersection of Lineage and Metabolism” (Philos Theor Biol (2009) 1:e003))] put the matter this way:
In this paper we shall highlight a tension in standard discussions of characteristics of life, which tend to prioritize one or other of two fundamental but very different features of living things: the capacity to form lineages by replication and the capacity to exist as metabolically self-sustaining wholes. We suggest that this tension can best be resolved by seeing life as something that arises only at the intersection of these two features: matter is living when lineages are involved – directly or indirectly – in metabolic processes.
Dupré and O’Malley distinguish two “fundamental but very different features of living things”. One is the tendency of living things to form lineages. The word tendency is necessary because, obviously, many living things fail to reproduce and many lines of descent reach dead ends. On the other hand, every actually organism that actually exists or has ever existed at any time is the latest in an unbroken line of successful breeders.
The other fundamental feature of living things is “the capacity to exist as metabolically self-sustaining wholes”. Organisms are wholes, which is to say that they are composed of distinct parts which operate to some degree independently of one another; yet the operation of the parts is somehow controlled by the whole. Dupré and O’Malley argue that the dilemma‑which is it: lineages or self-sustaining wholes?‑can best be answered “yes.” Living organisms are self-sustaining wholes that form lineages and lineages are unbroken lines of self-sustaining wholes.
This strikes me as dead spot on, but what exactly is a “self-sustaining whole”?
Kepa Ruiz-Mirazo and Alvaro Moreno [“Autonomy in evolution: from minimal to complex life” Synthese 1 Feb 2011] argue that autonomy is the main concept that is necessary to understand “the traditional Cartesian gap between the physical and cognitive domains,” as well as “the nature of the organization of individual living entities” and that “autonomy is also fundamental to explaining major evolutionary transitions.” That’s a tall order for one concept, but perhaps this Platonic idea is up to the task.
I can scarcely do justice to this fascinating paper, but let this be my short summary. Living organisms are autonomous in so far as they maintain themselves by resisting both external and internal forces, swimming, as it were, this way and that but always a bit against the current. The organism thus extends itself between the boundaries of inside and outside, self and other. The organisms lays down a law for itself and struggles to be law abiding.
I submit that this may tie together the most basic, metaphysical meaning of autonomy, with the moral and political meanings.
Autonomy may initially appear too heavy a word to be part of a general definition of life. Originally used in the context of law and sociology (in the sense of self government, from the Greek polis) or human cognition and rationality (in the sense of a cognitive agent that acts according to rationally self-generated rules, cf. Kant), for many it will sound like a high-level concept, with too many non-strictly-biological connotations.
Broadly speaking, autonomy is understood as the capacity to act according to self-determined principles. It might also mean that a given ontological or phenomenological level is relatively independent with respect to others, because it is ruled by its own norms (Moreno et al. 2008). However, the idea of autonomy can adopt a more specific, minimal sense [“basic autonomy,” as we have called it (Ruiz-Mirazo and Moreno 2000, 2004)] related to the capacity of a system to self-define, to construct its own identity.
It is in this more basic sense that autonomy proves relevant for the definition of life, since it provides the necessary explanatory power to account for the complex material organization underlying any living organism; namely, its metabolism
That ties together everything I want to talk about in my paper on autonomy.