Annals of the History and Philosophy of Biology

Holism, Coherence and the Dispositional Concept of Functions
something like the heart a constituent of an organism. A heart is a constituent of an organism
simply because it is mereologically contained in it. But the heart is a constituent
of a system of capacities that have biological functions solely by virtue of there being a
suitable arrangement of capacities such that many other things emerge as functions, too.
The heart can only have a function (in the sense explicated here) if it has a capacity that
contributes to the circulatory system's capacity to transport solutes and cells, which in
turn contribute to a host of other capacities, and so on. This is what I mean by a coherent
system of capacities. As there might be more than one such coherent system, I have
required that only the system that best explains the organism's capacity to self-reproduce
constitutes its functional organization. The relevant kind of system S, then, is a system of
select capacities, not the organism itself. 7
Thus, I conclude that, on the coherence account, biological functions are holistic
properties in a similar way in which beliefs are (provided that semantic holism is correct).
I would now like to draw a comparison to a form of holism that is instantiated by a version
of the etiological theory of functions.
Peter McLaughlin (2001) has proposed an alternative to the classical etiological account
according to which functional status is attributed on the basis of the contribution
that a function bearer makes to an organism's self-reproduction. By this, McLaughlin
means the maintenance of an organism's identity through time by the continuous replacement
of its parts (I also use the term in this sense here). According to McLaughlin,
something that contributes to self-reproduction in a sense explains its own presence in
the system because it is reproduced along with the whole system to the self-reproduction
of which it contributes. This explaining of a function bearer's presence in the system is
what renders this a species of etiological function.
As McLaughlin notes (2001, p. 210-212), his account leads to a certain kind of holism.
Self-reproduction is an activity that is exerted by the whole organism through continuously
replacing its own parts. This activity explains why a specific function bearer
such as the heart is present in a token organism, and its function is determined by the
contribution it makes to the process of self-reproduction. Now, it seems to me that this
whole notion requires downward causation, a notion that has been shown to be problematic.
8 Thus, the holism that is inherent in McLaughlin's account is a causal holism. By
contrast, the holism of the coherence account of functions that I have outlined here is
not committed to holistic causality; it is a form of metaphysical holism that arises because
of the special relational nature of biological functions. Thus, the coherence account
of functions comes metaphysically less expensive than McLaughlin's version of the
etiological account.
7 One could ask here if it is really desirable to detach an organism's system of functions from the organism
itself? Are these two systems not numerically identical? I think they are not, for the following reason: An
organism's parts contain many capacities that are not functions (e.g., the heart's capacity to make thumping
noises). An organism's system of biological functions supervenes on the causal dispositions of its mereological
parts, but it is not identical with it.
8 See, e.g., Kim (1992), Hoyningen-Huene (1994). McLaughlin does not seem to be sure whether his account
really requires downward causation; sometimes he also speaks of "apparent holism".
Annals of the History and Philosophy of Biology, Vol. 10 (2005)
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