A Modal Theory of Function
Bence Nánay · The Journal of Philosophy · 2010
he function of a trait token is usually defined in terms of some properties of other (past, present, or future) tokens of the same trait type.I argue that this strategy is problematic, as trait types are (at least partly) individuated by their functional properties, which would lead to circularity.In order to avoid this problem, I suggest a way to define the function of a trait token in terms of the properties of the very same trait token.To able to allow for the possibility of malfunctioning, some of these properties need to be modal ones: a function of a trait is to do F just in case its doing F would contribute to the inclusive fitness of the organism whose trait it is.Function attributions have modal force.Finally, I explore whether and how this theory of biological function could be modified to cover artifact function.i. artifact function and biological function The function of my corkscrew is to open bottles.The function of my heart is to pump blood.These two function-attributions are of different kinds.My corkscrew is an artifact, whereas my heart is a biological organ.Artifact function seems to be the easier of the two kinds to analyze.The standard way of explaining artifact function is with reference to the notion of design.My corkscrew has the function to open wine bottles if and only if it was designed to open wine bottles.If we wonder what the function of an artifact may be, we should just ask the designer to get an answer.This explanatory scheme will not work in the case of biological functions, as there is no designer who designed biological traits (or, in any case, there is no one we could ask).Thus, it seems that in spite of the fact that we talk about functions both in the artifact and in the biological case, these two kinds of function are very different indeed: one is fixed by design, whereas the other is not.I focus on biological function in this paper, but at the end I will come back to the notion of artifact function and reevaluate the * I presented earlier versions of this paper at the Pacific APA in March 2006 as well as at the University of British Columbia (April 2006) and at Syracuse University (November 2006).I am grateful to my commentator at the APA, Robert Richardson.I am especially grateful to Mohan Matthen,