Douglas Ehring

Various philosophical accounts of function attributions have taken the following form:fis a function of a structureXin a systemSif and only ifXdoesfinSandfcausally contributes toG. While sharing this form, these accounts disagree over how “G” is to be specified. Specifications of “G” range from the fairly determinate to the less determinate. Although much of the debate over functions has been concerned with the proper characterization of “G”, it has become apparent that theories which fit this schema are subject to now-standard counterexamples in whichfdoes in fact causally contribute to the realization ofG, butffails to be a function ofXin thatf's contribution is accidental in nature. Consider, for example, goal-state theory according to whichfis a function ofXinSjust in casefcontributes to the realization of some goal ofS. Imagine that Jones has a silver dollar in his shirt pocket which deflects a bullet meant for his chest. Assuming that the coin is in Jones's pocket for reasons unrelated to his goal of continued existence, although the coin contributes to this goal, it does not have the function of “bullet deflector” since its contribution is merely accidental. We can easily generate similar counter-examples for other theories which fit this schema but differ in how “G” is specified. I will call this the problem of “accidentalG-generating effects”. Counterexamples of this type have put pressure on theorists to modify this schema or at least to add additional conditions in order to rule out “accidental functions”. In this paper I will first examine various modifications which have been suggested for avoiding this type of counterexample, and then develop a new approach to the question of “accidental functions”.

Wesley Salmon has developed a theory of causation which makes use of the concepts of a "causal process" and a "causal interaction." Roughly, a causal process is a process which transmits its own structure, and a causal interaction is an intersection of processes which transforms the character of these processes. The cause-effect relation is analyzed as a causal interaction followed by a causal process which terminates in a further causal interaction. In this paper I present a series of problem cases which run "counter" to Salmon's account.