MECHANISM, PURPOSE AND AGENCY: the metaphysics of mental causation and free will

Libertarianism is a thesis according to which free will is incompatible with determinism and human agents possess free will to some degree. Three formidable objections have been raised against this thesis by its opponents: (i) Libertarianism requires the falsity of philosophical naturalism or materialist theories of mind; (ii) Indeterminism threatens freedom by undermining the rational, volitional control of agents; (iii) If indeterminism does not threaten our freedom, then neither does it enhance our freedom or add to human agency anything of appreciable value. I address these challenges in novel ways by assessing recent work on mental causation and consciousness and applying that work to the problems at hand, arguing that progress may be made in the free will debate by reorienting it toward an examination of those conditions which are essential to agency simpliciter. In response to (i) I argue that a coherent account of libertarian agency requires no greater an ontological inventory than naturalism allows provided that there is a naturalistic solution to the problem of mental causation, one that (i*) secures the causal efficacy of mentality, (ii*) coheres with the characteristic purposiveness of intentional behavior, and (iii*) illuminates what it is for an agent to produce or bring about an action. I show that (ii) is unfounded on a causal construal of action, since the most promising sets of necessary and sufficient conditions for purposive behavior are adeterministic, and therefore do not require the obtaining of deterministic causal connections between intentions and matching behavior. Since agents exercise the relevant capacities of control just in case they act purposively, it follows that indeterminacy does not in itself vitiate agential control. I analyze the claim expressed in (iii) as a special case of the conceptual gap between the first-person and the third-person perspectives, arguing that the conceptual irreducibility of agential production (iii*), which results from the deployment of phenomenal concepts in our thinking about agency generally, is what lies at the root of the present objection, but that such conceptual irreducibility does not entail that the exercise of genuine free will cannot consist in suitably related indeterministic event causes.