Free Will, Moral Responsibility, Determinism 231.6. Indeterminism, Mechanism, and Naturalism
We close this chapter with a brief set of comments about a collection of related
issues. As we explained above (Section 1.4), indeterminism is just the denial of
determinism. On one characterization, indeterminism is true just in case, at
some time, there is more than one future that is physically possible. As we
explained, for those who contend that indeterminism is required for free will, it
is not enough that determinism is false. The indeterministic breaks must be suit-
ably located in the unfolding history of the world in a way that corresponds
with potential moments for free action. Recall that the world Wi wasn’t a deter-
ministic world but did not have indeterministic relations between events at
points that would matter for free action. Moreover, not only must actions have
indeterministic causes suitably located, the indeterminism must be of a certain
sort. This point is often expressed in connection with claims about the indeter-
minism that some think may occur at the quantum level. On this suggestion, our
universe is not deterministic but, at the most fundamental level, indeterministic,
and the laws governing the natural order at this level are probabilistic or statisti-
cal laws. Nevertheless, so the worry goes, the indeterminacy does not allow for
macro- level variation of the sort that would involve, say, a person standing up
rather than remaining seated, as might be involved in the free act of standing
rather than sitting. For the most part, the thought is, the micro- indeterminacies
“cancel each other out,” and we get macro- level determinism. Hence, what
physics may suggest is something like “near- determinism” or “almost-
determinism.” But for indeterminism to make a difference for free will, it would
need to be sufficiently substantial at the macro- level for it to matter to exercises
of free will.
Another issue has to do with a shift in focus away from determinism to a
wider thesis, mechanism. Suppose it turns out that quantum mechanics discon-
firms the strict thesis of determinism as narrowly characterized above. Some phi-
losophers maintain that mechanism would appear to pose the same threat to free
will as has been traditionally posed by determinism. According to these philoso-
phers, the apparent tension between determinism and free will, and the various
theoretical positions one can take on resolving that tension, are entirely pre-
served when mechanism is at issue and not the more precise (and less plausible)
theory of determinism. Consider Hilary Bok’s expression of the view, wherein
she quotes Daniel Dennett:
Mechanism is the view that human actions can be explained as the result of
natural processes alone; that the “mechanistic style of explanation, which
works so well for electrons, motors, and galaxies,” also works well for us. If
mechanism is true, then just as our explanations of the motions of the
planets no longer requires the existence of prime movers to supplement
natural processes, so our actions could in principle be explained by a
complex neurophysiological theory, without reference to a nonnatural self
that causes them. (Bok, 1998: 3, quoting Dennett, 1981: 233)