The Debate over the Consequence Argument 91LMC provides a credible semantics for such ability claims, or maybe there is a
plausible semantics for this sort of ability that instead denies the Fixity of
the Past.
But at the same time, such ability claims may reflect only general sorts of
abilities. And as Randolph Clarke (2009) has argued, the issue between the com-
patibilist and the incompatibilist may be whether determinism is compatible with
an agent’s exercise of such a general ability on a particular occasion. The incom-
patibilist can, after all, readily allow that there are general abilities, such as the
ability to speak French in the above example, which one retains at the time one
is not exercising it. But she may not grant that a causally determined agent could
in fact have exercised such a general ability at a time when he does not in fact
do so.
A conclusion one might draw is that there may be a more specific and
stronger notion of an ability to do otherwise that is not compatibilism- friendly,
and that can’t be accounted for by semantics that deny the Fixity of the Past or
the Fixity of the Laws. Carl Ginet (1990: chapter 5) has argued that there is
reason to think that there are contexts of inference in which we assume such a
more specific and stronger notion of an ability to do otherwise, which on his
view cannot be accounted for by any such compatibilist semantic proposal.^22 If
he is right, the answer to the question: Is being able to do otherwise compatible
with determinism? depends on which sense you mean.
A key question now arises: Which notion of “could have done otherwise,” if
any, is required for moral responsibility in the sense at issue in the debate? In
effect, Ginet proposes to settle this question by a manipulation argument wherein
an agent is manipulated to act in a certain way but still would satisfy the com-
patibilist sense of “able to do otherwise.” This is a valuable suggestion, and it’s
the one we’ll turn to in Chapter 7.
Appendix I: What is a Modal Proposition?
What is a modal proposition? Introductory students are bound to find most dis-
cussions of the Consequence Argument technically inaccessible, especially as
regards formal notions involving modal propositions and the logical properties
of them. A few brief remarks should prove helpful. A modal proposition is about
a way (a manner or a mode) in which another proposition obtains. Logical neces-
sity is a modal notion. Consider the unmodalized proposition p:
p = Two plus two equals four.That proposition, p, is true. But notice that there is a way—a manner or
mode—in which p is true. It is true and cannot be but true, hence, we can append
to this proposition the modal operator, it is necessary that, and we generate a
distinct proposition which has the original embedded in it:
□p = It is necessary that two plus two equals four.