98 The Debate over the Consequence Argument
Vihvelin, Kadri. 2013. “The Abilities and Dispositions of Our Freedom.” In Causes,
Laws, & Free Will: Why Determinism Doesn’t Matter. New York: Oxford University
Press: chapter 6.
Notes
1 A number of philosophers have proposed helpful refinement to the argument, includ-
ing John Fischer, 1986, 1994; Ted Warfield, 2000; David Widerker, 1987; Alicia
Finch 2013; and Carolina Sartorio 2015.
2 We’ll not rehearse the details again here. See our discussion in Section 3.2.
3 What is a “modal proposition”? For readers who might profit from a brief introduc-
tory explanation of this issue, please see the Appendix I at the end of this chapter
before reading further.
4 The notion of power necessity was developed by Carl Ginet (1980, 1983), and
endorsed by John Martin Fischer (1994). In formulating the Consequence Argument,
other philosophers have instead made use of slightly different modalities, such as one
built from the expression, “has no choice about whether.. .” or “... is not up to one” or
“... is unavoidable for one.” These details will not matter for the level of resolution
we bring to the discussion in this chapter.
5 Here we are simplifying by assuming that it is unproblematic to combine power
necessity with respect to the past and power necessity with respect to the laws into a
single premise about power necessity over the past and the laws. Doing so is contro-
versial. To say of power necessity that power necessity over one proposition, p, and
power necessity over a second proposition, q, validly generates power necessity of the
conjunction of p and q, is to say that power necessity has the logical property of
agglomerativity. If power necessity is agglomerative, then the principle (Np&Nq)
strictly implies N(p&q) is valid.
But the property of agglomerativity is slippery and seems not to apply validly to
other modalities, such as obligation. Suppose Joan is obligated by a promise to meet
June at noon for lunch on Thursday. Setting aside the indexing, let us represent her
obligation as O(r). And suppose also that Joan is obligated to be at a doctor’s appoint-
ment at the very same time and in a different place that same Thursday. Let us
represent this as O(s). So, it is accurate to describe Joan’s obligations with the follow-
ing conjunction: O(r) & O(s). But does Joan have a single obligation (O(r&s)) to meet
June for lunch and make her doctor’s appointment, an obligation which it is physic-
ally impossible for her to satisfy, given that she cannot be in two different places at
the same time? It seems not, at least if a constraint on obligation is that it is not phys-
ically impossible to comply with it. (See also the appendix to this chapter, where we
illustrate that logical possibility is also not agglomerative.)
If, like the notion of obligation, power necessity is not agglomerative, then the first
premise of the Consequence Argument as we have formulated it here might be illicit.
Power necessity with regard to the past, and power necessity with regard to the laws
of nature, might not warrant the inference of power necessity with regard to the con-
junction of the past and the laws of nature. If so, then a viable version of the Con-
sequence Argument can only proceed by introducing distinct premises for power
necessity over the laws and power necessity over the past. (Furthermore, if it turns
out, as some critics have argued, that one can derive a commitment to agglomerativity
from the inference principle Transfer, this too might very well create problems.)