I wanted to thank Thomas for allowing me to be the featured author for this month. Throughout the month, I plan on discussing the Direct Argument, the Consequence Argument, how the metaphysics of laws of nature ought to change the free will debate, whether there is an incompatibilist account of the ability to do otherwise, and how the standard account explaining the apparent directionality of time ought to change the free will debate. While I hope to cover a wide range of topics, each of these discussions stem from a common theme. In this post, I will explore the general concern that gives rise to the posts I shall be making throughout the month.
Much of the free will literature looks odd from the perspective of a smart undergraduate student. Frequently, however, they learn to speak the language the free will debate is carried out in and those of us immersed in it long enough tend to lose track of why the debate initially seemed strange. Nevertheless, perhaps the debate goes wrong precisely where we teach students not to worry. Perhaps the free will debate can be improved by taking seriously those areas that initially seem strange instead of learning to ignore the oddity.
To see why much of the free will literature looks odd when first encountered, consider how we typically define determinism. A world is deterministic if and only if a complete description of the events that occur at some moment in time combined with the laws of nature entail all true propositions. Notice, however, that entailment is a semantic notion. P entails Q if and only if it is not possible for P to be true and Q to be false. Yet, we must also restrict P and Q to only those sorts of things that can have truth values. After all, it is not possible for my left shoe to be true and my right shoe to be false. Yet, my left shoe does not entail my right shoe. Entailment is a relationship between the bearers of truth. So, if the laws of nature entail anything, laws of nature must be propositions or sentences. Yet, nobody has ever been constrained by a proposition. Propositions do not cause anything to occur. Similarly, on this definition, determinism is not about relationships between the events that occur in a world. Instead, determinism is about relationships between descriptions of these events.
A similar concern can be seen when we think of where we attribute moral responsibility in arguments like the Direct Argument. In the Direct Argument, we transfer a lack of responsibility for the truth of a proposition to a lack of responsibility for the truth of any proposition that it entails. Yet, we never praise of blame an agent for the truth vale of a proposition. People are responsible for what they do and the states of affairs that they bring about, not directly for descriptions of the world. We act in the world, not on the semantic plane. We might blame Sally for killing Kate. We might even blame Sally for making the proposition "Kate was killed" true. We do not, however blame Sally for the proposition "Kate was killed" being true. It seems that it is a category mistake to attach responsibility to propositions instead of to those things that make the proposition true. Responsibility is attached to acts and events in the world and not directly to propositions or descriptions of the world.
Prior to Kripke's work it was quite common for philosophers to slide between metaphysical, epistemic, and semantic claims. After all, it was commonly believed that all necessary truths are also a priori and analytic. Kripke's demonstration that there are necessary truths that are only a posteriori knowable provided one of the first clues that sliding between semantic, epistemic, and ontological concepts can be troubling.
More importantly, theorists in the truthmaker literature have recently reached a consensus (something rare among philosophers) that truthmaking does not follow classical entailment. (Rodriguez-Pereyra 2006, p. 187). While there have been many objections to the claim that truthmaking is preserved through classical entailment, I only have space to consider one of the earliest criticisms here. Consider the explosion problem for necessary truths (Restall, 1996). Suppose that truthmaking were preserved through classical logic. In that case, if o is a truthmaker for P, and P classically entails Q, then o is a truthmaker for Q. Clearly, this post makes it true that 'this post exists.' Yet, since necessarily true propositions are entailed by any proposition, 'this post exists' classically entails that '2+2=4'. If we assume that truthmaking is preserved under classical entailment, it follows that this post makes it true that 2+2=4. Yet, clearly, this post does not make it the case that 2+2=4, so we have excellent reason to believe that truthmaking is not preserved through classical entailment.
If the logic of truthmaking is distinct from classical entailment, and classical entailment is the appropriate logic for semantic issues, then we have even greater reasons to be leery when discussions of metaphysical topics like free will and moral responsibility are addressed as if they were debates about propositions and entailment relations. Given how extensively semantic ascent is employed in the free will literature, this problem seems like it ought to have significant ramifications for the free will debate. After all, the very definition of determinism that is most frequently employed in the free will literature ought to be enough to provide reason to think that something has gone fundamentally wrong in the debate.
The reason that so much of the free will debate is carried out in its current manner is that much of the contemporary free will debate took its current shape when the linguistic turn was still quite popular. During the linguistic turn, it was thought that we could avoid difficult metaphysical questions by replacing them with questions about semantics. Free will is one of the most challenging philosophical topics because so many other areas of philosophy bear on what we ought to think about free will. If we could bracket these difficult topics through the process of semantic ascent, the free will debate becomes significantly easier. It would be nice if we could ignore what laws of nature are and instead merely focus on propositions about laws of nature when considering free will. Yet, the failure of the linguistic turn, lessons we learned from Kripke, and the contemporary truthmakers literature coming to the conclusion that the appropriate logic for semantic concerns is not the same as the appropriate logic for ontological concerns all ought to make us deeply suspect of this change in topic.
I am convinced that incompatibilism about moral responsibility and incompatibilism about the ability to do otherwise both gain a significant amount of their appeal through an illicit use of semantic ascent. If I am right, much of the contemporary free will debate needs to be radically revised.
Restall, G., 1996, “Truth-makers, Entailment and Necessity,” Australasian Journal of
Philosophy, 74: 331–340.
Rodriguez-Pereyra, G. (2006). Truthmakers. Philosophy Compass, 1, 186–200.
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