1. Introduction
Vihvelin (Reference Vihvelin and Zalta2008, Reference Vihvelin2011, Reference Vihvelin, Hawthorne, Sider and Zimmerman2013) argues that the standard taxonomy of free-will views mischaracterizes incompatibilism and the relationship between incompatibilism and impossibilism. As a result, the standard taxonomy obscures the argumentative burdens of compatibilists and incompatibilists. She argues that her preferred taxonomy, the ‘Three-fold Classification’ (3-FC), offers superior characterizations of these free-will views and the logical relationships that they bear to one another. She uses 3-FC to frame the overview of ‘arguments for incompatibilism’ she gives in her Stanford Encyclopedia of Philosophy entry (Reference Vihvelin2011). Vihvelin also uses her arguments for 3-FC in her latest book – Causes, Laws, and Free Will: Why Determinism Doesn’t Matter (Reference Vihvelin, Hawthorne, Sider and Zimmerman2013) – to motivate her controversial view of the (relatively light) dialectic burdens carried by defenders of compatibilism. Although Vihvelin is right to call for a more adequate taxonomy of free-will views, I contend that Vihvelin’s taxonomy should be rejected: 3-FC is not an improvement over the standard taxonomy and it introduces new problems of its own.
This essay begins, in Section 2, with a brief overview of 3-FC. In the next two sections, I explain why Vihvelin is right to conclude that the standard taxonomy is flawed, but argue that 3-FC is also untenable. Vihvelin’s criticisms of the standard taxonomy of free-will views rest squarely on her preferred understanding of incompatibilism. According to Vihvelin, incompatibilists embrace a specific explanatory thesis, roughly: no one can perform a free action in a deterministic universe because such laws undermine or pose some sort of threat to free will. Yet, as I explain in Section 3, no such explanatory thesis is mentioned in Vihvelin’s own formal definition of ‘incompatibilism’ – which is to say that Vihvelin’s own arguments imply that 3-FC mischaracterizes incompatibilism. More significantly, I argue in Section 4 that Vihvelin’s primary arguments for 3-FC are unsound. Vihvelin’s basic mistake, I contend, is that she conflates questions about the (in)compossibility of free will and deterministic laws with questions about the (in)compatibility of these phenomena. To ask whether free will and deterministic laws are incompossible is simply to ask whether it is metaphysically possible for these phenomena to coexist or co-obtain. By contrast, to ask whether the phenomena are incompatible is to ask whether deterministic laws undermine free will, that is, whether such laws account for the incompossibility of these phenomena.Footnote 1 As a result, Vihvelin’s taxonomy does not explicitly distinguish between (in)compossibility and (in)compatibility views – a major shortcoming, given that each set of views plays an important role in the free-will debate.
I close by explaining how the problems with (Vihvelin’s arguments for) 3-FC cast doubt on the legitimacy of her views about the dialectical burdens on compatibilists and incompatibilists. Still, Vihvelin’s work helps to bring out the serious shortcomings of the standard taxonomy and suggests that philosophers should be suspect of standard characterizations of even the most familiar arguments in the contemporary free-will debate. So, even though 3-FC ultimately fails, Vihvelin’s taxonomical work pushes the debate forward from an interesting new angle.
2. A review of the 3-FC
Central to 3-FC is Vihvelin’s preferred version of the free-will thesis:
The Free-will Thesis: At least one (non-godlike) creature has free will (Reference Vihvelin and Zalta2008, 304, Reference Vihvelin2011).
By ‘non-godlike’, Vihvelin means ‘a creature who is not infinite, omniscient, omnipotent, the cause of its own existence, and so on’ (Reference Vihvelin, Hawthorne, Sider and Zimmerman2013, 24). She uses the term ‘impossibilism’ to name the view that the free-will thesis is necessarily false, that is, the view that it is metaphysically impossible for a free (non-godlike) agent to exist (Reference Vihvelin and Zalta2008, 303). For ease of reference, let us introduce the term ‘possibilism’ to name the contradictory of impossibilism. Possibilism, then, is, the view that metaphysically possibly, at least one non-godlike creature has free will.Footnote 2
‘Compatibilism’, Vihvelin says, ‘is the claim that possibly, determinism and the free will thesis are both true’ (Reference Vihvelin and Zalta2008, 305, Reference Vihvelin2011).Footnote 3 Vihvelin contends that this standard characterization of compatibilism is ‘unproblematic’ (Reference Vihvelin2011), emphasizing that this definition allows the compatibilist to be agnostic about the truth of determinism at the actual world. However, Vihvelin rejects the standard formal definition of ‘incompatibilism’, according to which incompatibilism is simply the negative view that compatibilism is false, saying:
Suppose, as some philosophers have argued, that we lack free will because free will is conceptually or metaphysically impossible, at least for non-godlike creatures like us (C.D. Broad Reference Broad1934; G. Strawson Reference Strawson and Craig1986, Reference Strawson1994, Reference Pereboom2002). If these philosophers are right, there are no free will worlds [i.e. no possible worlds at which the free-will thesis is true]. And if there are no free will worlds, it follows that there are no deterministic free will worlds [i.e. no possible worlds at which both the free-will thesis and determinism are true]. So if free will is conceptually or metaphysically impossible, at least for creatures like us, it follows that incompatibilism (as we have just defined it [as the view that necessarily, if determinism is true, then the free-will thesis is false]) is true. But this does n’t seem right. If it is conceptually or metaphysically impossible for us to have free will, then we lack free will regardless of whether determinism is true or false. And if that is so, then the incompatibilist cannot say the kind of things she has traditionally wanted to say: that the truth or falsity of determinism is relevant to the question of whether or not we have free will, that if determinism were true, then we would lack free will because determinism is true, and so on. (2011; emphasis in original)
Vihvelin makes several key points in this passage: (1) incompatibilism is not merely the view that compatibilism is false; (2) impossibilism entails the negation of compatibilism, but does not entail incompatibilism; and (3) incompatibilism and impossibilism are inconsistent views. Let us consider these points in turn.
In defense of her first point, Vihvelin rightly distinguishes between two anti-compatibilist views. First, she discusses the contradictory of compatibilism, that is, the negative view that there is no possible world at which the conjunction of determinism and the free-will thesis is true. Vihvelin then denies that incompatibilism is merely this negative view. According to Vihvelin, incompatibilists have also ‘traditionally wanted to say’ something positive about why no one acts freely in a universe with deterministic laws. That is, Vihvelin holds that incompatibilists are also committed to the positive thesis that the truth of determinism is relevant to (e.g., partly explains, accounts for, or grounds) the falsity of the free-will thesis at all possible worlds at which determinism is true. Since the mere negation of compatibilism does not entail any such positive thesis, Vihvelin concludes that the negation of compatibilism does not entail incompatibilism. Granting Vihvelin’s claim that incompatibilism is a positive, explanatory view, Vihvelin is right that incompatibilism is not merely the view that compatibilism is false.
Vihvelin says little to justify her claim that there has been a ‘traditional’ worry that deterministic physical laws pose a threat to free will, but one could easily mount evidence in defense of this claim – even if there would be ample room to debate precisely how old this worry is.Footnote 4 Arguably, though, Vihvelin is nonetheless mistaken when she claims that incompatibilists have traditionally had this worry. The term ‘incompatibilist’ is relatively new, having been first used in print by Keith Lehrer in his (1960) dissertation, and later popularized by Peter van Inwagen.Footnote 5 As ‘incompatibilist’ is used by Lehrer and van Inwagen, the incompatibilist is (roughly) someone who holds that necessarily, if determinism is true, then the free-will thesis is false; the incompatibilist contends that it is impossible for the conjunction of these two theses to be true. As a technical matter, then, the term ‘incompatibilist’ was originally defined to name the proponents of a particular negative thesis; the term was not, pace Vihvelin, introduced to pick out adherents of the historically popular view that deterministic laws preclude free will. Against the background of these etymological details, one might argue that Vihvelin is wrong to deny that incompatibilism is the contradictory of compatibilism.
Rather than engage in a debate over how the terms ‘incompatibilist’ and ‘incompatibilism’ are best used in the context of the free-will debate, I will grant Vihvelin her preferred use of the terms. That is, I grant that a defining tenet of incompatibilism is the positive, explanatory thesis that necessarily, if deterministic laws obtain, then no non-godlike being acts freely (at least in part) because deterministic laws obtain. [Or, second-order language, the incompatibilist holds that necessarily, if determinism were true, then the free-will thesis would be false (at least in part) because determinism is true.] In order to stave off confusion, I will hereafter use the term ‘incompossibilism’ to name the negative, nonexplanatory view that deterministic laws and free will cannot possibly co-obtain, that is, the two are incompossible. So characterized, incompatibilism entails incompossibilism but not vice versa. Put another way, incompossibilism is incompatibilism’s negative thesis. Notably, impossibilism also logically entails incompossibilism. So, all impossibilists, qua being impossibilists, endorse incompatibilism’s negative thesis. However, impossibilism does not entail incompatibilism’s positive thesis that deterministic laws pose some sort of threat to free will. As such, incompatibilists cannot coherently deny – though impossibilists and incompossibilists may – that the truth of determinism is relevant to the truth of the free-will thesis.Footnote 6 Assuming Vihvelin’s characterizations of incompatibilism and impossibilism, Vihvelin’s second point is also right: impossibilism does not entail incompatibilism.
However, Vihvelin’s third point, that one cannot consistently endorse both incompatibilism and impossibilism, seems to be mistaken. Vihvelin claims that the impossibilist ‘cannot say the kind of things she has traditionally wanted to say, ’ by which she seems to mean that all impossibilists are committed to the view that whether or not determinism is true (i.e., whether the natural laws are deterministic or indeterministic) is never relevant to – never makes a difference with respect to – whether the free-will thesis is true (i.e., whether free agents exist). Let us call the aforementioned view ‘irrelevantism’ and its adherents ‘irrelevantists’. In other words, irrelevantists hold that it is impossible for someone to lack free will even in part because of the natural laws of that being’s universe. Vihvelin points to G. Strawson’s Basic Argument (Strawson Reference Strawson and Craig1986, Reference Strawson1994, Reference Pereboom2002) as a paradigmatic defense of impossibilism, and it seems that Vihvelin is right to say that proponents of this particular argument for impossibilism are committed to irrelevantism.Footnote 7 Roughly, the Basic Argument defends the view that one could be free (and ultimately moral responsible) only if one could be a causa sui, but such radical self-creation is metaphysically impossible. As G. Strawson explains, ‘there has to be, and cannot be, a starting point in the series of acts of bringing it about that one has a certain nature; a starting point that constitutes an act of ultimate self-origination’ ([Reference Strawson1998] 2011; my emphasis). However, the natural laws that govern the evolution of someone S’s universe – whether deterministic or indeterministic – do not make it the case or otherwise account for the fact that S is not a causa sui at any time t at which S exists. That is, there is no possible person S who lacks free will because of or in virtue of the laws of nature that obtain in S’s universe. It seems, then, that Vihvelin is right to say that proponents of the Basic Argument cannot say, as incompatibilists traditionally have, that if the laws are deterministic then we are not free because the laws are deterministic (or that the free will thesis is false because determinism is true). However, the fact that some arguments for impossibilism are not arguments for incompatibilism falls short of establishing the truth of Vihvelin’s claim that impossibilists cannot endorse incompatibilism.Footnote 8
In her recent book, Vihvelin fleshes out her arguments for the view that impossibilists cannot be incompatibilists. Vihvelin supports this claim through a discussion of the answers that impossibilists and incompatibilist give to the following two questions:
1. Is it possible that non-godlike creatures like us have free will?
2. Is it possible that [non-godlike creatures like us have free will and X is true]? (Reference Vihvelin, Hawthorne, Sider and Zimmerman2013, 25)
According to Vihvelin, the impossibilist (by definition) answers ‘no’ to the first question, what she calls the ‘Possibility Question’. Vihvelin contends that questions of the second sort do not arise for the impossibilist: a negative answer to every instance of the second question follows a fortiori from the impossibilist’s negative answer to the Possibility Question.
As noted earlier, Vihvelin is clearly right that impossibilism entails the view that free will and deterministic laws are incompossible. In other words, the impossibilist’s negative answer to the Possibility Question entails a negative reply to the question that is of interest to incompatibilists, what Vihvelin calls ‘the Determinism question:’
2*The Determinism Question: Is it possible both that we [non-godlike beings] have free will and that determinism is true? (Reference Vihvelin, Hawthorne, Sider and Zimmerman2013, 25).Footnote 9
According to Vihvelin, a negative answer to the Possibility Question entails a negative answer to question 2*. As Vihvelin sees things, the Determinism Question 2* is an open question only for those philosophers who give a positive, possibilist reply to the Possibility Question. The idea seems to be that there is no logical space for a debate over the compossibility of free will and deterministic laws after it has been settled that having free will is metaphysically impossible. Based on these considerations, Vihvelin draws the conclusion that we must reject the coherence of incompatibilist-impossibilism.
Having concluded that incompatibilist–impossibilism is incoherent, Vihvelin arrives at her own preferred definition of ‘incompatibilism’: ‘Incompatibilism is the thesis that there are free will worlds but no deterministic world is a free will world’ (Reference Vihvelin2011). In other words, Vihvelin defines ‘incompatibilism’ as the conjunction of possibilism and the negation of compatibilism (as she characterizes these views). Since possibilism is, by definition, the contradictory of impossibilism, it follows from Vihvelin’s definition of ‘incompatibilism’ that (1) impossibilism does not entail incompatibilism and (2) there is no logical space for incompatibilist–impossibilists. In sum, 3-FC presents compatibilism and incompatibilism as mere contraries and incompatibilist–impossibilism as incoherent.
3. A critique of Vihvelin’s formal definition of ‘incompatibilism’
Hitherto, the most significant critique of 3-FC is that forwarded by Michael McKenna. McKenna agrees with Vihvelin that the original formal definition of ‘incompatibilism’ is too broad, saying ‘As I understand it, incompatibilism is simply the thesis that, at any world at which determinism is true (and there exist non-godlike creatures like ourselves), owing to determinism, there is no free will’ (Reference McKenna2010, 432). McKenna, though, contends that Vihvelin’s proposed definition of ‘incompatibilism’ is too narrow: any adequate definition would leave logical space for one to endorse both traditional incompatibilism and impossibilism. To make his point, McKenna describes a philosopher who endorses impossibilism on the grounds that deterministic and indeterministic laws each present a unique threat to free will (Reference McKenna2010, 433). According to McKenna, one may coherently hold that there are some possible worlds at which no one has free will precisely because deterministic laws obtain, and there are other possible worlds at which we have no free will precisely because indeterministic laws obtain. If McKenna is right, then incompatibilist–impossibilism is, contrary to what Vihvelin tells us, a coherent view.
The problem with McKenna’s story of the incompatibilist–impossibilist is that it does not directly respond to Vihvelin’s arguments for excluding incompatibilist–impossibilism from her taxonomy of free-will views. If Vihvelin’s arguments are sound, then McKenna’s purported counterexample fails – its coherence is merely apparent. In order to upset 3-FC, then, let us address two major problems with the main argument that Vihvelin gives in defense of her definition of ‘incompatibilism’ and her claim that philosophers cannot endorse both incompatibilism and impossibilism.
First, Vihvelin conflates two importantly different ‘determinism questions’ in the course of defending her claim that possibilism is a defining tenet of incompatibilism. Recall that Vihvelin’s Determinism Question (2* above) asks: ‘Is it possible both that we [non-godlike beings] have free will and that determinism is true?’ Yet, Vihvelin describes her Determinism Question as ‘a question about the threat that determinism poses’ or whether deterministic laws would ‘deprive us of the free will we think we have’ (Reference Vihvelin, Hawthorne, Sider and Zimmerman2013, 24; my emphasis). Clearly, Vihvelin’s description of her Determinism Question is wrong. To ask whether deterministic laws threaten, deprive, or undermine our free will is to ask whether the former makes it the case that the latter does not exist. However, Vihvelin’s Determinism Question asks only about the (in)compossibility of free will and deterministic laws; it does not ask whether deterministic laws threaten or deprive anyone of free will.
Let us tease apart the two ‘determinism’ questions that Vihvelin has run together:
3. The (In)compossibility Question: Is it possible both that some [non-godlike beings] have free will and that deterministic laws obtain?
4. The (In)compatibility Question: Is it impossible both that some [non-godlike beings] have free will and that deterministic laws obtain because deterministic laws undermine free will?
The (In)compossibility Question is a restatement of Vihvelin’s Determinism Question (2* above).Footnote 10 Clearly, impossibilism entails a negative answer to the (In)compossibility Question – and to all substitution instances of the more general (in)compossibility question: Is it possible both that some [non-godlike beings] have free will and that X obtains? However, it is not clear that impossibilism entails a negative answer to the (In)compatibility Question, nor is it clear that explanatory questions of this general kind simply do not arise for the impossibilist.
One might argue that explanatory questions such as the (In)compatibility Question do not arise for impossibilists because impossibilist must hold that the concept of free will is incoherent. Assuming the concept of free will is incoherent, one can easily argue that any answer to a question such as the (In)compatibility Determinism Question would be either meaningless or necessarily false. However, Vihvelin does not assume or defend this controversial view while making her case for 3-FC. Rather, Vihvelin says that the impossibilist may claim that free will is metaphysically impossible ‘…either because she thinks that our concept of free will is incoherent or because she thinks that free will is incompatible with some necessarily true proposition’ (Reference Vihvelin and Zalta2008, 303; my emphasis).Footnote 11
With that in mind, consider a philosopher who believes (1) that necessarily, if deterministic laws obtain, then no one has free will because deterministic laws undermine free will, and (2) that necessarily, the natural laws are deterministic (because he is a law necessitarian, say). This philosopher endorses the unique explanatory thesis that Vihvelin attributes to incompatibilists, and he also holds that the antecedent of this conditional is a necessarily true. That is, he thinks that the free-will thesis is necessarily false because it is logically inconsistent with a necessarily true proposition, namely, the proposition expressed by the thesis of determinism. It seems, then, that a philosopher might coherently endorse impossibilism on incompatibilist grounds.Footnote 12 Put another way, it seems that a philosopher might give a negative answer to Vihvelin’s Possibility Question partly because he gives a positive answer to the explanatory (In)compatibility Question. So, contrary to what Vihvelin claims, it seems that explanatory questions such as the (In)compatibility Question can and do arise for impossibilists.
The second and more glaring problem with Vihvelin’s formal definition of ‘incompatibilism’ is illuminated by Vihvelin’s own preferred informal characterization of incompatibilism. As discussed above, Vihvelin argues against the standard characterization of incompatibilism by pointing out that the incompatibilist has traditionally said that ‘if determinism were true, then we would lack free will because determinism is true’ (Reference Vihvelin2011). Yet, in her proposed formal definition, Vihvelin defines ‘incompatibilism’ as ‘the claim that there are Free Will worlds (impossibilism is false), but no Free Will world is a deterministic world; the only Free Will worlds are indeterministic worlds’ (Reference Vihvelin, Hawthorne, Sider and Zimmerman2013, 27; see also 2011). The conjunction of the proposition that free will is metaphysically possible and the proposition that free will is incompossible with deterministic laws does not logically entail any particular explanation of the truth of incompossibilism or impossibilism. In short, if we should reject the standard formal definition of ‘incompatibilism’ because it fails to capture the historically popular view that deterministic laws pose a threat to free will, then we should reject Vihvelin’s formal definition of ‘incompatibilism’ for the very same reason.Footnote 13
4. 3-FC is an impoverished taxonomy
Vihvelin’s informal characterization of incompatibilism reveals that the standard taxonomy is woefully incomplete. After all, there are arguments in the literature – for example, Derk Pereboom’s Four-case Argument (Pereboom Reference Pereboom2001, 110–117) – that pinpoint deterministic laws as a threat to free will.Footnote 14 However, this positive, explanatory thesis is not explicitly identified or uniquely named in the standard taxonomy. Notably, though, important free-will views are also missing from 3-FC.
As noted above, Lehrer introduced the term ‘incompatibilism’ to name (roughly) a negative, non-explanatory thesis: necessarily, if determinism is true, then the free-will thesis is false. Taking the liberty of translating this definition of ‘incompatibilism’ into first-order language, the term was coined to refer to the view that free will does not exist at any possible universe at which deterministic laws obtain. Or, in my preferred terminology, ‘incompatibilism’ was originally used to refer to incompossibilism. Notably, there are famous ‘arguments for incompatibilism’ that conclude to incompossibilism but not the thesis that deterministic laws undermine free will – the latest version of Mele’s Zygote Argument (Reference Mele2013, 176) is a clear example.Footnote 15 Perhaps because Vihvelin sets her sights on correcting or supplanting the original definition of ‘incompatibilism’ with one that better reflects the historically common worry that deterministic laws pose a threat to free will, she overlooks that incompossibilism should also have its own place in a taxonomy of basic free-will views.
Up to this point, I have used ‘compatibilism’ as Vihvelin defines the term – that is, as the term is defined in the standard taxonomy. However, having drawn the distinction between positive incompatibility views and negative incompossibility views helps us to see problems with Vihvelin’s proposed definition of ‘compatibilism’. Recall that Vihvelin defines ‘compatibilism’ along standard lines, using it to name the view that possibly, the conjunction of determinism and the free-will thesis is true. In first-order language, then, compatibilism is the view that it is metaphysically possible for someone (who is non-godlike) to perform a free action. What Vihvelin fails to notice is that this compossibility view is logically consistent with the view that there is some possible world at which deterministic laws undermine free will. Indeed, as Vihvelin characterizes it, compatibilism may be true and yet it may also be true that in some possible deterministic universe U, the deterministic laws of nature undermine the free will of actor A yet do not undermine the free will of A’s identical twin, A *. This reveals that Vihvelin’s characterization of compatibilism fails to express the principled claim usually associated with compatibilism, namely the thesis that deterministic laws pose no threat whatsoever to free will. Indeed, it is difficult to see how one might mount a compelling defense of the compossibility of free action and deterministic laws without defending the principled claim that deterministic laws pose no threat to free will. Clearly, Vihvelin’s proposed characterization of compatibilism is not ‘unproblematic’.
On a related note, one can reject the incompatibilist’s positive claim that deterministic laws pose a threat to free will without accepting that it is possible for someone to act freely when deterministic laws obtain. For instance, Neil Levy is a free-will impossibilist and, so, he accepts incompatibilism’s negative thesis that free action and the obtaining of deterministic laws are incompossible. Yet, Levy self-identifies as a ‘compatibilist’ because he rejects incompatibilism’s positive thesis that deterministic laws pose a threat to free will (Reference Levy2011, 1–2). Levy’s ‘compatibilism’ is an interesting view because it helps us to see that we can isolate the debate over whether the uniquely incompatibilist explanation for the lack of free agents in deterministic universes is correct. Yet, Levy’s compatibilist view is not clearly represented as a logically independent view in Vihvelin’s taxonomy – nor is it part of the standard taxonomy that we have inherited from Lehrer and van Inwagen. It seems that a superior taxonomy would use ‘compatibilism’ to name the negation of incompatibilism’s positive thesis (making compatibilism and incompatibilism contrary views), and ‘compossibilism’ to name the contradictory of incompatibilism’s negative thesis: incompossibilism. The resulting taxonomy would include nicely paired and intuitively named views, and would do better than either 3-FC or the standard taxonomy when it comes to representing the major views in the contemporary free-will debate.
Ultimately, the matter of which names are assigned to which views is not philosophically significant. The main point of this section is simply that at least two basic free-will views are missing from 3-FC, roughly: (1) the negative view that deterministic laws pose no threat whatsoever to free will, and (2) the negative view that deterministic laws and free will are incompossible. As such, 3-FC provides an inadequate – and somewhat confusing – map of the logical relationships between the major views in the free-will debate.
5. Conclusion
In this essay, I have argued that Vihvelin’s taxonomy, 3-FC, is problematic for a variety of reasons. First, Vihvelin inadequately defends her controversial claim that impossibilists, qua being impossibilists, cannot pinpoint deterministic laws as a (possible) threat to free will. As a result, Vihvelin fails to motivate her preferred formal definition of ‘incompatibilism, ’ according to which possibilism is a defining tenet of incompatibilism. Second, the formal definition of ‘incompatibilism’ in 3-FC fails to capture the view that Vihvelin herself associates with that term in the context of arguing that the standard formal definition of ‘incompatibilism’ must be rejected. As such, Vihvelin’s own arguments imply that the definition of ‘incompatibilism’ in 3-FC is flawed. Third, Vihvelin ignores at least two free-will views that seem to be just as basic and significant as those she gives pride of place in her taxonomy.
If my critique of 3-FC is on target, it has substantive implications for other elements of Vihvelin’s work. For example, Vihvelin uses 3-FC to motivate her contentious view that incompatibilists carry a heavier argumentative burden than compatibilists because incompatibilists (qua being incompatibilists) must endorse possibilism. In brief, Vihvelin argues the compatibilist and the incompatibilist each carry the argumentative burden of showing that there is some possible world at which he free-will thesis is true, but incompatibilists carry the extra burden of showing that the free-will thesis is true only at possible worlds where indeterminism is true. However, I have argued that Vihvelin fails to defend her claim that incompatibilists must be possibilists, from which it follows that Vihvelin also fails to defend her idiosyncratic view of the debate between compatibilists and incompatibilists. As such, there is room to doubt that Vihvelin meets all of her dialectical burdens in the defense of compatibilism that she offers in Causes, Laws, and Free Will (Reference Vihvelin, Hawthorne, Sider and Zimmerman2013).
In closing, I would like to emphasize that my criticisms have focused on Vihvelin’s proposed taxonomy and her arguments for it; I have not been critical of her efforts to make taxonomical issues an explicit topic of discussion. Vihvelin’s arguments for 3-FC, despite their flaws, make it clear that the standard taxonomy has major shortcomings as well. Given that an explicit taxonomy is also a proposed map of the logical territory in which the free-will debate takes place, I believe that future debate over competing taxonomies will shed new and much-needed light on this very old debate.
Acknowledgements
I presented several of the distinctions and arguments in this essay during my month (June 2014) as Featured Author on Thomas Nadelhoffer’s Flickers of Freedom blog. I would like to thank Thomas for the invitation and all those who commented for their help. For feedback that led to improvements in this paper, I am especially grateful to: Joe Campbell, David Chalmers, Damir Cicic, John Martin Fischer, Chris Franklin, Charles Hermes, Eddy Nahmias, Derk Pereboom, Kip Werking, and V. Alan White. I would also like to thank Graeme Forbes, Bob Hanna, Mike Huemer, Michael McKenna, Rob Rupert, Kadri Vihvelin, and an anonymous reviewer for valuable comments on earlier drafts of this paper.
