Flickers of Freedom

You Are Not an Event (Are You?)

Many accounts of the causation of overt intentional bodily actions assume that what happens when you are making your body move during an action must be explained in terms of causal relations among discrete *events*.  For example, many claim that the occurrence of a mental event non-deviantly causes the occurrence of the corresponding movements of the body.  Call this the “Event-Causal Assumption” (ECA). 

Given ECA, if you want your account of the causation of action to include a causal role for the agent in the production of her own bodily movements and actions, the typical occupant for that role is some mental event, such as a desire, belief, or intention.    

But this widespread assumption generates an equally familiar problem: if your causal role in generating your own bodily movements during an action is occupied by some mental event, there is nothing left for *you to do* with respect to those movements.  There is nothing left for you to do because all of the necessary causal work is accomplished via the relevant mental event.  This is one version of the “Problem of the Missing Agent”.

Here’s a three-step argument that purports to generate this conclusion:

(1) When you are performing an overt intentional bodily action, the movements of your body are non-deviantly caused by the occurrence of your mental events (ECA)

(2) There is no sense in which *you* are identical to any of your mental events, or to the entire set or collection of your mental events

 Thus,

(3) When you are performing an intentional bodily action, *you* are not playing any causal role in generating your own bodily movements during your performance of that action

If this argument is persuasive, for those many philosophers who tacitly or explicitly endorse some version of (ECA), how do you ensure that your account of the causation of action includes a causal role for the agent? 

I see two options: (a) you could embrace the implausible claim that you are identical to some mental event, or to the entire set or collection of your mental events; or (b) you could reject the commitment to (ECA) and find an alternative account of the causal role of the agent. 

So, should the defender of (ECA) bite the bullet and claim that you are an event?  Or should the metaphysical implausibility of that claim force the rejection of (ECA)?  Or is there some third option?

How to Escape Kim’s Logical Headlock

If the logic of the EA (given in the previous post) is valid, then only if either (i) or (ii) is incorrect, is there potentially room to develop a theory of MC. So any theory of MC that attempts to meet “Kim’s challenge” must explicitly state which premise, (i) and/or (ii), is incorrect.

To begin with, note that without the sufficiency of c, Kim cannot apply the “exclusion of over-determination” principle, so cannot rule out mental causation on the basis of the EA. The sufficiency of c is crucial if the EA is to succeed at excluding MC.

 In my book and on this blog last in Oct. 2013 I argued that the EA does not hold under indeterminism. I will repeat the argument again here because I think it is a necessary part of the foundation for everything I later want to say about how MC (including volitional MEs associated with FW) and downward causation work in the brain. If I am wrong about there being an escape from Kim’s logical headlock, the foundation of the house of MC I want to build collapses. That is, if the EA also holds under indeterminism, then MC, FW and MR are ruled out, period, and I would have to become a hard incompatibilist, whether determinism or indeterminism is the case. Is there an escape from such a bleak worldview?

Here goes. Premise (ii) does not hold if indeterminism is the case, because any particular present microphysical state is not necessitated by its antecedent microphysical state or states. In other words the traditional definition of causal closure that “every physical event has an immediately antecedent sufficient physical cause” is not satisfied, because when a cause c can be indeterministically followed by any number of possible effects e_i, then c is not a sufficient cause of any of the possible e_i, because they might not happen if they have not yet happened, and they might not have happened even after they have happened. 

Classical deterministic laws are laws that apply among sufficiently causal actualia, where both c at t1 and e at t2 are actual events. Quantum mechanical laws are instead deterministic at the level of possibilia, but indeterministic at the level of actualia, because which possible outcome will occur upon measurement is only probabilistically specifiable. Nonetheless, under quantum mechanics c is sufficiently causal of its entire set of possible outcomes e_i with their associated probabilities of occurring. It is just that c is not a sufficient cause of any particular one of its many possible effects that happens to happen when measured. Classical deterministic and modern quantum mechanical laws both operate deterministically, and causation is sufficient, but over different types of physical entities. Actualia and possibilia, while both physical, have mutually exclusive properties. Actualia are real and exist now or in some past moment; they have a probability of 1 of happening or having happened. Possibilia are not yet real and may never become real, and exist in the future relative to some c, and have a probability of happening between zero and one. A given event cannot be both actual and possible at the same time.

Closure, therefore, applies to different types of physical events under ontological determinism and indeterminism. “Closure” entails that the set of physical events is closed; Any particular effect will be a member of the same set to which a sufficient cause itself belongs. Determinism is closed at the level of actualia; Any particular cause or effect will be a member of the set of all actual events in the universe across all time. Indeterminism, in contrast, is not closed at the level of actualia because a non-sufficient actual cause and one of its possible outcomes that may never happen are not both members of the set of actualia. Rather, quantum theory is closed (and deterministic) at the level of possibilia: Any particular outcome or event will be a member of the set of all possible outcomes or events in the universe across all time, and any possible cause is sufficient to account for the set of all of its possible effects. Under indeterminism physical explanations are of a different type than under determinism, though both actualia and possibilia are physical, and theories of either are physical explanations.

An indeterministic causal closure thesis could be restated as follows: “(ii*) the set of all possible microphysical states is completely diachronically necessitated by antecedent possible microphysical states.” The realization thesis for the indeterministic case might be: “(i*) all mental states are synchronically determined by underlying sets of possible microphysical states.” But claim (i*) is contrary to the definition of supervenience. Mental events do not supervene on sets of possible physical states, they supervene on specific, actually occurring physical states. Since it is absurd to maintain that mental events synchronically supervene on sets of possibilia, we can rule (i*) out. It remains to be shown whether (i), i.e. supervenience on actualia, can be combined with (ii*), i.e. causal sufficiency and closure among possibilia, to yield (iii).

An actual microphysical state and the set of all possible microphysical states are different kinds with mutually exclusive properties (e.g., real/~real; present/~present). The essentially syllogistic structure of the exclusion argument requires staying within a logical kind. It is logically valid to draw from the major premise (ii) ‘All physical events are caused by preceding sufficient physical causes’ and the minor premise (i) ‘mental events are realized in physical events’ the conclusion (iii) that ‘the physical events that realize mental events have preceding sufficient physical causes’. But now we are splitting ‘physical’ into two types with mutually exclusive properties, possibilia and actualia. The conclusion (iii) of the syllogism holds only if both the major and minor premises hold and are both are about actualia as in (ii) and (i), or both are about possibilia as in (ii*) and (i*). If one premise is about possibilia and the other about actualia, the conclusion does not follow, because the premises are about exclusive entities. For example, (ii) and (i*) would read ‘All actual physical events are caused by preceding sufficient actual physical causes’ and ‘mental events are realized in sets of possible physical events,’ which violates syllogistic logic as much as ‘all men are mortal’ and ‘Socrates is a robot’. Conversely, (ii*) and (i) would read ‘The set of possible physical events are caused by preceding sufficient possible physical causes’ and ‘mental events are realized in actual physical events,’ which similarly violates syllogistic logical form.

In conclusion, if determinism is the case, then the EA holds, and MC, FW and MR are ruled out, as is compatibilism. However, if indeterminism is the case, the EA does not hold and MC and FW and MR are not logically ruled out, at least by the EA.

This still leaves open the hard work of explaining how MC might work in a brain that harnesses indeterministic events to make information downwardly causal, which I will take up in my next post on downward causation.

The Exclusion Argument Excludes Compatibilism Too

First, let me apologize for not answering people’s comments promptly. Now that my grant applications are done, I should be quicker to respond, and promise to respond to the many comments I have not responded to yet.

There is a deeper, logically prior problem than the FW and MR problems, namely, the mind-body problem. Granted, there are really several mind-body problems (among them the neural basis of consciousness, the neural code, the problem of how the mental is physically realized, and physically yet downwardly causal). But regarding FW and MR, the most fundamental issue is whether mental events (MEs) can be causal. If not, then the conscious deliberations we so treasure as the basis of both FW and MR are at best epiphenomenal. In reading the FW debates from recent decades, it seems that the majority of argumentation among philosophers who believe in FW involves compatibilists responding to the consequence argument (CA), and incompatibilists responding to Frankfurt cases. I think this is optimistic in the same way that arguing over how the furniture should be arranged while the house is on fire is optimistic. First we have to put the fire out, because unless we do that, there is simply no point in arguing any further.

What is the logical fire threatening to burn down the house of (free) mental causation (MC)? It is Jaegwon Kim’s exclusion argument (EA). If the EA is true, then there can be no MC. But if MEs cannot be causal, volitional MEs such as willings cannot be causal. If a fundamental component of any definition of FW is that a willing causes events to happen, but willings cannot be causal because MEs cannot be causal, then FW is not possible. Ruling out MC would rule out FW. Similarly, if a fundamental component of any definition of MR is that an act of willing causes consequences to happen for which we are in part blameworthy or praiseworthy, but willings cannot be causal because MEs cannot be causal, then MR is not possible either. No MC, no FW and no MR.

One way to try to skirt this would be to let go of mental causation, and simply try to ground FW and MR solely in the neural basis of mental events. Someone making this move would redefine FW away from mental FW and the conscious deliberations that nearly everyone really hopes to find causal. Mele, for example, hedges his bets when he frames causation disjunctively by saying that a ME such as an intention OR its physical basis causes a decision. If the EA holds, however, a ME cannot be causal, leaving only open the possibility that its physical basis is causal as a physical-on-physical event. That might be a way to save FW from the EA, but would come at the cost of accepting that mental willings cause nothing. But are physical neural events really willings? Neurons have mass. Would willings then have mass? Regardless, this move fails because the EA makes neural causation epiphenomenal as well, assuming determinism, since it also reduces to particle-on-particle causation. If we lose both MC and neural causation to the EA under determinism, we lose FW and MR utterly.

Another way to look at this is that the EA is a more devastating argument against compatibilism than the CA. The CA is problematic, I think, for at least two basic reasons. First it makes no explicit mention of causation, and second it is a modal argument. Being modal it leaves open ambiguities in the definitions of (and referents of) basic terms used in the CA (e.g., are we talking about laws-in-themselves, laws-as-modeled by science, or just conceivable laws?; are the laws in the past laws of causation or something else?; Is causation necessitarian in that it completely specifies what will happen in the future given what is?; Does causation only run forward in time?; are we talking about objectively being able to realize certain possibilities, or only conceivably being able to realize certain possibilities, whether in the past or the future?). This kind of ambiguity in what we are talking about when we talk about the past, the laws or a modal operator like van Inwagen’s ‘N’ leaves a lot of wiggle room for both confusion and talking past one another in the seemingly endless or at least stalemated back and forth over the CA. The EA, in contrast, is explicitly (not implicitly like the CA) about causation, and the EA does not provide any modal or conditional escape routes for compatibilists to take, because the EA is not a modal argument at all.

The EA rests on a premise of the causal closure of the physical. “Causal closure” means that causality at the level of particles is sufficient to account for all outcomes and interactions at the level of particles. Kim (2005, p. 17), applying Occam’s razor, advocates the “exclusion of over-determination” when modeling physical causation. In his words: “If event e has a sufficient cause c at t, no event at t distinct from c can be a cause of e.”  If particle-level causality is sufficient to account for particle behavior, and neurons are made of particles, MEs, assuming that they supervene on neuronal and particle events, can play no causal role in neuronal or particle behavior. In other words, MEs cannot cause fundamental particles to behave differently than they otherwise would have if they had only interacted according to the laws obeyed by particles. And the same goes for neural events.

Put succinctly (Kim, 1993, pp. 206–210): If (i) the “realization thesis” is the case, then each ME is synchronically determined by underlying microphysical states, and if (ii) “the causal or dynamical closure of the physical thesis” is the case, then all microphysical states are completely diachronically necessitated by antecedent microphysical states, then it follows that (iii) there is no causal work left for MEs as such to do.

I believe the EA holds if determinism is the case, ruling out MC and thereby mental FW and mental MR, though I would be delighted if someone could convince me that that is not true. Condition (i) must be true, assuming monism/physicalism, because mental events must be realized in their neural, and ultimately particle-level basis. But if determinism is true, then (ii) is also true because then events are sufficient causes of their subsequent outcomes, at least under a causally necessitarian understanding of determinism, such as held by, say, Newton or Einstein. If determinism is true (iii) follows. Thus if determinism is true, the EA rules out MC, which in turn rules out the kind of mental FW and MR most people want. Therefore FW and MR are not compatible with determinism. Note that this basis for adopting incompatibilism (of FW and MR with determinism) does not depend, like the CA, on any modal arguments with multiply interpretable operators, definitions of basic terms, or referents. The EA is so deadly for compatibilism in its simplicity because it follows from widely held assumptions of reductionistic physicalism about mental realization and physical causation.

My next post (above) will repeat some things I have written about concerning how to escape the EA, before moving on to how MC (and FW as the class of volitional MEs) might actually work in the brain.