Experimental Philosophy, Freedom, and Moral Responsibility
Philosophical discussions about the nature of freedom and moral responsibility often begin with the assumption that people are natural incompatibilists, believing that neither free will nor moral responsibility is compatible with causal determinism.1 This purported fact about people is sometimes used as evidence for philosophical theories that contend that free will and moral responsibility actually are incompatible with causal determinism and sometimes used to suggest that philosophical theories that claim otherwise inherit a significant argumentative burden to show that compatibilism is true despite our intuitions to the contrary.
In an influential study of philosophical intuitions about free will and moral responsibility, Eddy Nahmias, Stephen Morris, Thomas Nadelhoffer, and Jason Turner (2004, 2005, 2006) challenged the assumption that people are natural incompatibilists.
Consider the following vignette:Supercomputer:
Imagine that in the next century we discover all the laws of nature, and we build a supercomputer which can deduce from these laws of nature and from the current state of everything in the world exactly what will be happening in the world at any future time. It can look at everything about the way the world is and predict everything about how it will be with 100% accuracy. Suppose that such a supercomputer existed, and it looks at the state of the universe at a certain time on March 25, 2150 A.D., twenty years before Jeremy Hall is born. The computer then deduces from this information and the laws of nature that Jeremy will definitely rob Fidelity Bank at 6:00 PM on January 26, 2195. As always, the supercomputer’s prediction is correct; Jeremy robs Fidelity Bank at 6:00 PM on January 26, 2195.
If people are natural incompatibilists, then we should expect to find that most people asked to consider the Supercomputer case would judge that Jeremy did not act of his own free will when he robbed the bank and is not morally responsible for his actions.
Somewhat surprisingly, then, Nahmias et al. found just the opposite. They found that most people who are asked to consider the Supercomputer case judge that Jeremy acted of his own free will when he robbed the bank and is morally responsible for his actions.2 This suggests that people might actually be natural Compatibilists, believing that free will and moral responsibility are in fact compatible with causal determinism. If people are natural compatibilists, then this suggests that it is compatibilism that should be afforded a significant default positive epistemic status and that incompatibilism inherits the argumentative burden of having to show that it is true despite our intuitions to the contrary.While this would suggest a reversal of fortune in the philosophical discussion about free will and moral responsibility, Shaun Nichols and Joshua Knobe (2007) suggest that we can reconcile these results with the view that people are natural incompatibilists by paying close attention to the role that affect is playing in generating the relevant philosophical intuitions. According to Nichols and Knobe, while people are natural incompatibilists, they can come to form compatibilist intuitive judgments when presented with affectively charged vignettes. The underlying idea is that people’s emotional responses to the affectively charged vignettes serve to distort their judgments about whether moral responsibility is compatible with causal determinism, drawing them away from their natural incompatibilism to an unnatural compatibilism. If this were right, then it would seem that we could explain the fact that most people asked to consider the Supercomputer case judge that Jeremy acted of his own free will and is morally responsible for his actions without having to abandon the view that people are natural incompatibilists.
But, is this view right? Are people natural incompatibilists whose intuitive judgments are distorted by their emotional responses to affectively charged vignettes? In order to see whether this is the case, Nichols and Knobe ran a study involving both abstract questions lacking affectively charged content and concrete cases having affectively charged content.
Nichols and Knobe began by providing people with the following descriptions of determinism and indeterminism:Imagine a universe (Universe A) in which everything that happens is completely caused by whatever happened before it. This is true from the very beginning of the universe, so what happened in the beginning of the universe caused what happened next, and so on right up until the present. For example, one day John decided to have French Fries at lunch. Like everything else, this decision was completely caused by what happened before it. So, if everything in this universe was exactly the same up until John made his decision, then it had to happen that John would decide to have French Fries.
Now, imagine a universe (Universe B) in which almost everything that happens is completely caused by whatever happened before it. The one exception is human decision making. For example, one day Mary decided to have French Fries at lunch. Since a person's decision in this universe is not completely caused by what happened before it, even if everything in the universe was exactly the same up until Mary made her decision, it did not have to happen that Mary would decide to have French Fries. She could have decided to have something different.
The key difference, then, is that in Universe A every decision is completely caused by what happened before the decision - given the past, each decision has to happen in the way that it does. By contrast, in Universe B, decisions are not completely caused by the past, and each human decision does not have to happen the way that it does.3
Nichols and Knobe found that after reading the descriptions of determinism and indeterminism, most people who are asked whether it is possible in Universe A for an agent to be morally responsible for her actions judge that it is not possible.4 That is, most people when asked an abstract question about the compatibility of causal determinism and moral responsibility judge that the two are, in fact, incompatible.
But, consider the following vignette:Murderous Husband:
In Universe A, a man named Bill has become attracted to his secretary, and he decides that the only way to be with her is to kill his wife and 3 children. He knows that it is impossible to escape from his house in the event of a fire. Before he leaves on a business trip, he sets up a device in his basement that burns down the house and kills his family.
Interestingly, Nichols and Knobe found that most people who were asked to consider the Murderous Husband case judge that Bill is morally responsible for killing his wife and children even though his actions were causally determined.5 It seems, then, that people are natural incompatibilists when presented with abstract questions lacking affectively charged content, but that they come to form compatibilist intuitive judgments when presented with concrete cases possessing affectively charged content.6 Nichols and Knobe contend that what explains this fact is that people's emotional responses are distorting their judgments. While this doesn't go far enough to show that incompatibilism is true, it does suggest that maybe Nahmias et al. were too quick to conclude that people are natural compatibilists. Instead, we might say that people are unnatural compatibilists.
There is a problem, however, with attempting to explain away the observed variation as a matter of performance error.7 To describe one process as interfering with another presupposes an understanding of the processes involved. If we already have a well- worked-out account of the particular mechanisms responsible for our moral responsibility judgments or a characterization of the function that the cognitive mechanism responsible for these judgments is supposed to compute, then we might be in a position to determine whether or not our emotional responses interfere with the proper function of those mechanisms - that is, whether or not the influence of our emotional responses constitutes a performance error. The problem is that we don't have this.
What we have is extensional, distribution data: given scenario x under conditions y, a certain percentage of subjects give answer z. But this provides only an input/output account of what function the mechanism is computing.8 It doesn't provide us with an understanding of how this computational process is implemented, in particular about the relevant representations and algorithms, or how this computational process is realized physically.9 Without something like this kind of information, at least in the background, it becomes quite difficult to separate factors that contribute to competence from factors that contribute to performance error, especially when we are dealing with large, systematic variation. So, it seems that Nichols and Knobe simply aren't in a good position to conclude that people are natural incompatibilists who are drawn to some unnatural form of compatibilism by their emotional responses to affectively charged content. In the absence of the right kind of account, which they just don't seem to have, of the particular mechanisms responsible for our moral responsibility judgments, we simply cannot tell.There is another possibility that we've overlooked so far. Maybe some people are natural compatibilists, while others are natural incompatibilists. For example, maybe there are multiple concepts of moral responsibility, according to some of which freedom and moral responsibility are compatible with causal determinism, and according to others of which freedom and moral responsibility are incompatible with causal determinism. This possibility is suggested by the fact that empirical studies demonstrate that hypothetical cases give rise to a number of different intuitive responses and is underscored by recent empirical studies that suggest that personality differences can affect whether people are natural compatibilists or natural incompatibilists (see, e.g., Feltz & Cokely 2009).
This possibility also has the advantage of bypassing the problem just raised for Nichols and Knobe's unnatural compatibilism view. Since we would no longer be called upon to explain away observed variation in terms of performance errors, our inability to tell whether or not our emotional responses to affectively charged content is part of our competence at making moral responsibility judgments loses some of its sting.In order to see whether or not it is true that some people are natural compatibilists while others are natural incompatibilists, Adam Feltz, Edward Cokely, and Thomas Nadelhoffer (2009) ran a study asking people to consider vignettes containing affectively charged content and vignettes lacking affectively charged content. In particular, they had people consider the following two vignettes, borrowed from Nichols and Knobe (2007):
Serial Rapist:
[In a deterministic universe], as he has done many times in the past, Bill stalks and rapes a stranger.
Habitual Tax Cheat:
[In a deterministic universe], as he has done many times in the past, Mark arranges to cheat on his taxes.
Interestingly, Feltz et al. found that most people who were asked to consider both cases either judged that neither Bill nor Mark is morally responsible for his actions or judged that both Bill and Mark are morally responsible for their actions.10 These results are consistent with what they call the multiple concepts view - the view that some people are natural compatibilists while others are natural incompatibilists. Additionally, these results are inconsistent with the other positions that we've considered. Natural incompatibilism would have predicted that most people would judge that neither Bill nor Mark is morally responsible for his actions, natural compatibilism would have predicted that most people would judge that both Bill and Mark are morally responsible for their actions, and unnatural compatibilism would have predicted that most people would judge that Bill is morally responsible for his actions (because this case is affectively charged) but that Mark is not morally responsible for his actions (because this case is not affectively charged). Since none of these expectations was realized, it seems that we have additional reason to doubt these views.
The multiple concepts view is not without its own problems, however. In particular, it creates a troublesome dilemma.11 Philosophers are interested in moving from claims about people's shared intuitive judgments to claims about the epistemic standing of philosophical theories. But, if some people are natural compatibilists while others are natural incompatibilists, then we shouldn't expect to find shared intuitive judgments. Two options seem available. On the one hand, philosophers can opt to select one from among the different intuitive judgments that are generated in response to any given real or hypothetical case. But, philosophers taking this option inherit the problem of explaining why the other intuitive judgments should be discounted. And, as the growing literature in the epistemology of disagreement demonstrates, determining just what to do when confronted with conflicting evidence is not especially straightforward.12 On the other hand, philosophers can opt to relativize their conclusions.13 But, while such a move might be appropriate in some instances, this option is unlikely to prove generally attractive. In particular, it has been historically difficult to move from descriptive relativism, the view that certain groups of people have different ways of thinking about things, to normative relativism, the view that the right way to think about things is relative to certain groups of people. Since one option isn't particularly straightforward and the other isn't particularly attractive, the multiple concepts view poses a significant challenge to the idea that we can move straightforwardly and unproblematically from claims about people's philosophical intuitions about moral responsibility to claims about the truth or plausibility of certain philosophical theories of moral responsibility, one that has yet to be answered.14
At this point, it is natural to wonder what progress has been made.15 Experimental philosophers were initially drawn to philosophical discussions about the nature of free will and moral responsibility because these discussions typically involve appeals to philosophical intuitions. Compatibilists and incompatibilists alike trade on arguments that moved from claims about people's intuitive judgments to claims about the truth or plausibility of philosophical theories about the compatibility of freedom, moral responsibility, and causal determinism. Experimental philosophers hoped to help move these discussions forward by providing a clear picture of the relevant intuitions themselves and insight into the psychological mechanisms and influences that shape them. A clear picture of the relevant intuitions would help us determine which arguments to accept and which to reject. But reality has turned out to be more complicated than expected. Instead of coming to have a single clear picture of the relevant intuitions, we have come to have several competing pictures: maybe people are natural compatibilists, believing that free will and moral responsibility are compatible with causal determinism; maybe people are natural incompatibilists who are drawn to some unnatural form of compatibilism by their emotional responses to affectively charged content; maybe there is no single set of intuitions about the compatibility of free will, moral responsibility, and causal determinism. Since we don't yet know which picture is right, we can't determine which arguments to accept and which to reject. We simply can't move the discussion forward at this time. But it is important to see that recognizing this fact, that right now philosophical discussions about the nature of free will and moral responsibility can't progress on the basis of our intuitive judgments about real or hypothetical cases, is itself progress and is a significant contribution to the state of play in contemporary philosophical discussions of free will and moral responsibility. After all, sometimes finding out that you can't use a certain tool, at least right now, is just as important as coming to find the right tool to use.
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