CPBD 085: Marcel Brass – The Neuroscience of Free Will

by Luke Muehlhauser on January 16, 2011 in Free Will,Podcast,Science

(Listen to other episodes of Conversations from the Pale Blue Dot here.)

Today I interview Marcel Brass, one of the leading researchers in the brain science of free will and intentional action.

Download CPBD episode 085 with Marcel Brass. Total time is 51:18.

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Transcript prepared by CastingWords and paid for by Silver Bullet. If you’d like to get a transcript made for other past or future episodes, please contact me.

LUKE: Dr. Marcel Brass is a professor of experimental psychology at Ghent University in Belgium and he also works with the Center for Cognitive Neuroscience at Ghent University. He is the author of numerous publications in psychology, neuroscience and philosophy.

Marcel, welcome to the show!

MARCEL: Yeah, thanks for having me.

LUKE: Marcel, I want to ask you about recent work in the neuroscience of free will but first I’m hoping you could explain to us more generally, how much we currently know about the brain?

It seems like we know a lot about how individual neurons communicate and we know a few things about which areas of the brain are usually associated with certain functions, but we seem to know very little about the broad logical structure of the brain and how it does what it does. Is that right?

MARCEL: Yes, I absolutely agree. We have learned a lot about brain function during the last 15 years since this new brain imaging techniques such as functional MRI developed.

But we are also faced with a number of problems that we didn’t expect when we started to investigate the brain with such brain imaging techniques.

One major problem is that this localization approach – that means attaching specific brain functions to specific regions of the brain – turned out to be much more difficult than we expected, and this has a number of reasons.

First it turned out that, I mean there only are a restricted number of brain regions but we have in principle an infinite number of cognitive operations. So what happens is a lot of cognitive functions have been attached to specific brain areas.

For example, Broca’s area is a region in the frontal lateral cortex, so in the anterior part of the brain, and language people would say that this is an area that’s involved in language production while researchers doing action research would say it’s involved in imitation. And there are maybe twenty or thirty other functions that have been related to this brain area.

So now the crucial question is: what is the real function of this region?

And I think the problem occurs because traditionally from experimental psychology, we are determined by specific disciplines. So for example, when I’m a memory researcher or a language researcher I would interpret my results in terms of language. But when I’m an action researcher I interpret my results in terms of motor control for example.

At the moment we have problems to integrate these different perspectives. But this is absolutely necessary in order to get a broader view of cognitive operations that are implemented in specific brain areas. And this is one major problem at the moment.

Another problem is that the cognitive role of specific brain areas is not only determined by the specific brain area but usually the cognitive function in a specific, broader cognitive operation is determined by networks of brain regions.

So to come back to my example, Broca’s Area, together with other language areas might be involved in language production but together with other motor areas might be involved in imitation.

So we have to look at networks of brain activity rather than on single brain areas. And where we have started to do that, this is a very complicated issue in a way and we are only starting to understand the networks that are involved in specific tasks.

I think the third problem is that we don’t really have an understanding of the information flow in the brain. So the problem with the most commonly used technique in cognitive neuroscience memory function, magnetic imaging – resonance imaging – is that it doesn’t have a very good temporal resolution.

So we can’t really see online how brain activation interacts or changes across brain regions and therefore we don’t really have a good understanding of the information flow within the brain.

In some domains we have, in the visual domain I think there is a very good understanding how that works, also from monkey research.

But in more complex domains like research on cognitive control or intentional action, we don’t really have a good understanding how informations are transferred between different brain areas. And I think that’s the third major problem we are facing.

LUKE: So Marcel, you just spoke about a lot of the big-scale results that are coming out of using fMRI to look at the activity between different brain regions. It seems like we’re also making some inroads into determining the structure of the brain by looking at the very small level, at individual neurons and how they’re talking to each other.

I think, for example, some of our most developed studies there regard how we perceive visual stimuli. Is that right? Could you talk a little bit about the progress that we’re making in that front?

MARCEL: Yeah, of course. I mean, there are different levels to look at brain function. And I’m a psychologist, therefore my expertise lies primarily in the systems level, to look at the role of larger brain regions that are a few centimeters large in cognitive function.

But of course you can also look at single-cell activity. So for example, you can show a monkey an object, and then record the activity of a single neuron during this experiment.

And this also gives you information about the neural processing that takes place in specific brain areas, but then on the single-cell level. And in a way, this is a very fruitful approach, because when you look at the single-cell level, you measure directly the neural activity- the electrical activity – of the neuron.

So you have a very good idea about the temporal resolution. And also you can study specifically which kind of information encoded in this single cell.

But on the other hand, you have a broader perspective. So you have in the brain regions millions of cells that are firing in synchrony. So the problem is always to bridge the gap between this single-cell level and the systems level; the level of brain areas.

Yeah, it’s interesting. I think to some degree these informations are complementary, but sometimes they also lead to completely different conclusions.

So the problem is really to integrate these different levels. And if you ask a single-cell person, so a person who is doing single-cell recordings in monkeys, about a specific brain area, what this brain area is doing, you might end up with a completely different answer than if you ask somebody doing functional brain imaging, who looks more at the larger-scale activity of the brain.

That is certainly a challenge in the future, to integrate these different levels of investigation.

LUKE: So, Marcel, it seems that neuroscience in particular is very driven by the tools that we have available to us. And I think most people are familiar with fMRI, but what are some of the other tools that we have available, and what tools are we trying to develop?

MARCEL: First of all, in my opinion, if you are interested in cognitive function, the most important tool, so to say, is the experiment. So Experimental Psychology; the experimental method.

Because if you don’t design good experiments, you can’t come up with good answers on the question, which brain areas, for example, are involved in specific cognitive operations. But of course, we have different dependent measures.

So the most traditional measure was reaction time. You show participants, for example, specific stimuli, and then you measure how fast they react. And there is a long history of research with reaction time, more than a hundred years. So this is a very interesting tool, still.

Even though we have now these new fancy brain imaging techniques. From a brain perspective, we have these new brain imaging techniques such as Functional Magnetic Resonance Imaging and Positron Emission Tomography, which measure not really the neural activity directly, but where the blood flows.

So we have a very indirect measure of the neural activity. That is the reason why these brain measures don’t have a very good temporal resolution. But they have a relatively good spatial resolution. Then we have also intervention techniques, for example, Transcranial Magnetic Stimulation.

In Transcranial Magnetic Stimulation, you induce a very strong magnetic pulse over a specific brain region. And this disturbs the operation of this brain region for a relatively short period in time, so you can see what happens if you – in a way – knock out the specific brain area. And this is very crucial because most of the other techniques we are using are correlational techniques.

So we find activation, for example, in a specific visual area when we show a specific stimulus. When we show a face, we find activation in Fusiform face area. But the question is, is this activation really necessary to perceive a face? And this is difficult to answer from this correlational methods, such as a functional MRI.

In order to draw this conclusion, we need these intervention methods, where you knock out a specific brain region and then can show that participants can’t perceive a face anymore, for example.

Then we have older techniques to measure brain activity. One is single-cell recording, that is already relatively old. But the problem is that you can’t do it in humans, or only in exceptional cases, in epileptic patients, where you place electrode grids for diagnostic purposes.

But in principle you, of course, can’t do single-cell recordings in humans because you have to place an electrode in your brain, so you have to open the skull.

Then there are methods that allow to measure electrical activity from outside. This is EEG – electroencephalogram. And this is also relatively an old method that has a relatively long tradition. And we are still using these methods.

And then we have methods that work similar, like MEG, where you don’t look at the electrical field, but the magnetic field, so the spatial resolution of this method is much better than with EEG. Now that’s in principle… these are in principle the most common tools we use in cognitive neuroscience at the moment.

They all have their advantages and disadvantages, that is crucial to know. There is not one method that solves all the problems.

LUKE: And what’s the difference between experimental psychology, neuroscience, cognitive science, cognitive neuroscience?

MARCEL: So experimental psychology is, in principle, a discipline that is relatively old. It is about 100 years old. And it started primarily with reaction time research. So you present specific stimuli and then you record how long it takes participants to respond to the stimuli. And in this discipline, the experimental method develops to investigate cognitive operations. And we got quite far with that.

But more recently these new methods were developed, such as EEG, fMRI, and PET, with which you record electrical activity.

So in principle, you have a different dependent measure. You use the same kind of experiments, but you measure something different than reaction time. You measure neural activity. And this signal, of course, is very rich and gives us a lot of information.

So cognitive neuroscience is about investigating cognitive operation with brain activity as the dependent measure. That’s at least how I would understand it.

And neuroscience is even a broader discipline. Neuroscience, in general, is interested in the functioning of the brain on different levels. On the molecular level, on the single-cell level, on the systems level.

So it includes cognitive neuroscience, but it’s interested in the understanding of the brain, while cognitive neuroscience is primarily interested in understanding the cognitive system, using brain activity as a measure.

LUKE: Well, Marcel, thank you very much. That’s a wonderful introduction to some recent study of the brain.

I’d love to talk to you now about free will. For centuries, philosophers have argued about whether or not we have what I call contra-causal free will, which is that kind of free will that would allow us to be unmoved movers of our own actions, at least some of the time, for some actions.

But recently, it looks like science, and neuroscience in particular, might be able to answer this question for us. My understanding is that Benjamin Libet really good things going here, is that right?

MARCEL: Yeah. I absolutely agree. First of all, I do not really think that neuroscience will solve the old philosophical problem whether free will exists or not. And I’m not even sure whether any science will solve this problem.

But neuroscience can inform us about the basis of our experience of free will. So our subjective experience of will and how it is related to our behavior. And certainly the experiment of Benjamin Libet was very influencing in getting this research going.

So first of all, it might be good to briefly describe the experiment that Benjamin Libet carried out. So in this experiment, participants have to carry out simple actions. They have to press a key or release a button. And they can do that whenever they want. So not completely, but they have a specific period of time where they can decide to press a key.

While they are doing that, they are watching a clock hand rotating. And after each trial, they tell the experimenter on this clock when exactly they decided to press a key. So their subjective experience of will as Libet called it, the “W judgment,” – the will judgment.

Now you can first relate this W judgment to the response. So you know when participants actually press a key. And then you can look at this subjective experience of will and it turned out that about two hundred milliseconds before participants press a key, they say that they experience the intention to press a key.

Now the ingenious idea of Libet was to relate this subjective experience of will to neural activity. So he used EEG; electrical activity to in a way see where the brain already starts to process information before we decide to act in a way.

Benjamin Libet measured EEG potential in a mortor potential that is called Bereitschaftspotential, or readiness potential, and this Bereitschaftspotential precedes voluntary action. So if you press a key and you average back the activity in the EEG you find this Bereitschaftspotential.

Now the crucial question was whether the Bereitschaftspotential started to rise before participants said that they intended to press a key or afterwards. And a somewhat surprising finding was the Bereitschaftspotential starts about a second before participants indicate that they are going to press a key. So this seems to indicate that our decision to act is preceded by brain activity for more than a second or so.

Benjamin Libet concluded from this that in principle, our intentional decision to act doesn’t get this thing going in a way, but rather is a consequence of unconscious brain… unconscious processes that are reflected in this brain activity.

So our subjective experience of will is not what is initiating the whole thing, but is a consequence of something that is already going on in the brain.

By relating the subjective experience of willing something to brain activity, he tried to draw conclusions about the question: how free we can come up with our decision or to what degree we are determined by brain activity in our decisions.

LUKE: Now, some people criticize that conclusion that Libet made. How did those criticisms go?

MARCEL: So, first of all, there is a lot of methodological criticism about the study.

One problem of the Libet experiment is that it relies on recall. So participants do not directly tell you when they have an intention. But they tell it afterwards. So they have to recall the position of the clock, in a way.

The second problem is that this Libet clock, or it in principle a Vunt clock, it wasn’t already introduced in the beginning of the 20th century. But this Libet clock introduced some biases. So it is very difficult to determine the exact position of the moving stimulus.

And we know that from other research on perception of moving objects, for example. So there is another bias related to that.

And finally, introducing this report of intention, might change the intention itself in a way. So because you have to report on your intention, the way you formed your intention might be change. So that’s another methodological critique.

But then they are more general criticisms of the method. So one crucial question is: Whether the readiness potential – this brainwave – is always followed by an action. And this is difficult to figure out because you back average this brainwave from the action. So it’s difficult to observe when you don’t have an action.

But in principle, it could well be that you sometimes, show a gratuitous potential but then you don’t act. But if this would be the case, then it could be possible that they always readiness potentials, but we can nevertheless decide on whether this leads to an action or not.

LUKE: Right.

MARCEL: So that would also completely change the conclusions you can draw from this experiment.

Finally, there is of course a very general or more philosophical question that is crucial namely: the Libet experiment is based on the idea that willful influences on our behavior are in a way conscious; so the whole experiment is about it becoming aware of the intention to act.

But if you assume that the will can also operate on unconscious processes or that you can have pre-conscious intentions also, that would also of course change the whole idea because then discovery judgment wouldn’t tell us how do you think about our volition or our will.

LUKE: Very interesting. Now there’s a more recent study that maybe an improvement on Libet’s work by Masao Matsuhashi and Mark Hallett.

Could you explain that study, and what it’s implication might be for our understanding of intentional action?

MARCEL: I think it’s a very interesting and clever study that they did. So as I said, one criticism of the Libet’s experiment is that you have to read this clock, and afterwards report on the position of the clock when you form your intention.

So they try to overcome this methodological critique by using a completely different method to determine the intention to act. So the way that they did this was, the participants had to carry all the Libet kind of experiment. So they had to press the key, whenever they wanted to press the key.

But during their experiment, they played back tones at specific points. And when participants heard the tone, and were forming the intentions at that point, they should stop the action. But if they heard the tone at any other point in time, so when they haven’t formed any intention to act, they should simply contend.

Now, this also looks at the distribution of the tones to which participants reacted. And from this distribution, you can in principle infer indirectly the time when participants form the intention to act because when they form the intention to act they would not respond. So this trial wouldn’t be in the distribution.

So you can indirectly infer from this shape of the distribution when participants form the intentions to act, because in this situation they wouldn’t act, and this wouldn’t occur in this distribution.

So with this indirect method, that has the advantage that it is not based on recall because participants immediately report indirectly by not acting that they had the intention to act. They showed that the intention to act already started more than a second before participants actually responded. So this is a few hundred milliseconds earlier that reported by the Libet method.

Interestingly, nevertheless this intention to act started after the onset of the readiness potential. So in this sense, results of this study are very similar to the Libet study experiment.

Even though one has to say that in some subject, the intention started before the readiness potential but in most of the subjects it started after the readiness potential.

So what this study in a way shows is that the intention to act seems to start much earlier than has been demonstrated by Libet. That is a little bit the problem of the whole method to use subjective experience to determine when participants intend to act because it depends firmly on the method.

So you could imagine the comparison between this experiment and the Libet experiment in the following way.

Let’s assume you were sitting in a conference and somebody asked you whether you want a coffee or not. The likelihood that you say, “Yes I want a coffee,” is presumably much higher than if you would have decided yourself to drink coffee. So there might be an intention to drink coffee, but you wouldn’t have taken a coffee at that point yet.

But if somebody ask you, you say, “Oh yes, I want a coffee.” So it depends a little bit on the degree or the strength of the intention when you can detect it in a way and the method how you detect it.

LUKE: Now some other studies have tried to get at this issue using that tool that you described, Transcranial Magnetic Stimulation. How does that work?

MARCEL: I think you are referring to… I hope you are referring to a study by Hi Kwong Lau and what he was doing is again a very clever experiment.

So we know that our experience of intending to act is related to a specific brain area and he himself has done a study where he showed that. But it’s also known from other experimental studies on intentional action that a specific part of the brain pre-SMA or more precisely pre-SMA-SMA complex seem to be involved in this intention to act.

He was interested in the question, what happens if you disturb the functioning of this brain region? So the question was whether this would change the experience of will. And it does. So it changes the onset of the experience of will, so the W judgment.

That is in itself not extremely surprising. Of course if there is a brain region that is involved in the formation of the intention and you knock out this brain region of course, it changes the way you experience your intention.

What was surprising though, was that it also changes the time of your intention when you stimulate after participants executed the action. So he stimulated after participants pressed a key and nevertheless you found a shift of the W judgment. And this seemed to suggest that brain processes happening after you already executed the action change the way you report your intention to act.

This, of course, is not very comfortable with the view that in principle the reported time of intention is a very trustworthy indicator of your intention because I mean how can the intention be influenced by something that happens after you act?

There is now some evidence, also behavioral evidence, that this is a case that in a way your experience of will is a reconstruction to some degree at least, of information that happened after you already acted. So it’s not only influenced by what you are thinking at that point but also what happens afterwards.

And there is a nice behavioral study that has shown this point as well. They used also Libet’s kind of experiment but after participants press the key they played back a tone. So the key press had an auditory consequence. You decide to press a key and then you hear a tone.

Now they will vary the interval of the tone after the key press and what they found was that depending on the interval of the tone the W judgment changed.

So your reported intention of will changes depending on what happens after the action. And again, this seemed to indicate that this reported intention to act is not always a good indicator of your intention, but it seemed to be also influenced by information integration after you already acted – so by a kind of reconstruction of your intention.

LUKE: Now, in their Transcranial Magnetic Stimulation study, in what way did that interruption of that brain region, how did that actually change the experience of intending?

MARCEL: That’s a very interesting question and I think it’s very difficult to answer what exactly is happening, why it shifted the W judgment.

I think what we can say at the moment, and we also did an EEG study with a second experiment, I told you, this experiment by Banks & Isham. And what we think is that our experience of intending to act is presumably related to the intention, but it is also related to the processing of information after you have acted.

So it’s a kind of integration of information over a longer period of time. And this integration of information might be changed when you knock out briefly this brain area that has been related to the formation of the intention.

How exactly that works is, of course, a very difficult question. The crucial point in the Lau’s experiment is that stimulation after the action changes your experience, or at least the recorded time.

LUKE: Right. Now, Marcel, you’ve done some research on this issue as well. One of your studies was conducted with Simone Kuehn? Did I pronounce that correctly?

MARCEL: Yes. Simone Kuehn.

LUKE: How did that study work?

MARCEL: The logic of the study is a little bit similar to the studies I told you about. These studies that show that information that happened after you responded seemed to influence your experience of intention.

In this experiment we asked participants to respond to a letter by pressing a key. And they should do that as fast as possible. So participants are really in a mode where they press as fast as possible when they see a specific letter.

Now, in some trials, the letter changed color. And in this case, participants had to decide whether they want to press the key or whether they stop pressing the key and don’t press the key.

So they have a decision, they are decision trials, where they can decide between pressing and not pressing. The point is, it depends a little bit on when you introduce this change of the color of the cue. If you do that too early, participants can’t stop their response. So they will simply press the key. Because the information that they should think about comes too late, so they can’t really respond to that.

If you present this signal later, then participants first have to stop pressing the key, and then they have to decide whether they want to press the key or not. And this takes time. It takes a few hundred milliseconds to come up with this decision whether you want to press a key or not.

Now in some cases, from an outside perspective, it looks very similar. So when you, for example, press the key and then the signal appears, but you can’t stop the key press because the signal appeared too early, so you can’t really stop your key press anymore.

And then you have the situation where you want to press the key, then the signal occurs, and then you decide, no, I don’t press immediately, I first decide on it, then you decide and press the key. So in principle, in both cases, participants press the key, but in one case, they have an additional decision to do it, and in the other case they simply respond to the stimulus.

And because you can’t distinguish these two trials easily, trial tests easily, we asked participants after each trials whether they decided or simply weren’t able to stop. So what you would expect is that in cases where participants report that they decided to press the key, their response times should be much slower.

Because in these cases they first have to stop the action, and then implement the decision and then press the key. So they should be a few hundred milliseconds slower than in trials where they simply press the key, or where they get the signal but can’t stop themselves from pressing the key.

And in most of the trials, this is really the case. So in two-thirds of the trials, participants are about 500 milliseconds slower if they decide to press the key, compared to the situation where they simply press the key.

However, and this was really surprising, in one-third of the trials, participants tell us afterward that they decided to press the key, but they are nevertheless as fast as if they didn’t come up with a decision, but simply responded. So from these reaction times, from these extremely fast reaction times, one can really doubt the report of the subjects.

Because if they really have decided on it, they should have been much slower. In this sense, you could either assume that they were lying, and we try to exclude this possibility by correlating the data with live questionnaires and stuff like that, or sometimes they don’t have a very good insight into their own intentions.

Because they think afterward, “Oh, yes, I intended to press the key, ” while in fact, they didn’t really decide on it. They simply pressed the key. So this data also suggests that sometimes our experience of intending to act seems to be a reconstruction of things that happen afterward. So you interpret your behavior in this specific way retrospectively, even though there was no intention in the first place.

LUKE: What are some of the broader conclusions that you might consider drawing from that study that you did?

MARCEL: I mean, it is very difficult to draw extreme conclusions. Because, I mean, as we showed, in most of the trials, participants judged their intentions correctly. Only in some trials did they misjudge their intentions.

What I think about these results and other results is that our experience of intention to act is influenced by a number of factors. It is influenced by maybe our deliberation about the decision. It is influenced by information that happened after we responded.

So it is, to some degree and in some situations, a reconstructive process. And a third influence on our actions might be unconscious informations that are in the system and bias our decision.

So in principle I would conclude from this experiment and other experiments that our experience of will is a mixture of a number of factors.

LUKE: Marcel, what are some of the other experiments that you’ve worked on to get at the nature of intentional action and free will?

MARCEL: One experiment that I think is interesting in this context, and also relates to what I said before, is an experiment I did in collaboration with John-Dylan Haynes.

So there we tried a kind of fMRI version of the Libet trials. And the goal of this experiment was to predict decisions of participants from brain activity, and to see how far in advance we can predict the decision of the subject. So in this experiment, participants had to decide between two response alternatives. They could press a left or right key.

They could determine themselves when they pressed the key and which key they pressed, and we measured brain activity with fMRI while the participants were coming up with this decision. And then we used a specific way to analyze brain activity to predict their decisions from brain activity. So what we were looking at, we looked at specific pattern of activity that predicted what participants will later do.

And the interesting finding in this experiment was that already, six or eight seconds before you report that you will press the key, we could predict the decision to some degree, with a 60 percent accuracy.

I mean, this is far from being deterministic, that’s a very crucial point, because I mean chance is 50 percent, so we are a little bit above chance; 10 percent.

But on the other hand, this experiment shows that already eight or ten seconds before you come up with a decision, there are informations in the system that bias your decision. And obviously you have no idea about these biases.

This is an interesting study because, yeah, it shows our experience of will is to some degree a reconstruction of what happened. But it is also determined by information that are in the system, and is also pre-determined to some degree by this information.

LUKE: Well, yeah, six to eight seconds is a very long time.

Are there other experiments that you could conduct, that perhaps you would be able to predict people’s choice with a greater degree of accuracy, but say, maybe, two or three seconds before the action? Do you think that’s plausible?

MARCEL: Yeah, of course. I mean, the closer you get to the action, the easier it is to predict the decision. And so if you look at the point in time where they really act, and you look at motor cortex – the area where the motor command is generated — you can predict with an 80 or 90 percent probability.

The problem with fMRI is that the temporal resolution isn’t very good. So if you get too close to the response, you don’t really know any more whether you are really predicting or postdicting.

In this sense, it was very crucial to show that already very early on you can predict the decisions from brain activity, because it’s eight seconds in advance. You can’t argue that, because of the inaccuracy of the measure you can’t draw the conclusion.

I would assume that the closer you get to the decision, the better you would be able to predict. But this, in my opinion, hasn’t been systematically investigated. But it’s a very interesting question.

LUKE: Do you have other experiments that you know of that you think are really interesting results in trying to investigate the nature of free will through the tools of cognitive neuroscience?

MARCEL: Recently I have started a series of experiments which is motivated by very nice social, psychological finding. It provides a completely different perspective on this question of free will.

Then you’d be a social psychologist. It doesn’t really matter whether we believe in free will or not. So in other words, what happens if it turns out that free will is an illusion? That it doesn’t exist? Would it change our behavior?

They developed a very clever way to investigate that. They gave participants brief text vignettes, with statements. And one group of participants got a statement where these texts claimed that free will is an illusion; that it doesn’t exist; that scientists has demonstrated that free will doesn’t exist.

So participants had to read these text messages and then afterwards they had to do something else. But I will come to that. And they had another group where participants had to read messages that supported the idea that free will exists.

Reading these text messages seemed to influence your belief in free will. So that you can use a questionnaire to measure that and participants who have read the text vignette that claimed that free will does not exist showed lower scores on this free will questionnaire.

So, reading these messages seemed to influence your belief in free will, at least on a very short term basis.

Now, the interesting idea of these social psychologists – it was first Foss and Scoler – was that they then brought participants in a situation where they could cheat. And what they found was that participants who read the text passages, the text vignette that stated that free will does not exist, cheated more than the other group.

Other experiments have shown that questioning belief in free will or providing a deterministic world view leads to anti-social behavior. And I found that very interesting, because this is something… we have to debate about free will. But this addresses really whether this debate might have any consequences.

Now, I’m a cognitive psychologist. I’m not a social psychologist. So when I first heard about these experiments, I thought, “OK, they can show that these beliefs about free will influence very complex social behavior.” But for me the question was, “Why would they also influence basic motor cognition?”

What we did in a recent study – it’s not published yet… but it will hopefully soon. We did a similar kind of manipulation. So, one group of participants had to read texts that stated that free will is an illusion and doesn’t exist, and science has shown that it doesn’t exist.

Another group of subjects read a text that was not about free will at all. It had a similar complexity. It was about consciousness.

Then we asked participants to carry out the Libet task. They didn’t know that there was any relationship between reading the text in the beginning and then carrying out a Libet task. So we left participants to carry out the Libet task and measured EEG as well.

I was expecting that maybe the W judgment might be changed in the group that their belief in free will was questioned. But what we actually found was that the readiness potential changes. So, participants who read the text that free will is an illusion showed lower readiness potential.

The change in the readiness potential occurs about one and a half seconds before participants press a key, and more than a second before they reported that they found intention. So, these data seem to suggest that such high-level belief about free will and determinism affect brain correlates of pre-conscious motor preparation.

I think this is a very interesting finding in a way. Because it shows that this debate on whether you believe in free will seem to affect your basic motor processes.

LUKE: So, I’m not quite understanding, how does, for example, reading the passage about how science has disproved free will and all that kind of thing… How does that affect the readiness potential, and what does that mean?

MARCEL: That’s a very interesting question. I mean and we can at the moment only speculate about the precise mechanisms — how these high-level beliefs about free will influence our basic motor cognition.

I mean, the way we think about it is, that in a way, if you believe that free will doesn’t exist, this has an influence on your self-efficacy. So the control you experience over your actions.

We assume that these beliefs influence your experience of self-efficacy. And this, in turn, influences how you are involved in a specific task. So if you think that it doesn’t matter anyway what I’m doing, you might put less effort into such a task.

And this then leads to a modulation of the readiness potential.

LUKE: OK. Got you.

MARCEL: But this is at the moment very speculative. Because I mean, that this is simply the first study that shows we can find these influences of relatively high-level beliefs on basic motor cognition. And what I’m now interested in is really investigating the functional and neural mechanisms that modulate this influence.

LUKE: Those studies about the effects of belief in free will on people’s behavior are really interesting to me as well.

I’ve read that some researchers or some philosophers think that this indicates maybe we should not… Let’s say science discovers a lot of things that really place heavy, serious doubt on the existence of free will, and some people like Saul Smilansky will argue that the scientists and philosophers who are investigating free will shouldn’t tell the public this.

That they just shouldn’t let the cat out of the bag because society will crumble, and people will have less self-efficacy, and they will be less motivated to act morally and less motivated to act at all. [laughs]

It’s a very interesting debate to have. I don’t even know how you go about arguing those kinds of things, but it sounds like you’re interested in investigating those issues as well.

MARCEL: In a way, our data support that, and also the social-psychological data support this basic idea. I have to admit that I would question that you can withhold the information in a way, I think that’s not really the way to solve this problem.

But of course you have to be a little bit careful about the conclusions you draw from your data. And in my opinion there is not much evidence that free will doesn’t exist. There is also not much evidence that it does exist.

Of course these data seem to indicate that one should be a little bit careful about coming up with statements about free will.

But on the other hand, I also have to say that I think you can’t really completely question belief in free will and people. I mean, even people that would argue that free will doesn’t exist. I think in everyday life, they don’t really implement this knowledge, because you can’t, in a way.

You have to believe that your intentions are effective. If you wouldn’t believe that, yeah, I think yeah… suicide would be the only solution, in a way.

LUKE: [laughs]

MARCEL: So in this sense, you might be able to modulate these intentions about free will or belief in free will. But I think everybody in fact behaves as if free will exists.

If you lose this experience or conviction, then you are really in trouble, and we see specific pathologies where this is the case, in depression, or other pathologies where people have the impression that they can’t influence the world.

If they can’t control the environment, they have serious psychological problems. Because our belief that we can control our environment is extremely crucial for our health.

LUKE: Well Marcel, it’s been a pleasure speaking with you. Thanks for coming on the show.

MARCEL: Thanks again for inviting me.

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{ 50 comments… read them below or add one }

Leomar January 16, 2011 at 9:07 am


I’ll like to see the passages he provided in the experiment that presented that science disproved free will. Is that availiable ? It’s very important, as he says:

” .. one should be a little bit careful about coming up with statements about free will.”

I think if you put a fatalistic kind of statement, it can produce this kind of pesimistic outcome, but ones that just says our ordinary sense of free will, contra-causal free will, is wrong, then that won’t produce that kind of behaviors.

The experiment can also help to get to that kind of text. Also if you add to the passage that anyway you can have a rational morality, it would correct the result.

It seems that kind of fatalistic statement where used, as the link you provided says: “Surprisingly, the link between fatalistic beliefs and unethical behavior has never been examined scientifically — until now.”


John D January 16, 2011 at 12:23 pm

Apologies if this was discussed (I only scanned through the transcript and focused on the part discussed by Leomar above), but I’m wondering whether any studies have been done looking at how people’s behaviour is affected by reading statements about some of the paradoxes or problems associated with libertarian conceptions of free will e.g. the problem of luck (which I discussed on my blog last week). Does anybody reading this know whether such studies have been done?

It seems like all the studies done to date (at least the ones I have read about) have focused on how people respond to claims about determinism, fatalism and the illusion of free will. Surely, the other side of the equation needs to be examined as well.


Luke Muehlhauser January 16, 2011 at 12:40 pm

John D,

Good question! Alas, I don’t have an answer.


JS Allen January 16, 2011 at 4:18 pm

Great job with this interview, Luke. Absolutely fascinating topic.


Caleb O January 16, 2011 at 5:24 pm

although I have not read the complete transcript it seems to me that Marcel may have provided good reasons not for believing in freewill and that perhaps we could assume that are actions are either determined or random like everything else in the universe seems to be and that we don’t have any sort of libertarian free will. My basic reasoning is as follows:

1. If it is the case that our intentions obtain before person x is aware of those intentions
2. And if it is the case that our intuitions about freewill rely on when our intentions obtain when they do.
3. Then it is the case that our intuitions about freewill are mistaken.
4. Furthermore it seems as though the only reason we have for thinking that any persons have freewill is that they have the intuitions that they do.
5. But it is not the case that persons intuitions are correct
6. Therefore there is no freewill.

I am interested if there are any other arguments for free will other then our basic intuitions about it? At any rate I am quite excited to listen to the complete interview when I get the chance


Rob January 16, 2011 at 8:55 pm


I read an essay by Peter van Inwagen where he argues that free will is impossible. He then goes on to say that because he has such a strong personal experience of acting freely, then he must in fact be acting freely. So, free will is just a mystery, according to PvI.

As feeble as that is, it’s the best I’ve seen as far as the case for libertarian free will goes.


qapla January 17, 2011 at 5:13 am

Episode 62 of the Brain Science Podcast is an interview with Warren Brown, PhD, co-author (with Nancey Murphy) of
Did My Neurons Make Me Do It?: Philosophical and Neurobiological Perspectives on Moral Responsibility and Free Will.
This book was discussed in detail back in Episode 53, but this interview gave a chance to discuss some of the book’s key ideas with Dr. Brown. We focused on why a non-reductive approach is needed in order to formulate ideas about moral responsibility that are consistent with our current neurobiological understanding of the mind.
Tom Clark’s speech to the Freethought Association
BBC Horizon – The Secret You


qapla January 17, 2011 at 5:18 am

Minnesota Atheists podcast
Tom Clark’s short book Encountering Naturalism: A Worldview and Its Uses is a great introduction to naturalism. While the concepts may seem obvious upon reflection, the implications are enlightening.
Many people have difficulty understanding the concept of free will and why it doesn’t exist, often confusing “Free Will” and “Free Choice.”


Thomas January 17, 2011 at 5:40 am

Rob and Caleb,

libertarians argue that our first-person experience is some prima facie evidence for free will and that there is nothing in science that refutes that. That second part is important, because so often determinists just seem to assume that “science” somehow disproves our first-person experience of being free agents. But according to libertarians (and many others, too) this is not so. Libet´s experiements as well as Soon´s and others for example just show what libertarians knew all along: that our passive mental states are determined. But that does nothing to show that our active choices aren´t free (in an incompatibilist sense). The famous neuroscientist Wilder Penfield for example concluded after his research that “there is no place in the cerebral cortex where electrical stimulation will cause a patient . . . to decide”.

There is of course too the famous consequence argument, which purports to show that determinism is incompatible with moral responsibility. But obviously we are morally responsible; hence, determinism is false. There are also arguments which say that rational inference requires libertarian free will.

But the important thing that I as a libertarian want to say is this: there is nothing in science that refutes libertarian free will. And once you give the metaphysical principle of causal closure of the physical domain, the empirical case for determinism is gone (as Bill Hasker says). So I´d want to know this: assuming that I´m right in that science doesn´t give much evidence for determinism, what other reasons are there for being a determinist? The only reason that I can think of is that if something like materialism is true, then some kind of determinism seems to follow. But this argument is hardly convincing to non-materialists. So are there any non-circular arguments for determinism (assuming that science isn´t a strong one)?


Thomas January 17, 2011 at 6:26 am

Here is one paper arguing against reductionist interpretations of Libet´s and Soon´s experiments: http://philpapers.org/archive/BATMCA.1.pdf

Also for example Alfred Mele´s (not a libertarian) latest book Effective Intentions argues against the “science shows that free will is an illusion” -slogan. And there are many others.


Rob January 17, 2011 at 8:38 am


Is there any possible finding from science that could convince you that you do not have contra-causal free will? That is, is your belief in your own free will even on the table of things you might be wrong about?


Caleb O January 17, 2011 at 9:42 am

Hello Thomas,

Perhaps an amateur question: how do you go about defining passive and active mental states? And I am not to sure what you meant by

And once you give the metaphysical principle of causal closure of the physical domain, the empirical case for determinism is gone (as Bill Hasker says).

I suppose there is the famously old argument that either our acts are determined or they are random argument. I am not sure if it really works, though it does seem to be effective against people who point to certain aspects of quantum mechanics as evidence for freewill. You already mentioned the “argument for materialism”, you may be right in saying that such an argument won’t convince non-materialists, but perhaps it could convince property duelists. If one is some sort of property dualist one could affirm: that there is a strong causal relationship between physical events and mental events; physical events are determined; therefore mental events are determined as well. Or maybe a little differently; that mental events [I]emerge[/I] from physical events; physical events are determined; therefore you could infer that mental events are determined as well.


Caleb O January 17, 2011 at 9:44 am

Also Wilder Penfield is a bit old in the field of neurology.

Have you ever considered interviewing people like Micheal Martin or Theodore Drange Luke? Although they are not quite as active as they used to be in the philosophy of religion it would still be quite nice to hear some of their thoughts.


John D January 17, 2011 at 10:14 am

While Penfield’s research suggested that people didn’t think they consciously willed the actions that Penfield induced through direct stimulation, it is worth noting that Delgado performed similar direct stimulations that seemed to be accompanied by a feeling of conscious will. On page 46 of Daniel Wegner’s book The Illusion of Conscious Will, he cites the relevant passage from Delgado (1969).

Now, both Wegner and Delgado admit that this may not have been a direct feeling of conscious will but rather a post-hoc confabulation by the patient (i.e. a story was constructed by the patient to make them think the action was theirs) but either way it makes the appeal to Penfield’s experiment problematic.


Thomas January 17, 2011 at 11:46 am


of course scientific evidence could show I´m wrong. I tend to take both science and phenomenology seriously. To me these two just do not tell different stories, because I don´t think there is any good scientific evidence againts what my first-person experience tells me.

On the other hand, if an argument from reason which claims that active will is a necessary condition for reasoning is correct, then it is of course problematic to argue that scientific evidence shows that we do not have free will. But I´m not sure is such an argument correct..


Thomas January 17, 2011 at 12:10 pm


I´m an amateur too, but here´s how I understand it: when we are mental patients, things just “happen” to us as passive experiencers. These passive mental states include beliefs, desires and thoughts. But we are also sometimes mental agents, and this is when we make (actively) undetermined choices. So choices/decisions are active mental states.

By the causal closure -thing I meant to say that once you give up closure, then the empirical case for determinism is gone. This is because most of the empirical evidence for determinism assumes that physical events have only physical causes (this is known as ‘the principle of causal closure’). And when I said that it is “metaphysical”, I just meant that it is not a result of science, but rather it is a philosophical principle which just assumes physicalism. Here´s Hasker:

“…abandoning the causal closure of the physical domain completely eliminates the significance of physical determinism as evidence for a general thesis of determinism. Even if all purely physical processes are strictly deterministic (as many
indeterminists have been willing to concede), abandoning causal closure opens the way for indeterminism precisely where it is of most concern – in the thoughts, deliberations, and decisions of conscious beings.” (http://www.iscid.org/papers/Hasker_NonReductivism_103103.pdf)

Ok. I think you mean the problem of luck for libertarianism? I´m not convinced by it, because an undetermined free choice can be explained teleologically in terms of reasons and puposes, and then it´s not just a matter of “luck”. (On the other hand, much smarter folks than me find the argument convincing, like PvI.)

And you are right that the materialism -argument is a good one for property dualists, but property dualists are substancematerialists. So what I meant was that this argument is worthless to (substance)dualists and theists (like myself).

John D,

thanks for the information.


Kyle Key January 17, 2011 at 3:02 pm

Thomas: “But we are also sometimes mental agents, and this is when we make (actively) undetermined choices.”
If the “choice” is undetermined, what is it based on? Later in your post you say that choice can be explained in terms of reasons and purposes; are you further implying that “reasons and purposes” aren’t merely synonyms for “beliefs, desires and thoughts[, etc.]” that make up your “passive mental states” category? If they are synonyms, then how can choices be nondeterministically explained in terms of passive mental states? If they’re different, then I’ll need some help from you regarding what “reasons and purposes” are.
There are three options, as I see the situation: one can say that (1) choices are entirely undetermined and thus random, in which case, why do we even need to talk about beliefs, desires, etc.?; (2) choices are somewhat determined, but not entirely, in which case, some explanation of the degree to which decisions are undetermined would be helpful in explaining your case; or (3) choices are a fun illusion, because our mental activities are entirely determined, which is my selection, but which you obviously aren’t a fan of.

“most of the empirical evidence for determinism assumes that physical events have only physical causes”
It seems that you’ll want to say (2), with an appeal to a non-physical cause of our physical brain states, which of course, very few people here will agree with. Could you give an example of a non-physical cause of a physical event? The problem is that anything you say (that I can currently think of) will be seen as a post-hoc rationalization for theism. And clearly I don’t view the evidence for determinism being merely an assumption that physical events only have physical causes, but rather that the only evidence we have points to that conclusion.


Rob January 17, 2011 at 4:44 pm


Can you please describe an experiment that would convince you that you do not have contra-causal fee will? Thanks.


Thomas January 17, 2011 at 11:46 pm


It seems that you’ll want to say (2), with an appeal to a non-physical cause of our physical brain states, which of course, very few people here will agree with.

Yes, I do think that libertarian free will requires dualism. In my view we are souls who have a basic power to choose in terms of reasons. And yes I know, very few people here will agree with this, but so what? My earlier point was that, contra the claims of many non-libertarians, there is nothing in science that refutes dualism and libertarianism.

Could you give an example of a non-physical cause of a physical event?

Yes. I am now moving my fingers when typing this comment. But I am a non-physical soul, and my choice to move my fingers in this order causes my physical neurons to fire which then causes the movements of my fingers. Circular? Surely, but my point is that if one has some reasons to believe that he is a non-physical soul, then he has reasons to believe that some physical events have non-physical causes (human agency). Your claim that “the only evidence” point to determinism is to me equally circular, because that just assumes that we just aren´t souls who have a power to choose.


Thomas January 17, 2011 at 11:51 pm


yes I can describe an experiment which would at least give me big doubts about free will. This comes from a recent book, The Soul Hypothesis, edited by Baker and Goetz. I highly recommend this one to everyone who thinks that dualism is just “unscientific”. I don´t have time to look and describe the experiment from the book now, but I´ll do that later.


Thomas January 18, 2011 at 2:38 am


you can read the possible experiment by Baker and Goetz here: http://www.amazon.com/Soul-Hypothesis-Investigations-into-Existence/dp/1441152245/ref=sr_1_1?s=books&ie=UTF8&qid=1295345637&sr=1-1#reader_1441152245 (“Testing A Soul Hypothesis”, p. 14-16)

Unfortunately the preview doesn´t show pages 17-18, so here´s what they say there. Baker and Goetz admit that this kind of an experiment haven´t been done and it´s unsure if it could be done. Nevertheless there are more modest versions of it, like the Penfield-experments which I already mentioned. The crucial point is that the libertarian predicts that a neuroscientist cannot make a patient choose in a way that the choice feels voluntary, and Penfield´s experiments show just this.

Baker and Goetz also mention neuropyschiatrist Jeffrey Schwatrz´s argument according to which patients with obsessive compulsive disorders can choose to redirect and focus their attention on ways of living that prevent fulfillment of their OCD urges. Baker and Goetz continue: “If he is right, then this is a tangible, clinically proven case that provides support for the hypothesis that the soul has the non-deterministic freedom to causally affect (even overcome) the brain.” (19)

So what kind of scientific evidence would be evidence against free will? If it could be shown that “voluntary” choices actually have deterministic causes or even more modestly, if a neuroscientist could make a patient to choose in a way that this really feels voluntary to the patient.


Rob January 18, 2011 at 4:55 am


Thanks. I’ll consider reading Baker Goetz. You are more interested in the inner experience of the subject than I am though.

Do they explain how the soul evolved? Do dogs have souls? What about beetles? Computers?

I think any definitive experiment would require backward in time time travel.


Thomas January 18, 2011 at 5:17 am


one of the lessons of the book is that there are many different soul hypotheses. But one option which is recommended in the book at least by Hasker and Zimmerman is Emergent Dualism. According to this one the soul emerges from the brain, so animals with similar brains than humans surely have souls, too. One advantage of emergent dualism is that it takes neuroscience and the mind/brain relationship more seriously than traditional Cartesian dualism. The best book on this version of dualism is Hasker´s The Emergent Self, though Hasker has a decent chapter on it in Baker & Goetz, too.


John D January 18, 2011 at 8:10 am


Delgado’s experiments would seem to potentially disprove the soul hypothesis according to the Baker and Goetz criterion that you outlined above. Like I said, Delgado directly stimulated a patient’s brain, this caused the patient to turn their head to side. When asked why they turned their head to the side, the patient offered some reason or justification for this movement. They did not claim, as was the case in Penfield’s experiments, that the experimenter had made them do it. The action felt like it was their own.

Now admittedly Delgado didn’t directly ask: did you voluntarily turn your head to the side? But still, it seems like his experiment shows that people can be readily causally directed to perform actions that they think are theirs but really aren’t.

Does this mean the soul hypothesis is now disproved?


Thomas January 18, 2011 at 11:13 am

John D,

Like you pointed out in your last comment, “both Wegner and Delgado admit that this may not have been a direct feeling of conscious will but rather a post-hoc confabulation by the patient (i.e. a story was constructed by the patient to make them think the action was theirs).”

So I´m a bit skeptical. If it really is the case that Delgado´s experiment shows what you claim they might show, then I think that these experiments count against the soul hypothesis, though they do not “disprove” it. But I have to look at this more carefully. Thanks again for letting me now about Delgado.


cl January 18, 2011 at 12:58 pm

…we are only starting to understand the networks that are involved in specific tasks. … we don’t really have an understanding of the information flow in the brain. … in more complex domains like research on cognitive control or intentional action, we don’t really have a good understanding how informations are transferred between different brain areas. … Yeah. I absolutely agree. First of all, I do not really think that neuroscience will solve the old philosophical problem whether free will exists or not. And I’m not even sure whether any science will solve this problem.

I don’t cite any of that to thumb my nose at Marcel Brass – whom I respect. Rather, I cite that to thumb my nose at those who would bastardize research in neuroscience to make ludicrous claims like, “neuroscience has falsified Christianity,” or, “neuroscience has falsified free will.” As Marcel elucidates,

…of course you have to be a little bit careful about the conclusions you draw from your data. And in my opinion there is not much evidence that free will doesn’t exist. There is also not much evidence that it does exist.

What a refreshing does of non-partisan honesty. Cheers to you, Marcel Brass.


Kyle Key January 18, 2011 at 5:26 pm

What’s a soul? It sounds like a synonym for “mysterious magic that I use to keep my theism from immediately dying.”

“Your claim that “the only evidence” point to determinism is to me equally circular, because that just assumes that we just aren´t souls who have a power to choose. ”
If by “equally circular,” you mean something like, “holds to Occam’s razor and explains the topic better with fewer entities,” sure. And by “assumes…,” you mean, “doesn’t make things up post-hoc in a frantic effort to support unevidenced theistic beliefs.” (1) Humans aren’t made of any special or unique atoms, quarks, molecules, subatomic particles or anything else–we’re composed entirely of the same stuff that makes up the rest of the universe. (2) Humans have never been observed to break the laws of physics. The same deterministic laws that govern the matter outside of our bodies don’t stop governing that exact same matter inside our bodies. Until you can provide good reason to think that (1) or (2) is false, you have no case. If you’d like to assume, for the sake of your theism, that souls and reasons and purposes (which you failed to explain as being any different than beliefs, thoughts, or desires, i.e. various physical constituents of the brain governed by the deterministic laws of the universe) and a power to choose are also required to explain our “choices,” be my guest, but you’re digging larger holes with every post rather than presenting even a quasi-viable alternative to determinism.


cl January 18, 2011 at 6:58 pm

So Rob: are you ready to clarify and explain your opinion that neuroscience has falsified Christianity? You told me to wait for this discussion, so I did.


Luke Muehlhauser January 18, 2011 at 7:10 pm


Neuroscience falsifies dualist theories of the “soul” and mind in the same way that modern electrodynamics falsifies the Zeus hypothesis of lightning. Of course you can always say “Well, okay, but behind the electrodynamics it’s still Zeus,” but this should not impress anyone. If your “out” is to say that it’s still possible that magic is behind the physical processes we now understand, then there is nothing that can be “falsified” in that sense. Which is exactly the problem with magical explanations in the first place.


Rob January 18, 2011 at 8:01 pm


Some forms of Christianity depend on substance dualism and/or contra-causal free will being true. Many findings in neuroscience strongly imply that substance dualism and/or contra-causal free will are not true. Therefore . . .

My claim is not unique or profound.


Rob January 18, 2011 at 8:44 pm


Also, many folks within Christianity and other supernaturalisms perceive the threat of neuroscience as well. The garbage put out by DiscoTute goon Michael Egnor comes to mind.


cl January 18, 2011 at 10:51 pm

I know you get good kicks out of laughing at me, but, you guys are hilarious sometimes. Talk about double standards.


Neuroscience falsifies dualist theories of the “soul” and mind in the same way that modern electrodynamics falsifies the Zeus hypothesis of lightning.

Puh-leeze! Do I even have to tell you that this is a bare assertion? Explain how, don’t assert nudely.


Many findings in neuroscience strongly imply that substance dualism and/or contra-causal free will are not true.

Ah, gotcha… “many findings.” Congratulations! Who cares about precision when one can always swing a 2×4, eh?

Also, many folks within Christianity and other supernaturalisms perceive the threat of neuroscience as well.

OMG, that’s like, so relevant! I’m definitely becoming an atheist, tonight.


Rob January 18, 2011 at 11:05 pm


I’ve noticed you have difficulty following the natural flow of a conversation, and are incapable of comprehending how one idea follows from or is connected to another. In other words, having a reasonable conversation with you is not possible.


Luke Muehlhauser January 18, 2011 at 11:43 pm


Yeah, that’s been my experience with cl, too. Many (most?) of cl’s responses are given as if the quoted passage was given in a different sense or context than it actually was. I feel like the subject changes with almost every reply.


Thomas January 19, 2011 at 2:58 am


that was a strong response. First, you can say that a soul is “mysterious magic”, but this is hardly an argument. The soul is the thing that is a subject of experience. We know something about matter and the dualist thinks that the matter is a poor candidate for being the subject of experience. So we need something non-physical. Call it “a soul”. Most human beings in history have believed in something like a soul. And by the way, I could be a materialist and a theist, like Peter van Inwagen, and the Christian tradition allows this because eternal life is spent in a material (resurrection)body. So I´m not a dualist because I´m a theist. I´m a dualist because I think that material stuff is not the kind of stuff that can be a subject of phenomenology and exercise human agency.

What about your (1) and (2)? Well, with respect to (1), humans (and non-human animals) still have this thing called “consciousness” so maybe that gives evidence that there is something non-material in human beings, given that the reductionist strategies fail and eliminativism is just giving up. By the way, I´m in a pretty good company here since many philosophers of mind (Kim, Strawson, Horgan, Burge, Chalmers, Levine, Nagel, BonJour, etc.) these days think that you just can´t reduce phenomenological consciousness. And thus your claim that “we’re composed entirely of the same stuff that makes up the rest of the universe” egregiously begs the question. And (2) does the very same thing. Laws of nature are conditional. If such and such is the case, this will happen and they apply to closed systems. But if we are souls who have a power to make choices, then of course the universe is not closed and thus this doesn´t “brake” the laws of physics. It just means that humanly free agents have a power to make choices, not determined by physics. Your claim that this has never been observed just begs the question. If I´m right, we observe that all the time. In an earlier comment I cited Hasker when I claimed that the empirical case for determinism rests on an assumption of the principle of causal closure. Your comment is a case in point. Give up the closure, and the empirical case for determinism is gone. And I don´t know any non-circular arguments in favour of the closure.


Thomas January 19, 2011 at 3:06 am

Rob: “Many findings in neuroscience strongly imply that substance dualism and/or contra-causal free will are not true.”

My point here has been that this is actually not the case. I´d be grateful if you shared some of these findings.

And by the way, I´m not a dualist and a libertarian because I´m a theist. Rather, one reason I´m a theist is because I think that some kind of dualism and libertarianism is true. So I think that this discussion can be made without any reference to theism or religion. In fact, there are substance dualists who are non-theists, like Karl Popper and even some naturalists have strong libertarian sympathies, like John Searle.


Thomas January 19, 2011 at 3:17 am


I actually tend to agree with cl on your last comment. Your analogy just presupposed that materialism has explained everything there is to be explained. Well of course if this were the case then dualism would be an unnecessary assumption. But the issue is that materialism actually doesn´t save the phenomena. So you can´t just assume that materialism is true and then have a laugh at dualists. You have to give some arguments how materialism could be true. And again, substance dualism looks a lot better if there is something non-material in consciousness and here I think we are in a good company. Many philosophers of mind think that reductionism and eliminativism is just false. Phenomenological consciousness exists and you can´t reduce it. I´d like to see you giving your Zeus-analogy at this point to someone like Strawson or Chalmers or Horgan or Levine.


Rob January 19, 2011 at 7:04 am


The massive data we have on brain injured patients relegates substance dualism to the dust bin of history. Sure, the dogmatic dualist can just say something like “no, the brain is like an antenna or receiver for the soul blah blah blah”. These moves are idiotic; Luke’s Zeus/lightning analogy holds. The Libet and Delgado type finding dispense with free will.

Since you are now dropping the names of famous alleged authorities . . . why is it, do you suppose, that the overwhelming majority of neuroscientists are non-dualists?


Thomas January 19, 2011 at 8:16 am


“The massive data we have on brain injured patients relegates substance dualism to the dust bin of history.”

This is just silly. First, the radical dependency of brains and our mental lives is not a result of modern science. Humans have known this for thousands of years. Second and more importantly, I already mentioned Emergent Dualism. I just can´t understand why brain damages undermines Emergent Dualism at all. The soul emerges from the brain, so it´s of course radically dependent on it. This is by the way why we need philosophers as well as scientists; scientists tend to interpret the empirical data rather naively, like you have just done. Brain damage is a problem for traditional Cartesian Dualism, maybe, but there are other types of dualism, too. This kind of stuff just shows to me that the critics of dualism usually really don´t know what they are criticizing of. This is typical among professional philosophers, also, who usually just make a strawman version of dualism, then laugh at it and leave it there (case in point: Dennett). So before making assertions like above, maybe you should read what dualists are actually saying. (For example, Hasker´s The Emergent Self, Swinburne´s The Evolution of the Soul, Taliaferro´s Consciousness and the Mind of God, Unger´s (who is a naturalist and a substance dualist) All the Power in the World or maybe Robinson´s Objections to Physicalism. Even the philosophical Encyclopedia entries (Stanford, Routledge) to dualism are quite positive these days, interestingly.

And I have already argued that Libet´s experiments do nothing to undermine libertarianism and Libet himself urged people not to make too radical conclusions about this experiments. As for Delgado, Penfield´s experiments gave just the opposite conclusions, so I´m a bit skeptical about Delgado. So if this is the justification for the “science debunks dualism and free will” -stuff, then I´m not impressed at all.

There have been some very famous neuroscientists who have been substance dualists, like Penfield and Eccles. But I don´t know why so many scientists these days are materialists. Probably one reason is the spirit of the age. But I´m happy that we have some very good philosophers of mind who, albeit naturalists, acknowledge that finding a neural correlate of consciousness is not the same thing as reducing conciousness to


Rob January 19, 2011 at 8:48 am


I should have qualified my criticism to substance dualism. I have no problem with emergent dualism. If you want to call that emergent property a “soul”, fine.

So computers will one day have souls. In my experience, most Christians find that notion objectionable. Can computers sin? Will they be in heaven?


Rob January 19, 2011 at 8:51 am


Wait, I did qualify my criticism to substance dualism, so you bringing up emergent dualism is a rather empty response.


Thomas January 19, 2011 at 9:11 am


I didn´t mean property dualism, I meant emergent substance dualism! This is the theory that Hasker presents in The Emergent Self, which is a great book. The self, the subject, the soul emerges from the brain. This is much more than mere property dualism. So there are a variety of substance dualisms out there, and traditional Cartesian Dualism is a minority position among substance dualists these days.


cl January 19, 2011 at 9:18 am

Luke / Rob,

Nice excuses. Nice double standards. You know damn well that if I said, “neuroscience falsifies materialism” you’d be all over me demanding that the burden of proof be met. If you don’t want to back up your claims, then, don’t. Seriously. This “oh let’s make a bold claim and then wuss out when called on it” thing is just stupid. You guys are the ones making the claim, you retain the burden of proof, so man up and take some responsibility for this crap you’re spouting in the name of science and rationalism. This is utter hypocrisy.


I actually tend to agree with cl on your last comment. Your analogy just presupposed that materialism has explained everything there is to be explained.

Yeah, that’s pretty much the status quo for the “rationalists” around here. I don’t know if you’re new, but I’ve been here for almost two years now, and, it’s the same every time Luke gets backed into a corner: last out at the interlocutor instead of defending his claim head on, or, whine about lack of time, or, just flat out fail to respond at all. I’ve provided links to back that up so many times it’s ridiculous.

That said, I’ll let you field Rob’s “arguments,” then provide supplementary commentary as I see fit.


Thomas January 19, 2011 at 9:21 am

Rob, maybe you can check this post by Victor Reppert. I find it useful in this context.



Luke Muehlhauser January 19, 2011 at 10:23 am


You’ve completely missed my point.


Thomas January 19, 2011 at 11:08 am


did I miss your point? How your analogy did not just assume the truth of materialism?


Kyle Key January 19, 2011 at 2:42 pm

Glossing over the argumentum ad populum (“Most human beings in history have believed in something like a soul.”) and the appeal to authority (“By the way, I´m in a pretty good company here since many philosophers of mind…”)–which, even if you’re going to say that they aren’t fallacious in this context, make no contribution to your argument–there’s nothing of substance (BA-DUM-CHING) in your reply.
I’ve specifically asked for explanations of “reasons and purposes” twice, and “souls” and “a power to choose” once, all of which have been met with little more than “Well, materialism doesn’t work!”
You seem to object to materialism on the grounds that it alone cannot explain consciousness or qualia, but have only a series of “well-I-can-tell-you-what-they’re-nots” to further muddy the issue. You “explain” a vague concept by offering even vaguer terms (soul, reasons and purposes, a power to choose), accuse materialists of begging the question for not assuming the viability of the impotent concepts you’ve pulled out of thin air, and strangely, I’m not interested in what you’re selling.


Thomas January 19, 2011 at 11:15 pm


I will be the first one to admit that my positive case for dualism is very insufficient. My comments here have been thoroughly defensive. I have argued that there is nothing in science that refutes free will or dualism and also that phenomenal consciousness puts materialism in trouble. That´s it. This has been my only goal. I have then given a sketch about emergent substance dualism, but I haven´t got the resources to defend this positive case properly. So I´m not “selling” anything to you, I´m just defending non-materialistic and non-deterministic alternatives against popular but bad arguments and claims.

I think that if some event is ultimately explained teleologically in terms of reasons and purposes, then this explanation cannot be causal in nature. That is, teleological and causal explanations are fundamentally different and irreducible explanations. That´s why an undetermined choice which has a teleological explanation is essentially uncaused. This is called non-causal libertarian agency and this view is defended sophisticatedly by Stewart Goetz in Freedom, Teleology, and Evil (Continuum, 2009). Now, I´m well aware that this is controversial and that you´re not going to be impressed. But like I said, my main point here has been only defensive; I admit that I can´t give a detailed positive case.


cl January 24, 2011 at 11:33 pm


You’ve completely missed my point.

It’s been a week already! Why don’t you quit making excuses, take ten minutes, and answer Thomas? I’m purposely trying to stay out of this. You can’t use all of your stock excuses with Thomas, so, will you answer him, Mr. Oh I’m So About Logic & Reason? If not, what’s your excuse for not answering Thomas? No time? Surely you can’t denounce Thomas as a troll, right? What gives? Tell you what: I’ll give you a few more days, perhaps another week or three, and then, if you still fail to take responsibility for your claim, I’ll elaborate on mine, including a concise-yet-positive case for dualism.

Don’t get me wrong, as much as you irk me at times, I still respect you, I’m only mocking you because I know you’re receptive to mockery, and you really aren’t being consistent here. So, man up already, will ya? Brave dudes get more panty [source].


matteo September 20, 2011 at 12:47 pm

Reading the part of the interview on the experiment about beliefs… we can have the answer about free -will problem. It exists… but not in the way we think it exists.
Consciousness influences our brain . SHE isn’t epiphenomenal… and what we think about ffree will is a little bit wrong…but fre willl exists.
Free will is our capacity ti make choice anticipating the future… not in taking glasses or pushing buttons… and it’s obvious!! if I had to do something now I can’t stop myself to doing that, but if I have to choose about my future, I’m free.


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