Podcast Episode 11 - The Future Like Ours Argument

Back by popular demand....(download here)

Not quite. I actually recorded this over a month ago, but I added a new bit at the start and hope to do some more over the coming weeks. This one is about Don Marquis famous future like ours argument, which is generally considered to be the most significant secular argument against abortion. Should be of interest to anyone looking at applied ethics or, more generally, at the structure of philosophical argumentation.

The Tooley-Marquis dialogue that I refer to during the podcast is here.

Posts on the Philosophy of Mind

Regular readers will know that I recently completed a series of posts on the philosophy of mind. All were based on material found in William Jaworski's book Philosophy of Mind: a Comprehensive Introduction. The following is a list of all these posts.


1. Philosophy of Mind: Mapping the Theoretical Space

2. Substance Dualism (Part One): The Basic Argument

3. Substance Dualism (Part Two): Criticisms of the Basic Argument

4. Substance Dualism (Part Three): The Problem of Other Minds

5. Substance Dualism (Part Four): The Problem of Interaction

6. Substance Dualism (Part Five): Explanatory Impotence

7. Mind-Body Physicalism (Part One): Argument from Past Explanatory Success

8. Mind-Body Physicalism (Part Two): Hempel's Dilemma

9. Mind-Body Physicalism (Part Three): The Knowledge Argument

10. Mind-Body Physicalism (Part Four): Absent and Inverted Qualia

The Ethics of Euthanasia (Part Two)

(Part One)

This post is the second in a short series on the ethics of euthanasia. The series follows the pair of essays in the book Contemporary Debates in Applied Ethics. Right now, I am looking at Michael Tooley’s “pro” euthanasia essay. In part one, I outlined, in some detail, Tooley’s basic argument. In this part, I’ll consider Tooley’s second argument, as well as his views on the legalisation of euthanasia.


1. From Passive to Active Euthanasia
To understand Tooley’s second argument we need to bear in mind the different forms of euthanasia. As you recall from part one, particular instances of euthanasia can vary along two dimensions: (i) the voluntary-involuntary dimension; and (ii) the active-passive dimension. The first of these dimensions is concerned with the attitudes of the person being euthanised to their death (did they consent to it or not?), while the second is concerned with the type of assistance offered to that person (does a third party act to bring about their demise or is their demise brought about through omission?).

The most ethically contentious form of euthanasia is the voluntary active one. This form of euthanasia arises whenever a person A performs some action which has as its direct intention the killing of another person B, and B consents to this. Contrariwise, the voluntary passive form of euthanasia is relatively uncontentious. Most people seem to think it would be okay for B, in certain circumstances, to forego life-preserving treatments. The asymmetrical reactions to these forms of euthanasia opens up an intriguing possibility: if we can convince people that there are no morally significant differences between the active and passive forms of voluntary euthanasia, then perhaps we can convince them that euthanasia is morally permissible.

This is exactly what Tooley’s second argument attempts to do. It tries to show that there are no good grounds for thinking that two cases are ethically different. Let’s see how he makes his case.


2. The Difference between Killing and Letting Die
Tooley starts by offering the following argument:

• (1) Voluntary passive euthanasia is not morally wrong in itself.
• (2) Intentionally killing a person and intentionally letting a person die are, in themselves, morally on a par.
• (3) The only intrinsic difference between voluntary active euthanasia and voluntary passive euthanasia is that the former is a case of killing, and the latter a case of letting die.
• (4) Therefore, voluntary active euthanasia is not morally wrong in itself.

Premise (1) is likely to be accepted by most people, and premise (3) is just an implication of the definitions of active and passive euthanasia. This means that premise (2) is where the controversy might be thought to lie.

Is it really true to say that intentional killing and intentional “letting die” are morally equivalent?

Some philosophers are likely to argue that there are important moral differences between the two cases. In making their argument, they might appeal to the famous thought experiments involving organ donation. For instance, consider the following. You are doctor in a hospital with two patients, both of whom need organ transplants to survive (say one needs a kidney and the other needs a heart). As luck would have it, a healthy person who is a perfect match for both patients walks into your hospital ward. If you kill the healthy person and harvest their organs, you can save your two patients. Should you do it? Most people say “no” but this is puzzling if there’s no moral difference between killing and letting die. After all, if there were no moral difference then surely letting two patients die would be worse than directly killing another?

Tooley thinks we can skirt these difficulties by first acknowledging the following asymmetry principle which, presumably, motivates the objection to premise (2):

(A) The property of killing a person and the property of allowing a person to die are, other things being equal, wrong-making properties of actions, but the former is a weightier wrong-making property than the latter.

See what we’ve done here? We’ve acknowledged that killing and letting die are morally undesirable, but we’ve also accepted that the former is worse than the latter. This can account for our reaction to the organ donation case.

But this asymmetry principle is problematic in the present context. As David Boonin argues, if principle (A) is true, then the following more general principle ought to be true:

(B) Both the property of intentionally causing a harm, and the property of intentionally allowing a harm to occur are wrong-making properties of actions, but the former is a weightier wrong-making property than the latter.

Principle (A) would actually be derivable from (B) since (B) expresses the more general rule that harming is morally bad. The problem this creates is the following: in the euthanasia case the claim is that killing a person is not actually a harm to them but is, in fact, a benefit. This is why I included the clause “other things being equal” in my formulation of principle (A): the point being that in euthanasia cases “other things” (namely, the relationship between death and harm) are not equal.

We can go further with this line of thought by noting that (B) would seem to have an obvious corrollary:

(C) Both the property of intentionally causing a benefit and the property of intentionally allowing a benefit to occur are right-making properties of actions, but the former is a weightier right-making property than the latter (or, at a minimum, is at least as weighty a right-making property as the latter).

From which could be derived the following revised version of premise (2):

• (2*) Both the property of killing a person, when the killing benefits the person, and the property of allowing the person to die, when allowing the person to die benefits the person, are right-making properties of actions, and the former is at least as weighty a right-making property as the latter.

When plugged back into the argument given above, (2*) allows us to reach the same conclusion. But is it any less objectionable than the original version?



3. The Revised Form of Premise 2
Tooley thinks there is one plausible line of objection to the revised version of premise (2). This line of objection holds that the property of killing a person, even when the killing benefits them, cannot be a right-making property of an action since the direct killing of an (innocent) person is always morally wrong in and of itself. The “innocent”-caveat here is a concession to those who think that under certain conditions it is morally good to inflict capital punishment on a guilty person.

To those who mount this objection to (2*) we must ask: what basis is there for thinking that killing innocent persons is morally wrong in and of itself? There are two possibilities here (according to Tooley). Appealing to axiology, we could argue that the existence of innocent persons always makes the world a better place than it would be if they failed to exist (2.1). Or, appealing to the notion of rights, we could argue that all innocent persons have a right to life and so any violation of that right would be morally wrong (2.2).

The appeal to axiology faces two objections. First, if it is true, then intentionally refraining from bringing persons into existence is also morally wrong in the exact same degree. This is implausible (2.3). Second, looking at cases of people suffering considerable pain due to incurable illness, the proponent of the axiological appeal must believe that their continued existence is a net benefit to the world. But then should they not also hold that the failure to bring into existence a person who will live a life of considerable pain is morally bad? Again, this seems very implausible (2.4).

The appeal to rights is also problematic. For starters, people can, in general, waive their rights (2.5). What’s more, the claim that the death of those who are suffering considerable pain due to incurable illness violates their rights is likely to be false. Why is this? Well, consider that there are two plausible theoretical bases for rights, either (a) rights protect individual interests or (b) rights protect freedom of choice. But in the voluntary euthanasia case, the claim is that death is either (i) in the person’s interests or (ii) something they desire for themselves. Therefore, on neither account is voluntary euthanasia a violation of individual rights (2.6).

That gives us the following completed argument map.

4. The Legalisation Debate
Through his two arguments, Tooley feels he has made the case for the moral permissibility of voluntary active euthanasia. But just because something is morally permissible does not entail that it should be legalised. For example, some people think that, under extreme circumstances, interrogative torture is morally permissible. But the same people do not necessarily think that the legal ban on torture should therefore be relaxed. Laws alter people’s incentives and these alterations may not be morally desirable. So before pronouncing on legal policy, Tooley considers three objections to the legalisation of voluntary active euthanasia.

The first objection comes from Yale Kamisar. He argues that if voluntary euthanasia is legalised, some people will consent to being killed in cases in which their death is actually contrary to their own interests. Tooley is pretty quick in his dismissal of this argument. He argues that, unless the person is emotionally or psychologically disordered, there no reason to think they will fail to appreciate good reasons for their continued existence if such reasons exist. Also, he argues that this objection fails to distinguish between the active and passive forms of voluntary euthanasia. So if it’s a good objection to legalising the active form, then it’s also a good objection to legalising the passive form. That’s a problem for Kamisar since, according to Tooley, he accepts the latter. So much the worse for Kamisar, I guess.

The second objection appeals to the notion of a slippery slope: if we legalise voluntary active euthanasia, what’s to stop us from legalising other undesirable things such as involuntary euthanasia? Kamisar also makes this argument. He justifies this by pointing out that advocates of voluntary active euthanasia often think that certain forms of non-voluntary euthanasia should be legalised. He also points to the historical experiences in Nazi Germany and suggests that some of the problems there were attributable to an initial acceptance of the proposition that there is such a thing as a life not worth living. And from there it was but a short slide down the slippery slope to racial extermination.

There are many things that could be said in response to this. We can start by pointing out that there is a distinction between non-voluntary and involuntary euthanasia and that acceptance of the former would not logically entail acceptance of the latter. Turning to the Nazi case, we become embroiled in a dispute over historical causality. The claim that there was a slippery slope from the acceptance of one proposition about the worth of life to policies of racial extermination is certainly debatable. Some would argue that the ideology of racial purity and supremacy predated the acceptance of the claim that some lives are not worth living. And that this is a more likely cause of the extermination policies. Whatever the case may be, it seems that the Nazi experience is likely to have multiple, historically contingent causes, most of which will not apply to modern societies.

Furthermore, in response to the slippery slope argument, we can point to empirical evidence suggesting that the slippery slope will not arise. The best set of evidence comes, of course, from the Netherlands which has legalised voluntary active euthanasia. The evidence from the Netherlands is controversial. Some (including Callahan, who we’ll talk about the next time) argue that the Dutch experience actually does provide evidence of a slippery slope because there have been cases of involuntary euthanasia there. Tooley disputes this, however, because it fails to contrast the situation in the Netherlands with the situation in countries which have not legalised voluntary euthanasia. He argues that when you contrast it with such a country (he uses the example of Australia) you find that there are more cases of involuntary euthanasia in the other countries.

I’m a little bit wary of this empirical evidence because Tooley only compares figures over the years 1995-1996 (and he’s basing this on analyses done by others). I haven’t read this evidence and I haven't read any countervailing evidence either. Nevertheless, there is an interesting point here: regulation of an activity can sometimes lead to fewer rights-violations than non-regulation because people are suddenly made accountable for decisions which were previously carried out under the radar of the law.

The third and final objection to legalisation is this: there is uncertainty about the form that legal regulation should take. Should there be complex and stringent guidelines for those who carry out voluntary euthanasia? Or should there just be some general principles? If we opt for the former, then some people who might benefit from euthanasia might be excluded. And if we opt for the latter, rights might fail to be protected.

Tooley’s proposal is this: First, we follow James Rachel’s suggestion and make voluntary active euthanasia a defence to a charge of murder or manslaughter (like self-defence). And second, we combine this with rather conservative and stringent regulation. The former would allow for a certain degree of flexibility, while the latter would protect against abuses.

I have no idea whether this dual regime would work. My preference would be for complex and stringent guidelines since, acknowledging that errors will be made, I think we should err on the side of preserving life rather than ending it.

This brings us to the end of Tooley's essay. In the next part, we'll look at the anti-euthanasia essay by Daniel Callahan.

The Ethics of Euthanasia (Part One)

The book Contemporary Debates in Applied Ethics recently found its way into my hands. It's a decent collection of essays on topics ranging from abortion, to capital punishment, to world hunger. As might be expected from a debate book, it adopts a “pro” and “anti” format. In other words, there are eleven pairs of essays with each pair consisting of an essay defending a proposition and another one opposing the same proposition. Unfortunately, the interplay between the essays isn’t perfect and, as per usual, the authors occasionally talk past one another. Still, the standard of discussion is high and it makes for rewarding reading.

Anyway, I thought I might share some of the book here on the blog since the argumentative back-and-forth of the essays fits well with the kind of analysis I usually undertake. First up will be the pair of essays on euthanasia. The pro essay is written by Michael Tooley; the anti essay is written by Daniel Callahan. I’ll go over Tooley’s essay first (it might take a few posts), then I’ll turn to Callahan’s essay.

In this post, we’ll go through some conceptual distinctions and we’ll look at Tooley’s basic pro-euthanasia argument. I should clarify at the outset that Tooley isn’t necessarily “pro” euthanasia. He just thinks it isn’t morally wrong. In this respect, his argument might be thought to resemble the pro-choice position on abortion.


1. The Euthanasia Landscape
Tooley adopts the following definition of euthanasia:

“Euthanasia” = Any action where a person is intentionally killed or allowed to die because it is believed that the individual would be better off dead than alive — or else, as when one is in an irreversible coma, at least no one is worse off.

So understood, “euthanasia” captures a rather broad range of activities. Certainly much broader than the range of activities that Tooley’s opponent Callahan thinks fall within the rubric of “euthanasia”. Callahan defines euthanasia as the direct killing of a patient by a doctor. Such a definition is, as Tooley notes, narrower than his in at least three ways. First, it excludes killing by means of omission ( e.g. withdrawing life support). Second, it excludes methods of killing that are indirect (Tooley cites the example of a morphine dose which leads to respiratory failure but which is directly intended to reduce pain). And third, it limits itself to patients. Tooley thinks these limits are morally irrelevant. More on this in a later post.

For now, we need to be a little bit more discriminating in our conceptualisation of euthanasia. In particular, we need to pay attention to two dimensions along which particular instances of euthanasia can vary.

The first of those dimensions captures the distinction between voluntary, non-voluntary and involuntary forms of euthanasia. An instance of euthanasia is voluntary if the person who is euthanised either consents to or requests their death. An instance of euthanasia is non-voluntary if the person who is euthanised does not have the capacity to communicate their desires (e.g. as in a coma). And finally, an instance of euthanasia is involuntary if the person is euthanised against their will.

The second dimension captures the distinction between passive and active forms of euthanasia. There are different ways of understanding this distinction. According to one, the distinction is between killing someone by omission ( i.e. by doing nothing) or by performing some act. Alternatively, the distinction is between the primary causes of death. If the primary cause of death is human action, then we have a case of active euthanasia. And if the primary cause of death is disease or injury, then we have a case of passive euthanasia.

With those dimensions in place, we can construct the following grid.

The grid captures all the possible forms of euthanasia. We can assign moral statuses to each of these forms. I note that most people think that passive voluntary euthanasia is morally permissible, i.e. they think its okay for someone to refuse to undergo life-saving treatment (in certain cases). I also note that many people think that passive non-voluntary euthanasia is morally permissible, i.e. a family can withdraw life-support from a relative who is in a persistent vegetative state. What we’re interested in here is whether active voluntary euthanasia is morally permissible.


2. Making The Case for Active Voluntary Euthanasia
If you have any familiarity with Tooley’s writings you’ll know that he has a penchant for long formal arguments (check out his SEP entry on the problem of evil for a good example of this). It should come as no surprise then to learn that his basic argument for active voluntary euthanasia is quite long. One of the nice features of this approach is that it tends to make for a logically strong argument. Tooley tends to build his case in a series a fairly uncontroversial stages, and these stages tend not to rely on implicit premises — as is often the case in arguments of this sort. That’s not to say there’s no controversy to be had — of course there is — but at least he tries to build a comprehensive case.

In the euthanasia essay, Tooley presents his argument initially as one whole unit and then works through the justification of the various stages. I’m going to reverse that order of presentation here: I’m going to go through the various stages first and then I’m going to present the whole argument, with an argument map, at the end. Here we go.


3. Stage One: Suicide can sometimes be in a person’s interest
The first stage of argument proposes that a person’s committing suicide is — under certain circumstances — in that person’s interest. It looks like this:

• (1) If a person is suffering considerable pain due to an incurable illness, then in some cases that person’s death is in his or her own interest.

• (2) If a person’s death is in his or her own interest, then committing suicide is also in that person’s own interest.

• (3) Therefore, if a person is suffering considerable pain due to an incurable illness, then committing suicide is in that person’s own interest.

This argument is logically valid (“If A then B” + “If B then C” → “If A then C”). It is also relatively innocuous: It says nothing, yet, about whether suicide is morally permissible. It only says that it can be in a person’s interest. Still, some people might object to its premises and we must see what can be said in their favour.

As regards premise (1), Tooley makes two supporting observations. First, he notes that many people who suffer from painful and incurable diseases come to welcome their own deaths. Since people are generally assumed to be good judges of what is in their interest, this implies that their deaths are (likely) in their own interests. Second, he notes that the family members of those who suffer from such diseases also welcome their deaths. We will add these two supporting observations into the completed argument map as (1.1) and (1.2) respectively.

As regards premise (2), Tooley notes that some religious believers are likely to reject this premise. For instance, Catholics who believe that suicide is a sin, and that anyone who commits it is destined for Hell, are likely to reject it. We’ll give this objection the number (2.1) There are a couple of ways to respond to this. One would involve a major detour into the philosophy of religion and might end up arguing that a good God is unlikely to send people to Hell for eternity. An alternative response — the one Tooley endorses in the interests of time — is to point out that Catholics think that many things (homosexual acts, premarital sex, contraception and masturbation) are sins. So anyone persuaded by Catholic doctrine on suicide must adopt a similar attitude towards these acts. The suggestion is that most people are unlikely to do this and so this objection to premise (2) fails. These points will be added to the argument map as (2.2) and (2.3).


4. Stage Two: Suicide is not (always) morally wrong
We now move on to the next stage of the argument. This stage focuses on the transition from “in a person’s interest” to “not morally wrong”. As follows (note: (3) serves as the first premise of this argument, but I’m not going to write it out again):

• (4) A person’s committing suicide in such circumstances may very well also satisfy the following two conditions: (a) it neither violates anyone else’s rights, nor wrongs anyone; and (b) it does not make the world a worse off place.

• (5) An action that satisfies conditions (a) and (b), and that (c) is not contrary to one’s own interest, cannot be morally wrong.

• (6) Therefore, a person’s committing suicide when that act does not violate conditions (a), (b) and (c) is not morally wrong.

There are a couple of things going on here. On the one hand, premise (5) is setting down certain conditions for moral rightness. On the other hand, premises (4) and (3) are saying that those conditions are met in certain cases of suicide. Let’s look at the conditions first and then consider whether they actually are met in certain cases of suicide.

Conditions (a) and (c) appeal to the idea that to be morally wrong an act must wrong some sentient being by violating their rights or undermining their interests (on certain conceptions of rights these are one and the same thing). By themselves these conditions would seem uncontroversial. The major objection to them is that they do not exhaust the conditions of moral wrongness. Derek Parfit, for instance, has a famous thought experiment in which you are asked to choose between two actions. The first of which will lead to future generations enjoying an extremely high quality of life, and the second of which will lead to future generations having lives that are not worth living.

The typical reaction to this thought experiment is that to perform the second action would be to do something morally wrong. But this reaction is difficult to explain if (a) and (c) exhaust the conditions of moral wrongness. After all, the future generations who are harmed by the second action are not yet alive and so cannot be wronged by your actions in the present. This suggests that there is more to wrongness than just harming the rights and interests of sentient beings (other thought experiments can be used to reach similar conclusions). And this possibility is exactly what condition (b) is designed to cover.

So the conditions of moral wrongness seem to be sound, now we must ask whether they will be met in certain cases of suicide. We have already seen in stage one how condition (c) can be met when the person is enduring considerable pain due to an incurable illness. So we focus here on (a) and (b).

Tooley argues that in the same circumstances condition (a) can be met. How so? Well, although it is true that those contemplating suicide in such cases will have obligations to others, they are unlikely to be able to meet those obligations due to the pain they are suffering (4.1). Furthermore, obligations usually allow for some level of cost-benefit analysis to determine whether they need to be fulfilled — if the personal cost of fulfilling the obligation is exceptionally high, as it might be in cases of incurable illness, then the obligations may be relaxed (4.2).

There is an obvious objection to this. Some might argue — contra the above — that ending one’s own life violates God’s right of ownership over us (4.3). Tooley detects three flaws with this response. First, it assumes that God exists when this is unlikely to be the case (4.4). Second, and more importantly, even if there is a God such a right of ownership is highly implausible since it conflicts with moral autonomy, which is generally thought to be a great good (4.5). Third, even if there is some right of ownership over non-autonomous beings — as there might be in the case of pets and their owners — this does not give the owner the right to compel the being to suffer needlessly (4.6). Tooley’s approach here is a bit too kitchen-sinky for my taste. I tend to think that in ethical debates of this sort one should either grant the most complex premises (like the existence of God) for the sake of argument, or else one should engage with them more fully. I don’t like the “this is unlikely” approach taken in (4.4).

Anyway, turning to condition (b), Tooley again thinks it highly likely that this condition will be met in the case of incurable illness with considerable pain. He does so on the grounds that death in these cases (i) ends the suffering to the individual, (ii) is likely to ease the emotional suffering of the friends and families of the individual, and (iii) is unlikely to generate any outweighing suffering due to loss of a loved one (4.7).

In sum, stage two of the argument seems well-supported.


5. Stage Three: Assisting Suicide is not morally wrong
Stage three of the argument makes the all-important leap from cases in which the individual takes their own life (suicide) to cases in which another person assists the individual in the taking of their own life. It says (again, (6) is an unwritten premise here):

• (7) It would be morally wrong for a person (call them “A”) to assist another in committing suicide (call them “B”) if and only if: (i) it was morally wrong for B to commit suicide; or (ii) committing suicide was contrary to A’s own interests; or (iii) A’s assisting B to commit suicide violated an obligation that A owed to a third party C.

• (8) Circumstances may well be such that A’s assisting B to commit suicide was neither (i) morally wrong for B; or (ii) contrary to A’s interests; or (iii) in violation of A’s obligations to any third party C.

• (9) Therefore, it may not be morally wrong to assist another in committing suicide.

This stage of the argument follows a similar pattern to the previous one. It sets some conditions for morally wrongful assistance and then it says those conditions are met in certain cases of assisted suicide.

Let’s look to the conditions of morally wrongful assistance first. Here, I must admit, I’ve hit upon a snag. Although conditions (i) and (iii) seem relatively straightforward, condition (ii) seems less so. The problem has to do with the ambiguity of Tooley’s original formulation of premise (7). Whereas I try to make it clear who is being referred to by introducing the characters A and B, Tooley does not and refers simply to “the person”. Unfortunately, this makes it unclear whose interests are being referred to in condition (ii). I’ve interpreted it above as referring A’s interests ( i.e. the interests of the assister) and I think this makes sense: it would seem imprudent (and likely a condition of wrongness) for A to assist another in undermining his interests. That said, it could be that Tooley is referring to B’s interests and drawing a distinction between objective and subject interests. In other words, the idea is that while B might subjectively think that a particular action (in this case suicide) is in their interests, they might be wrong about this when their interests are assessed from the third-person perspective. So if you, as an outside observer, think that the action is not in B’s interests, you should not assist them in performing it. Again, this seems plausible, but it also expresses a thought more complex than Tooley’s original formulation allowed for.

However the ambiguity gets sorted out, it seems like premise (8) will hold. We have already seen how suicide is not necessarily morally wrong for the person committing it, hence condition (i) can be avoided. Furthermore, there would seem to be circumstances in which either interpretation of (ii) fails to hold. Tooley acknowledges that some people may be members of organisations (religious or professional) which impose an obligation on them not to assist in the suicide of another (8.1). For those people, condition (iii) will be met. But Tooley responds by noting that this obligation will not, in general, be present and so, once again, there are circumstances in which (iii) will not be met (8.2).


6. Stage Four: From Assisted Suicide to Voluntary Active Euthanasia
The last stage of the argument is the easiest. It simply suggests that if assisted suicide is morally permissible, then so too is voluntary active euthanasia. The only difference between the two is that, in the former, the individual plays an active role in bringing about their own demise, whereas, in the latter, a third party does all the work. Tooley contends that this difference cannot be morally significant. So we get:

• (10) Wherever assisting a person in committing suicide is permissible, voluntary active euthanasia is also justified, provided the latter does not violate any obligation that one has to anyone else.

• (11) Therefore, voluntary active euthanasia can, in certain circumstances, be morally permissible.

The completed argument map is below.

Okay, that’s all for this post. In the next part, we’ll consider the distinction between passive and active voluntary euthanasia, and we’ll also look at the legalisation of euthanasia.

The Virtues of False Belief - A Puzzle

Stephen Stich

Sorry, it's been a slow week on the blogging front, and this is likely to continue on into next week. Here's something to tide you over until I get back to more frequent posting. It's essentially a paradox -- or, at least, I think it might be a paradox -- and I'd like your thoughts on it.

What I want to do is to look at a passage from Stephen Stich on the virtues of false beliefs. It's actually taken from an article by Michael Bishop and J.D. Trout on their epistemological theory Strategic Reliabilism (SR). The passage contains the paradox, but some background might be appropriate before quoting it, so here are the essentials: SR recommends that we adopt belief-forming strategies that are robustly reliable and efficient. In defending this, Bishop and Trout appeal to the Aristotelian principle that, in the long run, good reasoning tends to produce good outcome. Stich criticises this appeal because it reduces SR to a crude form of pragmatism. In other words, it would allow us to pick epistemic strategies that produce false beliefs simply because those beliefs will lead to better outcomes.

Here's what Stich says on this point (from p. 1059 of Bishop and Trout):

[I]n some very significant situations, having false beliefs leads to better outcomes than having true beliefs. Though examples are legion, perhaps the best known comes from the work of Shelley Taylor and her colleagues who have shown that 'positive illusions' and 'unrealistic optimism' in patients with HIV leads to both better psychological coping and slower progression of the infection. To put the matter simply, if you have false beliefs you live longer and have a higher quality of life.

Now I don't know much about Shelley Taylor and her work on HIV patients, but something about this passage struck me as being odd. If optimistic beliefs about one's future disease progression lead to better outcomes, then in what sense are those beliefs false? Surely, those who were optimistic were right to be so since they did, as a matter of fact, live longer and have a better quality of life?

On the face of it, Stich's claims about false beliefs seem paradoxical. At least, they seem that way to me. But I wonder if more could be said. The way I see it there are two interpretations of "false belief" at work here, and each can be used to support a different conclusion. As follows:

• (1) A belief about one's future disease progression is false if it is based on a faulty inference from existing evidence concerning patients with the same disease.
• (2) The patients in Taylor's HIV study drew faulty inferences from existing evidence about patients with the same disease.
• (3) Therefore the patients in Taylor's HIV study had false beliefs.

Or:

• (1*) A belief about one's future disease progression is false if, as a matter of fact, it does not correspond with the actual progression of one's disease.
• (2*) The optimistic beliefs of the patients in Taylor's HIV study did correspond with the actual progression of their disease.
• (3*) Therefore, the patients in Taylor's HIV did not have false beliefs. 

One problem with the second argument is that I don't know if (2*) is true because I don't know the content of their beliefs. It may be that their beliefs were completely out of line with reality but that they still did better than those with more pessimistic beliefs.

Anyway, here are my questions to you: Is there something paradoxical about Stich's false belief example? Does it simply highlight the difference between different epistemological theories? Or am I just being incredibly naive about the whole thing? Answers on a postcard (or in the comments section)

Game Theory (Part 7) - Functions, Limits and Derivatives

This post is part of my course on game theory. For an index see here. The course follows the one by Ben Polak on the Open Yale website.

Over the last few posts we’ve been working our way through the concept of best response. We’ve now reached an impasse: to take our analysis to the next level we’ll need to know how to find the maximum value of a function. This requires some elementary calculus. Some readers might be fluent in this area of mathematics. If so, they can skip the next few parts (there will probably be three of them). For those who aren’t au fait with calculus, I’m going to quickly run through the basics and provide links to some other resources.

Listen, I’m not particularly comfortable with calculus myself, and I certainly wouldn’t offer myself up as an internet oracle on this topic. But the level of calculus required for the types of game theory problem covered in this course is pretty low. If I can understand it, anyone can.

(Oh and incidentally, if there are any calculus gurus reading this, they might be kind enough to let me know if I make a mistake.)


1. What is a function?
Since our goal is to learn how to find the maximum value of a function, we must first ask: what is a function? This needn’t detain us too long. A function is simply a mathematical way of depicting the relationship between two variables: an independent variable (usually denoted by an “x”) and a dependent variable (usually denoted by a “y” or “f(x)”).

As the value of the independent variable changes, so too does the value of the dependent variable. In other words, every value of x is associated with one value of y. The domain of a function is the set of all x where the function can be meaningfully applied. The range of a function is the set of y or f(x) values that result.

Here’s an example:




According to this function, as the value of x increases (or decreases) the value of y increases in such a way that it is equal to the square of the x value. This function can be depicted graphically as follows.

Here’s another function:



According to this function, every unit increase in x leads to ten unit increase in y. This can be depicted graphically as follows:

2. What is a Limit?
So much for functions, now we move on to limits. Here’s a classic example of a limit in action:

Achilles wants to cross the road. The road is 10m wide. Before he does so, a rather annoying tortoise waddles up beside him and tells him its impossible to cross the road. The tortoise reasons as follows: in order to cross a road which is 10m in width, Achilles will first have to cross half that distance (5m); and in order to cross the remaining distance of 5m, Achilles will first have to cross half that distance (2.5m); and of course in order to cross the remaining 2.5m after that, he’ll first have to cross 1.25m; and so on ad infinitum. Since there are infinite number of half distances to cross, and since it is impossible to cross an infinite space, Achilles will never be able to cross the road.

What we have here is a limit. There is an infinite series (5 + 2.5 + 1.25.....) which has a limiting value of 10. By repeatedly crossing half distances, Achilles gets closer and closer to the full 10m distance, but never quite reaches it.

Although a little weird, limits are mathematically tractable. Indeed, when calculating the derivative of a function -- something that must be done when finding its maximum value -- one is finding a limit of a certain sort.


3. What is a Derivative?
Finally, we have the concept of a derivative. Put simply, a derivative is the rate of change of a function. More properly, it’s the rate at which the dependent variable changes with respect to the rate at which the independent variable changes. It’s easiest to understand this with an example in mind. And an easy example to work with is the y = 10x one from above.

Imagine this function depicts a runner (like Achilles) running along a road. The independent variable here is time and it is represented on the x-axis; the dependent variable is distance travelled and it is represented on the y-axis. Now let’s ask the question: what is the rate of change of y with respect to x? The answer, obviously, is 10: there are ten unit changes in y with respect. This is the derivate of this particular function.

That was pretty easy. An even easier example would be where the function depicts a runner who is standing still 10 meters from the start line. In this case y = 10 at all times. And so the dependent variable does not change at all with respect to the independent variable. Consequently, the derivative of this function is zero. There is a generalisable lesson from this as well: the derivate of any constant is always equal to zero.

A far more interesting derivative is that which can be calculate the accelerating force of gravity. This is discussed at length in the second episode of the 1980s TV series The Mechanical Universe . You can find it here.

Okay, that’s it for now. In the next part, we’ll go through the basic method for calculating a derivative in more detail.


Resources
In terms of books, I would recommend Calculus Made Easy by Silvanus Thompson. This is a classic text that was updated a few years back by Martin Gardner. It focuses heavily on facilitating comprehension of calculus, i.e explaining the rationale behind the various calculations. Most of the examples used in this post were taken from this book. I’d also recommend the Schaum’s Outlines books dealing with calculus. They focus more on practical applications and problem-solving.

In terms of videos, Salman Khan has quite a number of tutorials on calculus over at the Khan Academy website. I also found the youtube series by the Calculus Tutor to be helpful.

Mind-Body Physicalism (Part Four): Absent and Inverted Qualia

(Part One, Part Two, Part Three)

Right now I am looking at my laptop. To me it appears to be grey and black. Or at least, “grey” and “black” are the names I’ve come to associate with the colour experiences that I have when I look at it. Convention being what it is, you would probably associate the same names with your colour experiences of my laptop, but would our colour experiences really be the same? How do I know that your “black”-experience is not similar to my “green”-experiences?

These questions point us toward the problem of absent or inverted qualia. This problem forms the basis of an objection to mind-body physicalism that will be front and centre in today’s post. The post is part of a series on mind-body physicalism. And the series follows the material in William Jaworski’s Philosophy of Mind: a Comprehensive Introduction .


1. The Argument from Absent or Inverted Qualia
In the previous post, we discussed Frank Jackson’s famous knowledge argument against physicalism. This argument appealed to the private facts of experience (qualia), and their apparent separation from the subject matter of the physical sciences, in an effort to undermine physicalism. The argument from absent or inverted qualia does something similar. The argument itself looks like this:

• (1) If absent or inverted qualia are possible, then physicalism is false.

• (2) Absent or inverted qualia are possible.

• (3) Therefore, physicalism is false.

On the face of it, this is very simple stuff. But, of course, the devil is in the detail. We need to know exactly what absent or inverted qualia are and why they imply that physicalism is false; and we also need to know why absent or inverted qualia are possible. Let’s look at each of these issues in turn.

Inverted qualia are easily explained since they were alluded to in the intro. Qualia can be said to be inverted if different people have different qualitative experiences associated with the sensation of the same objects or states of affairs. As in your “black”-experience is equivalent to my “green”-experience. Absent qualia are slightly different. They can be explained by reference to the (infamous) philosophical concept of zombies. These are beings who are externally identical to us - i.e. they walk the same walk, and talk the same talk - but who completely lack the qualitative experiences we associate with activities such as walking and talking (note: there’s nothing special about these activities; I chose them for illustrative purposes only).

Why would either of these phenomena pose of problem for physicalism? Well, if physicalism is true, then qualia would have to be either (i) physical states of some sort or (ii) non-existent. Since we all appear (from our own perspective) to be having qualitative experiences, (ii) would seem like a non-starter. So qualia must be physical states. But if they are physical states, then their presence should be determinable by identifying physical states such as patterns of brain activation. This is where absent or inverted qualia become important. If such things are possible, then the same physical states can either (a) be associated with different qualitative experiences or (b) be associated with no qualitative experiences at all. But this can’t be right if qualia are identical to physical states. So the possibility of inverted or absent qualia would indeed imply the falsity of physicalism. Let’s phrase this in the form of an argument:

• (4) If physicalism is true, then qualitative states (qualia) must identical to specific physical states.

• (5) If absent or inverted qualia are possible, then the same physical state can be associated with completely different qualitative states.

• (3) Therefore, if absent or inverted qualia are possible, physicalism is false.

Finally, let’s move on to consider why absent or inverted qualia are possible. Again, if you’ve been following this series closely, it should come as no surprise to learn that a conceivability-possibility principle is doing all the work here. Proponents of the argument will say that since zombies and inverted qualia are conceivable (you just conceived of them as you were reading this, right?), they are also metaphysically possible. Hence, premise (2) of the argument is justified.


2. Responding to the Argument
In Chapter 4, Jaworski doesn’t go into the various responses to this argument in any great depth. This is mainly because he addresses them elsewhere in the book. His discussion of this argument is among the first stops on a very long trek through all the different physicalist theories. Still, a few words can be said about possible responses.

First, the argument relies on the dubious conceivability-possibility principle. We discussed the problems with this when looking at substance dualism. I advise the interested reader to read back over that discussion. In any event, even if the principle is sound, it is open to the physicalist to object to the true conceivability of absent or inverted qualia. They could say that the relevantly similar physical states must, necessarily, be associated with the same qualitative states. In doing so, they can challenge the proponent of the argument to come up with a clear and distinct conception of both phenomena.

Second, physicalists can reject the reality of qualia. As counterintuitive as it seems, several have taken this route. Daniel Dennett is probably the most well-known exponent of this view, but Wittgenstein’s private language argument has similar implications. Jaworski discusses both in chapter 8. To make this series somewhat self-contained, I’ll present Dennett’s argument now (I won’t evaluate it though).

Qualia are typically defined as properties that are (a) intrinsic/non-relational and (b) directly knowable. They are non-relational in that they do not play a part in the kinds of causal relations analysed by physicalists; and they are directly knowable in the sense that they are known non-inferentially from the first-person perspective. Dennett denies that qualia can be both of these things at the same time. His argument starts by assuming that proponents of qualia think that qualia play some role in our behaviour and then deduces from this the fact that qualia cannot exist. It looks like this:

• (6) Exponents of qualia must claim either (i) that qualia influence behaviour in conjunction with our beliefs, desires and other propositional attitudes; or (ii) that qualia influence behaviour independently of propositional attitudes.

• (7) If qualia affect behaviour independently of our propositional attitudes, then qualia cannot be non-relational.

• (8) If qualia affect our behaviour in conjunction with our propositional attitudes, then qualia cannot be directly knowable.

• (9) Therefore, qualia cannot be both non-relational and only directly knowable.

Premise (6) might seem a little odd, but it makes sense. Speech acts such as verbal reports are a kind of behaviour. So if speech acts like “I see a blue ball” or “I see a red ball” are linked with qualitative experiences — as proponents of qualia would have us believe — then those experiences must exert some influence on our behaviour.

Premise (7) is supported by the idea that if qualia directly influence behaviour, then they must do so by playing a direct causal role in behaviour, i.e. < Red quale → “I see red” >. So they would have to be defined in relational, as opposed to non-relational terms.

Premise (8) is a little trickier. The idea is that if qualia only influence behaviour when they are conjoined to other beliefs and desires, then one cannot know one’s qualia without knowing those other beliefs and desires. In other words, qualia can only be known when the surrounding circumstances are known. Dennett supports this idea with a few thought experiments. Here’s one:

• (10) Mad Scientist : A mad scientist has manipulated your brain while you were asleep. When you wake up, you declare that your sensory experiences are qualitatively different from the way they were before. But how can you know this? It could be that the mad scientist succeeded in altering your qualitative experiences, or it could be that he altered your memories. Either is possible if it is “qualia + beliefs” that influence behaviour. One can only tell the difference by knowing something about one’s memories and/or the brain states manipulated by the mad scientist.

This probably seems a little strange. It does to me, at any rate. But Dennett argue that denying the existence of qualia need not be as counterintuitive as it first appears. He reckons that a third-person conception of mental phenomena can accommodate most of the facts cited in support of qualia. He does so partly on the grounds that many phenomena that are thought to be non-relational turn out, on closer inspection, to be relational.

Like I said, I won’t evaluate this here but one obvious objection should be noted. The first premise of Dennett’s argument (premise 6 above) assumes that qualia influence behaviour. There is at least one school of thought — epiphenomenalism — that would deny this.

Okay, well that’s it for this series. As I said at the outset, unlike Jaworski’s book, this has been far from a comprehensive assessment of the arguments for and against physicalism. It was only intended to introduce some of the evidence cited in support of physicalism (argument from past explanatory success) and some of the classic objections to the physicalist worldview (Hempel’s dilemma, The Knowledge Argument, and the problem of absent or inverted qualia).

Mind-Body Physicalism (Part Three): The Knowledge Argument

(Part One, Part Two)

The travails of Mary, the brilliant vision scientist confined to work in a black and white lab, have been a staple in the philosophy of mind ever since they were first-described in a thought experiment by Frank Jackson. They’ll be featuring heavily in today’s post as well, which is part of my ongoing series on mind-body physicalism. As noted in previous entries, the series follows the discussion in William Jaworski’s Philosophy of Mind: a Comprehensive Introduction .

Jackson’s thought experiment is used to set-up something called the knowledge argument. The purpose of this argument is to illustrate the explanatory incompleteness of physicalism. If the argument is successful, there are grounds for dismissing physicalism; if it is not, then physicalism can live to fight another day. Thus, the defender of physicalism would be wise to address the argument.

In this post, we'll discuss the thought experiment, the argument, and the various responses. And we'll do so in that order.


1. What Mary doesn’t Know
Let’s get better acquainted with our fictional Mary first. She’s a brilliant vision scientist. If you have any questions about the nature of human vision, you should talk to her. She knows every physical thing there is to know about human vision: she knows about the anatomy of the brain; she knows about the electrical and chemical responses associated with vision; she knows about the electromagnetic properties of different objects; and she knows which electromagnetic properties are associated with which physiological responses in the brain.

But here’s the thing. For some reason, Mary has spent her whole life in a black-and-white environment. The walls of her lab are painted black; all her lab equipment is white; her clothes are black; she wears black and white gloves; and her skin is painted white. As a result, she’s never actually had the experience of colours such as red or yellow. So although she could tell you all about the electromagnetic properties of red objects, and the brain states associated with the sight of red objects, she hasn’t seen any red objects for herself.

Now suppose that one day she manages to break free from her black-and-white lab, and go on a trip to the local market. While there, one of the vendors tries to sell her a tomato. She looks at this strange object for the first time, contemplating what she sees.

Question: does Mary acquire any new knowledge by looking at the red object?

2. The Knowledge Argument
To most people, the answer to that question is “yes”. By seeing a red tomato for the first time, Mary learns that the colour red is associated with a unique qualitative experience, one that she has not had before. Thus, although she knows everything about the physical nature of vision, she knows something more now: she knows what it is like to experience the colour red.

This intuitively appealing answer creates a problem for the physicalist. The problem can be expressed in the form of the following argument:

• (1) If physicalism is true, then all facts are physical facts.
• (2) If it is possible for someone to know all the physical facts without knowing all the facts, then not all the facts are physical facts.
• (3) If it is conceivable that someone can know all the physical facts without knowing all the facts, then it is possible for someone to know all the physical facts without knowing all the facts.
• (4) It is conceivable that someone can know all the physical facts without knowing all the facts.
• (5) Therefore, it is possible for someone to know all the physical facts without knowing all the facts (from 3 and 4).
• (6) Therefore, not all the facts are physical facts (from 2 and 5).
• (7) Therefore, physicalism is false (from 1 and 6).

Let’s talk about the support for this argument first. Premise (1) seems to be an accurate statement of the physicalist thesis. Premise (2) depends on the following train of thought: if one knows all the physical facts but does not know all the facts, then there must be a fact (call it “q”) that one does not know. If q were a physical fact, then one would know it. So q must be a non-physical fact. But in that case it follows that if it is possible to know all the physical facts and not know q, then not all facts are physical facts. Phew! Read through that again if you need to.

Moving on, premise (3) incorporates a conceivability-possibility principle. This allows us to say that the conceivable is possible. We discussed such a principle before in relation to substance dualism. Now would be a good time to check back over that discussion. Finally, premise (4) is supported by the Mary thought experiment. The thought experiment has three key elements to it:

• (8) The Mary Thought Experiment The following scenario is conceivable: (i) Mary knows all the physical facts; (ii) Mary has never experienced colour; and (iii) Mary learns a new fact upon experiencing colour for the first time. Since no one can learn something that they already know, it would seem to follow that (4) is true.

3. Responding to the Argument
How then can the physicalist respond? Well, premises (1) and (2) would seem rather unobjectionable. Premise (3) is definitely objectionable, but the possible objections were already covered when looking at substance dualism. That leaves premise (8) (which supports (4)). Jaworski says that the physicalist can object to the conceivability of either one of the three elements of the thought experiment, or some conjunction of the three elements. Let’s look at how this might play out in practice.

One could argue that it is impossible to have complete knowledge of the physical facts (contrary to (i) above). This could be due to some inherent limitation of the human sciences. Thus, although science progresses in incremental steps, and improves with most of those steps, it never quite obtains perfect knowledge. Instead, the knowledge curve is asymptotic. This model of scientific knowledge is compatible with Popper’s fallibilism.

Alternatively, one could argue that the conjunction of (i) and (ii) is inconceivable. In other words, one could argue that someone cannot know certain physical facts unless one has had experiences of colour. I’m not exactly sure how that argument would run but it has some prima facie plausibility.

The conjunction of (i) and (iii) can be challenged in a variety of ways. Some critics challenge the idea that one learns a new physical fact when one has colour experiences. They say that, instead, one learns how to see the same set of physical facts under a different description or representation. To be precise, they say that one shifts to a first-person representation from a third-person one. So the facts remain the same, all that changes is how they are represented. That’s a little esoteric, so another way to challenge (i) and (iii) is to argue that physical facts logically entail facts about conscious experience. Thus, anyone who knew all the physical facts would be able to deduce facts about conscious experience. It’s been a long time since I read it, but I seem to recall Daniel Dennett offering this up as a possibility in Consciousness Explained (of course, he objects to the standard understanding of qualia as well).

There is a third way in which to challenge (i) and (iii). It is to adopt the ability hypothesis. According to this hypothesis, there is a distinction to be drawn between two types of knowing: (a) knowing-how and (b) knowing-that. The former involves knowledge of abilities and skills; the latter involves knowledge of facts. Applied here, the distinction allows us to say that when Mary experiences the colour red for the first time, she does not learn a new fact; instead, she learns a new skill.

Here’s a list of all these objections to premise (8):

• (9) It is inconceivable that anyone could have complete knowledge of all the physical facts.
• (10) It is inconceivable that one could know all the physical facts without having had conscious experiences of colour.
• (11) Mary does not learn any new facts when she has a conscious experience, instead she represents the same facts in a different way.
• (12) Anyone who knew all the physical facts would be able to deduce facts about conscious experience from them.
• (13) Mary does not learn a new fact when she has a conscious experience, instead she learns a new skill.

Do any of these responses work? Very hard to say. As Jaworski notes, both the knowledge argument and the responses to it remain highly controversial.

Mind-Body Physicalism (Part Two): Hempel's Dilemma

(Part one)

This post is the second in a brief series on the basic arguments for and against mind-body physicalism. The series follows the discussion in William Jaworski’s book Philosophy of Mind: a Comprehensive Introduction . This post is subject to all the caveats and qualifications mentioned in the first post.

To recap a little, the mind-body physicalist is, at the most abstract level, committed to the view that mental reality is ultimately identical to, supervenient upon, or realized by the entities posited in fundamental physics. As we saw the last day, one argument for this thesis is the argument from past explanatory success: physicalist explanations have been successful in the past so they are likely to be successful in the future. In today’s post we’re going to consider a classic objection to physicalism: Hempel’s dilemma. This is, in fact, a specific instance of a broader problem in the philosophy of science and so has ramifications that extend beyond the mind-body problem.

Let’s see what all the fuss is about.


1. Hempel’s Dilemma
For the purposes of this presentation, I am going to reach beyond the confines of Jaworski’s book and look instead to (part of) the discussion of Hempel’s dilemma in Andrew Melnyk’s book A Physicalist Manifesto . I do so because - solid and all as Jaworski’s presentation is - Melnyk is slightly clearer about both the constraints facing the physicalist that give rise to the dilemma, as well as the subsequent implications of the dilemma. Indeed, Melnyk has a gift for clarity, rigour (and, indeed, humility) that is on display throughout his book. This gift makes his probably the best overall defence of physicalism on the market.

Anyway, Melnyk notes at the outset of his book that a physicalist need not perform any sort of conceptual analysis on the term “physical”. This is because the physicalist’s goal is not necessarily to closely track ordinary language or meaning, but instead to provide content to a thesis. Thus, it is open to the physicalist to provide an entirely stipulative definition of the “physical” and work from there. Still, even that stipulative definition will be subject to some constraints. He lists three:

(i) It cannot be obviously false : This seems like a straightforward constraint. Anyone who commits themselves to a thesis cannot also be committed to its falsity, can they?

(ii) It cannot be analytic or trivial : This seems legitimate. For example, if physicalism were simply defined as the thesis that “whatever exists is physical” it would be trivially true. It would have no possibility of being false and would say nothing interesting about the fundamental nature of reality (including mental reality).

(iii) It must have some content that is determinable now by us: This, also, seems legitimate. We cannot, it would seem, accept a theory that is devoid of currently determinable content because such a theory would have two unwelcome implications. First, it would not automatically exclude many things that we now take to be non-physical. And second, it would prevent us from taking currently available scientific evidence as evidence for or against physicalism.

Although each of these constraints is plausible, they create a bit of a problem for the physicalist. The problem is that it is impossible for an adequate definition of physicalism to satisfy both (i) and (iii) at the same time. This can be expressed in the form of an argument, as follows:

• (1) If “physicalism” is to be an adequate theory, it’s definition must satisfy three conditions: (i) it must not be false; (ii) it must not be trivial and (iii) it must have content that is determinable now by us.

• (2) “Physicalism” can either be defined by reference to the current content of physical theories or to the content of some future ideal physical theory.

• (3) If “physicalism” is defined by reference to current physical theories, then conditions (ii) and (iii) are met but (i) is not.

• (4) If “physicalism” is defined by reference to a future ideal physics, then conditions (i) and (ii) are met but (iii) is not.

• (5) Therefore, physicalism is not an adequate theory.

Now you may be wondering: what reason do we have to accept (3) and (4)? The answer is the following. We have reason to accept (3) because past experience suggests that physical theories are constantly being refined, replaced and superseded by better physical theories. So if past experience is any guide - and who are we to assume otherwise? - the content of current physical theories is almost certainly false. We have reason to accept (4) on the grounds that a future ideal physics must, necessarily, have content that is not now determinable by us, otherwise we would already be in possession of the ideal theory.

The argument contains within in it a dilemma, usually attributed to Carl Hempel: either the physicalist accepts a theory that is almost certainly false; or he accepts a theory that has no content; he can’t do both.



2. Responding to the Dilemma
I’ll switch back to Jaworski’s book now. He notes that, as with all dilemmas of this sort, there are various strategies open to the physicalist in response. They can grasp one or other of the horns and say that the implications are not as dire as they first appear; or they can deny one of the premises that gives rise to the dilemma, thereby slipping between its horns. Jaworski notes that the second strategy is - perhaps surprisingly - not all that popular (although Melnyk could actually be interpreted as opting for that approach). Instead, most defenders of physicalism have grasped one of the horns.

For instance, there are those who say that accepting a theory, even though it is likely to be proved false in the future, is not that big a deal (again, Melnyk could be interpreted as taking this approach). They take their inspiration from the fact that this is simply par for the course in physics. One defends whatever theory seems most likely to be true at a particular moment in time. This is how we progress toward better theories. There’s no real problem here.

• (6) There is no real problem associated with accepting a theory that is probably false: this follows best scientific practice.

Alternatively, there are those who accept that physicalism must be defined relative to an ideal physics. They tend to deny that a commitment to physicalism in the here and now lacks content. They’ll say current physics provides some clue as to the content of future physics. They justify this claim by pointing out that although physical theories have been refined and replaced over the past 400 years or so, the older theories are rarely deemed to be completely false. Some of the content from those theories carries over. Thus, even if physics hasn’t bottomed-out at the fundamental level of reality yet, we know enough now to say that mental entities will not exist at that fundamental level. They will, instead, be made up of components from that level.

• (7) Defining physicalism relative to an ideal future theory does not render it devoid of content.

As I see it, both (6) and (7) function as denials of (1). That is, they supply reason for thinking that a theory which fails to meet those three conditions can still be adequate. This is reflected in the diagram below.

Okay that’s it for now. In the next post we’ll consider the famous knowledge argument against physicalism.

Mind-Body Physicalism (Part One): The Argument from Past Explanatory Success

Since I did a whole series on the basic arguments for and against substance dualism, I thought it might be nice to do a symmetrical series on the basic arguments for and against mind-body physicalism. I’m sure some of my readers will like this too - they suggested as much in the comments section. As with my series on substance dualism, William Jaworski’s book Philosophy of Mind: a Comprehensive Introduction will be the source material.

It’s only right that I warn you at the outset: Although the motivation for this series is to serve the interests of symmetry, there are differences between the treatment of the two positions that will make this series on physicalism far less satisfactory than the one on substance dualism. Primarily, this is due to the fact that there has been a lot more theoretical refinement of physicalism over recent years. Indeed, such is the volume of theoretical refinements that Jaworski spends four whole chapters going over them.

I don’t wish to follow each and every refinement here - there’s no sense in producing the book as a whole - so instead I’ll just cover one basic argument for physicalism (the argument from past scientific success) and three objections to physicalism (Hempel’s dilemma, the knowledge argument, and the problem of inverted qualia). These three objections provide the springboard for the further refinements mentioned above. Some of these are impressive and the arguments in their favour can be quite compelling, but if you’re interested in these then I recommend getting a hold of Jaworski’s book (this is the last recommendation for a while - I don’t want to end up as Jaworski’s personal promoter).


1. The Argument from Past Explanatory Success
Physicalists come in many flavours, but they usually share one basic commitment: the commitment to the fundamentality of the physical sciences. That is to say, they all tend to believe that whatever reality ultimately consists in will only be properly described using the language of physics. Furthermore, that which is properly described using the language of physics is called “physical”. So since the mind is part of reality, it would seem to follow that mind must ultimately be physical.

Clearly this commitment to physics is in want of justification. This is where the argument from past explanatory success comes into play. Before discussing that argument it’s worth making something clear: there are other arguments in favour of physicalism in general and also in favour of particular forms of physicalism. Indeed, we encountered one such argument - the argument from the problem of interaction - when looking at substance dualism. But even that argument would seem to trace its authority back to the explanatory success of physics. Anyway, the argument itself takes the following form:

• (1) If explanations of type A have, in the past, been superior to explanations of type B (with respect to a broad range of subject matters), then explanations of type A are likely to be superior to explanations of type B with respect to other subject matters.

• (2) Physical explanations have, in the past, been superior to non-physical explanations with respect to a broad range of subject matters.

• (3) Mind-body relations are a subject matter in want of an explanation.

• (4) Therefore, physical explanations are likely to be superior to non-physical explanations with respect to mind-body relations.

Now this might look a little bit strange. For one thing, it doesn’t appear in this form in Jaworski’s text. He presents the argument as a straightforward {“Physical explanations have been superior to non-physical explanations in the past” → “Therefore, physical explanations are likely to best with respect to mind-body relations”} inference. His version makes the inductive gap between the premise and the conclusion transparent. I’ve tried to plug this gap by introducing an explicit inductive principle in the shape of premise (1). But this does not change the overall strength of the argument.

And this is the critical point. Inductive arguments of this sort cannot provide decisive reasons in favour of a particular conclusion. They can only provide probabilistic reasons for supporting a conclusion. The probabilities in question might be very high, but they are probabilistic nonetheless. Does this make things easier for the critic of physicalism? Not necessarily. We each of us rely on inductive principles, so the proponent of an alternative theory should be reluctant to dismiss the argument solely because it is inductive in nature. Instead, they should prefer to provide some good reason for thinking induction is unwarranted in this particular instance. Which brings us to….


2. Supporting the Argument
The key to the argument from past explanatory success is the support given to premise (2). If many impressive examples of successful physical explanations can be given, then dualists will have their work cut out. To block the induction from these case studies, they will need to show that mind-body relations are completely disanalogous to them. That’s certainly not impossible but it must be done nonetheless.

So what examples can be adduced in support of premise (2)? Jaworski offers four. Now, I’m not a historian of science so I can’t really vouch for the accuracy of each of them. They sound plausible to me but, for instance, I have no idea if people ever really did explain magnetism by appeal to non-physical spirits. Also, I would presume that the success of physicalistic explanations in each of these domains is determined by following the rules of inference to best explanation or some probabilistic alternative (Bayesian or Likelihoodist). In other words, physicalist explanations win against competitor explanations because they are simpler, afford us greater predictive and manipulative powers, confer a higher probability on the data and so on ( see this series for more ).

Anyway, the four examples are:

• (2.1) Magnetism : At one point in time people tried to explain magnetic by positing the presence of nonphysical spirits in magnetised objects. A physicalistic explanation of magnetism in terms of the electromagnetic force proved far more successful.

• (2.2) Planetary Motion : At one point people thought non-physical intelligences (gods) could account for the orbital movements of the planets. This was replaced by a far more successful physicalistic explanation of those movements by reference (initially) to Newtonian laws of gravity and (eventually) to the warping of spacetime.

• (2.3) Life : People once thought that the only thing capable of explaining the nature and behaviour of living things was by positing the existence, in them, of non-physical vital spirits. This has now been replaced by a far more successful explanation of life in terms of mechanical metabolic and reproductive processes.

• (2.4) Mental Illness Abnormal human behaviour was once explained by reference to possession by non-physical beings. Now many (if not all) such abnormalities can be explained by reference to tissue pathologies or alterations in the electrical and chemical balance of the brain.

We can plug these four examples into the argument and then map it out as follows.

Now as has been stressed already this argument is far from watertight. We’ll consider the various problems with it, and with physicalism as a whole, over the remainder of this series.