Tuesday, September 25, 2012

Free will incompatible with determinism and indeterminism

To: Kathleen C.
From: Geoffrey Klempner
Subject: Free will incompatible with determinism and indeterminism
Date: 9th June 2008 13:49

Dear Kay,

Thank you for your email of 29 May, with your fourth essay for the Philosophy of Mind program, in response to the question, 'Summarise the argument that free will is impossible, whether on the assumption of determinism or on the assumption of indeterminism. Do you see any loopholes that the defender of free will might exploit?'

I can definitely detect the influence of our previous discussions of this problem. We are in agreement over the main points in the argument, as well as over the suggestion that somehow a Cartesian soul would possess the power to make decisions which were neither 'determined' nor 'not determined'.

Every time I look at this topic -- most often, when one of my students sends me an essay on it -- I find myself rehearsing in my own mind the argument from the dilemma, 'determined/ not determined', trying to see if I can somehow catch myself off guard and think of an alternative which I haven't though of before.

We are not told how the soul is different from any other entity with a 'nature' (physical or non-physical). A physical nature involves processes which take place in 'matter', chemical or electrochemical or whatever. A non-physical nature would involve -- what exactly? Explanation in terms of beliefs, desires and intentions, in other words the terms of folk psychology, may imply causation but as Donald Davidson argues there are no 'laws' of the mental realm comparable to the laws of the physical realm. This is what he terms the 'anomalousness of the mental' (see Davidson's paper 'Mental Events').

The famous example (I can't remember whether I have given this before) is taking an orange from the fridge. An natural explanation would be that I wanted an orange (desire) and I believed that there was an orange in the fridge. However, as Davidson argues, the very same sequence of behavioural events *could* in principle have a different psychological explanation. Because of the 'holism of the mental' there is no way to identify beliefs and desires independently of assumptions about other beliefs and desires, and so on ad indefinitum.

Another, simpler, way of putting is would be to say that beliefs and desires are not 'things in themselves' but rather labels which we use to make sense of a person's behaviour. I'm not laying any heavy metaphysical weight on the notion of a 'thing in itself' here. A table or a chair are things in themselves. So is a brain or a neuron.

Davidson argues in 'Mental Events' that since there are strictly no 'laws' of psychology, the causation implied by such statements as, 'He took an orange from the fridge *because* he wanted one', requires laws at the physical level. That is his argument for the identity of mental and physical 'events'.

Denying mental monism, if Davidson's argument is sound, requires that we give up the idea of mental causation. But in favour of what? That was the question. I still don't have an answer to that, a plausible 'get out' for the Cartesian who wants to talk of psychological explanation without causation (whatever that would mean).

Sorry if this sounds a bit like talking aloud. I haven't come up with any new lead, though I hardly expected to ;-)

I've seen a book with the subtitle 'Varieties of Free Will Worth Wanting'. The idea being that given the argument from dilemma, it looks increasingly likely that we don't have a coherent idea of what we want a 'free will' to be. That's how bad it is. It's not as if we could imagine or conceive what 'having a free will' would be like but, 'Sorry, you can't have one.' Rather, we don't even have a coherent idea of what it is that we 'want'. Hence the idea of searching around for something 'worth wanting'.

'I don't know what is worth wanting. I only know that I *am* free,' would be the unphilosophical response. My best shot at this is that has something to do with the clash between the subjective and objective viewpoints -- a point in which I am agreement with Thomas Nagel.

Where I disagree with Nagel is over the metaphysical significance of what Nagel terms the necessary 'penumbra of ignorance' of an agent of the causes of his actions. The way Nagel puts this implies that 'possession' of free will is, ultimately, a matter of ignorance. Whereas, I would want to say that (somehow) the subjective standpoint comes *before* the objective, not after it, and therefore that our freedom as agents is more real than anything else in the 'known' universe.

All the best,


Perception and the limits of human knowledge

To: Diane F.
From: Geoffrey Klempner
Subject: Perception and the limits of human knowledge
Date: 6th June 2008 12:55

Dear Diane,

Thank you for your email of 26 May, with your fourth essay for Possible World Machine, in response to the question, 'What is perception? Explain the role of perception in an account of the nature and limits of human knowledge.'

I did not know that 'cats do not go around'. That's very interesting! I want to start with this because it shows something about the nature of perception which tends to get left out when we concentrate on 'perceiving a table' or 'perceiving a tomato'.

Cats are great at jumping and scampering up steep inclines so it is hardly surprising if a cat's first instinct is to climb over rather than go around. However, human beings faced with a similar choice do not depend on instinct but rather on our *perception* of the obstacle, in its context.

Just as you can perceive an object, conceived as an obstacle, so you can also 'perceive' a possible route past the obstacle. A car driver sees 'room to squeeze through' and makes for the gap in the traffic.

Scepticism about perception seems absurd, or pointless, when seen in this practical context. Could one go further and state that the very nature of the 'things' which we perceive is defined by our practical interests? That's a point that one of the speakers makes in the unit on perception.

Seeing something *as* a possibility of going through, or over, or round is just one dimension, where we are concerned with the action of getting from A to B. But there are many other kinds of action which involve other kinds of corresponding perception. Say that I am a bit overweight, and I cast a glance at the collapsible chair offered by my host, trying to gauge whether it will bear my weight. Or, I gently pick up the tiny glass figurine from the mantelpiece, because I see it *as* fragile.

What this more generalized notion of perception implies is a capacity for judgement which is in a sense unmediated by calculation or reasoning. I can see just by looking at your face that you are worried (perception) or I can work it out from various bits of evidence that I have pieced together, such as actions you have done or emails you have sent. The end judgement -- the fact that you are worried -- is exactly the same in both cases but the route taken to get there is very different. This shows something essential about the concept of 'perception'. To say that perception is essential to human knowledge is to assert, as a necessary or a priori truth, that *not* all knowledge can be acquired by 'calculation or reasoning'.

Understanding another person's words is another important example of perception. There is all the difference in the world between hearing someone 'say' something, and struggling to translate someone's words using a dictionary or phrase book.

The question is about the 'nature and limits of human knowledge'. Why is perception needed for knowledge? Could there be beings who didn't need powers of perception? 'Only if they already had all the knowledge that they would ever need.' However, that seemingly obvious response doesn't answer the question. Computers don't perceive, but they do have informational inputs (CD drives, keyboards etc.). Each of us has lots of knowledge which can be expressed verbally -- in a way that could be uploaded into a computer -- but there has to be some other way of acquiring knowledge, which is prior to verbal expression, otherwise there would be nothing for the words to be 'about'.

You give the well known example of wondering whether the colour we call 'blue' is the same for both of us. A blind person knows what 'the sky' is, in a sense, they can talk intelligently about the sky (as something aeroplanes fly across, has occasional clouds, as a place where you could keep going 'up' forever and so on) so what exactly is lacking in their knowledge? What does a knowledgeable blind person *not* know about the sky?

Let's start taking away the senses. Sight, sound, smell. Touch? could you take away that too? Helen Keller was deaf and blind, but her teacher still had the rich resources of feeling and touch to call upon. You can see where this is going. Imagine a human being with even more impoverished senses, who is only capable of feeling one thing, a sharp pin prick, or a whiff of onion. Would you try to tap out a Morse code of pin pricks or onion whiffs? How could they possibly learn how to decipher the code?

And yet, someone whose senses had decayed over time might reach precisely this state, not losing their knowledge, still able to communicate.

These questions are very difficult. Of course, one can discuss all the usual things about perception such as arguments for or against idealism, qualia and so on. But, to me, the issue of the 'nature and limits' of human knowledge is looking for something more fundamental, something which in a sense we need to tackle first, before we get into all these fangled philosophical issues.

All the best,


Determinism vs fatalism, and truths about the past

To: Jeffrey D.
From: Geoffrey Klempner
Subject: Determinism and fatalism compared
Date: 6th June 2008 12:07

Dear Jeffrey,

Thank you for your email of 25 May with your third essay for Possible World Machine, entitled, 'The maximum likelihood of fatal determinism,' in response to the question, 'Compare the theory of fatalism with the thesis of determinism. Is there any way that one could consistently hold a determinist view while denying fatalism, or hold a fatalist view while denying determinism?', and your email of 1 June, with your notes on unit 8.

Fatalism and determinism

I remember seeing a film 'Outback' where a young schoolteacher on his way to visit his girlfriend breaks down in the outback and loses all his money (as you do) in a game of two-up in the local bar. To cut a long story short, his life goes downhill from that point and he ends up miraculously surviving a suicide attempt.

Undoubtedly, a fatalist or a determinist in this situation would have a particular kind of *attitude* to what is happening to them, but it is not so clear that any practical course of action follows if you are for, or against, fatalism or determinism. It could be argued that as a fatalist (or a determinist) he might be more philosophical about his circumstances, and this has practical benefits. But the options facing him are the same irrespective of his philosophical view.

In your account of the different attitudes towards playing two-up, I could readily understand the debate between the classic equiprobabilist who holds that each throw is independent, and the Bayesian who takes the more pragmatic attitude that one should allow previous results to influence the probability assignment. In favour of the Bayesian approach, it could be said that we don't *know* that the coins are fair. If they are not, then the Bayes approach has a better chance of success.

(Of course, the organizers of the two-up event might know that the teacher is a Bayesian and deliberately manipulate the results so that a Bayesian is more likely to lose.)

What has this got to do with fatalism and/ or determinism? Not much, really. The choices for the gambler are very limited: bet on two heads, two tails or a head and a tails. It doesn't take a mathematical genius to calculate the odds. I don't think that a determinist would, as you suggest, try to predict the outcome on the basis of prior conditions because there are too many variables. If you tried to make a machine which tossed two heads every time, you would need to have incredibly precise control which I don't think is practically achievable. The point here is the same one as Lorenz made about the butterfly flapping its wings in Japan.

However, as I indicated above, if you are a fatalist you might be more philosophical about the outcome, less anxious as the coins fly through the air, resigned when you lose and so on.

What is the difference between determinism and fatalism?

Briefly: fatalism, as the philosophical view that statements about the future 'already have' a truth value, or are 'true now or false now', can hold even in a universe where determinism doesn't hold. On the other hand, you can be a determinist who rejects the idea of there being 'future truths' or 'future facts' in the sense held by the fatalist. Either way, the future is 'closed' rather than 'open', but for the determinist it isn't quite so closed as for the fatalist, because there is always the logical possibility that the laws of nature might change, or that determinism, which has been true at every time up to the present, might, at some time in the future, cease to be true.

You talk about assigning a probability of I. There is a sense in which, for the fatalist or the determinist, the 'objective' probability of any event is 1 or 0. However, such notion of probability isn't really much use. The point of probability judgements is that they are a guide to action. In order to assign a probability of 1 you have to be absolutely certain that a particular event will occur. If you are not certain, then the probability (from your perspective) is less than 1, regardless of whether or not you are a fatalist and/ or determinist.

Unit 8

It is agreed by all sides that to believe that P is to believe that P is true, or that it is true that P. This is what you would define as a 'relative truth' in the sense that it doesn't follow from the fact that I believe that P is true, that P *is* true, because my belief can be true *or* false. It is true for me, but only so long as I do not encounter any evidence that tells against my belief.

One could go on to describe the 'world' of my belief system, which corresponds at various points to the actual world (where my beliefs are true) and fails to correspond at other points. The actual world is the world of 'absolute truth', because it doesn't depend on what people believe, or indeed whether there are people at all.

The question, however, is why we need the idea of an 'actual world', conceived of as something absolute and existing for all time as the 'final set of answers' to every question. As you say, every judgement is made against a background of what you term 'boundary conditions', agreed methods of investigation, theories, methods of proof and so on. Whereas the notion of an absolute truth, the final set of answers, doesn't depend on any 'conditions' but only on itself.

Once again, as with the question of fatalism/ determinism, we seem to have a debate which does not have any obvious practical consequences. What difference is it going to make to you, as an investigator of 'truths', whether you believe in the existence of the 'absolute set of truths' (which no-one can ever know). All you can ever know, is what you learn by pursuing the methods of investigation that are available to you.

This is the peculiar thing about philosophy, that it raises questions which seem very important yet do not have an obvious practical application. It seems important, somehow, that the truth is 'out there' irrespective of our beliefs or assumptions, yet it is hard to see what practical difference it makes to hold this belief.

It could be objected to what I have said here that there is a kind of 'relativism' about truth which very definitely does have practical consequences, and that is the idea that you can 'control' or 'create' the truth, as in the world of 1984 where old editions of newspapers are edited and rewritten. Or you could be the kind of 'relativist' who holds that in a debate over abortion or religion or cosmology both sides are right. The 'truth' is just what anyone happens to believe. In that case, we might as well give up on talking of truth. There is no point in every arguing about anything, because everyone is always right.

This kind of 'lazy' relativism comes a bit unstuck, however, when you consider practical things like 'how strong the girders need to be for this bridge'. However, I suppose that if the bridge collapses it is still open to the designer to insist that nothing of the sort has happened everything is just fine.

All the best,


Interactionist dualism versus epiphenomenalism

To: Kathleen C.
From: Geoffrey Klempner
Subject: Interactionist dualism versus epiphenomenalism
Date: 27th May 2008 11:43

Dear Kay,

Thank you for your email of 13 May, with your third essay for the Philosophy of Mind program, in response to the question, 'Contrast the main features of interactionist and epiphenomenalist versions of mind-body dualism.'

With my University of London external students safely through their exams, I allowed myself to be very lazy last week. I came back to my office this morning after the Bank Holiday with 126 emails to sort through!

The question refers to an 'epiphenomenalist version of dualism'. Confusingly, recent debate in the philosophy of mind has focused on arguments for and against epiphenomenalism within a broadly materialist/ physicalist view of the mind.

It seems obvious, as you argue, that if human beings are the products of evolution then the capacity for consciousness, viewed from a dualist standpoint as the capacity to emit or produce non-physical mental events would seem the purest case of evolutionary baroque, sheer accident so far as our physical capacities are concerned.

However the question is not quite so simple when one factors in debate over epiphenomenalism within a materialist view. It all depends on how one views the 'direction of explanation' in accounting for the way in which physical events in the brain cause, and are caused by external events in the world (in the former case bodily movements, in the latter case perceptions).

On a 'non-reductive' materialism, there is a genuine role for explanation in terms of beliefs, desires and intentions -- the terms of 'folk psychology' as philosophers call it -- which is in some sense prior to explanation on the purely neurological level. The question is, are the explanations we give in folk psychology real, or merely illusory? When I tell you that I converted the file you sent me for printing, in order to have a copy to read when I responded to your essay, is that the literal truth about the processes of cause and effect, or is the real story one about neurons firing? In the latter case, what we term 'belief' or 'desire' -- or 'consciousness', viewed from a materialist perspective -- are just epiphenomena relative to what is really going on underneath the bonnet, in the brain. As we give our explanations in folk psychology, we are under the illusion that we are offering genuine explanations, when in fact we are not.

The question of the role of consciousness in evolution now acquires a new twist. Human beings do need the capacity for consciousness in order to accomplish tasks which could not be accomplished without it. But even accepting this point still doesn't settle the question over the reducibility or non-reducibility of folk psychology. It all depends on how one explains 'consciousness' from a materialist point of view.

On the question of Cartesian mind-body interaction and speculation about quantum effects in the brain, the point here is that the conservation of energy is preserved provided that the overall rate of change (e.g. radioactive decay) is what would be predicted by our knowledge of physical laws. There was a series of experiments conducted at my old college, Birkbeck, a few years ago by an eminent physicist who got subjects to attempt to 'predict' when a click would sound on a Geiger counter. The idea being that, even if the overall number of clicks per hour or per minute is preserved, there might yet be a measurable correlation between predictions and clicks, implying some kind of 'interaction' between the subject's mind and the radioactive sample. (I heard this second-hand, but I understand that the experiments were inconclusive.)

Radioactivity is not the only example of a quantum phenomenon. Another is the humble neon light, which is actually the combined effect of billions of individual random flashes. Perhaps by thinking hard enough, you could cause your name to be spelled out on the neon light in your kitchen. Even if you only succeeded in causing a momentary flicker that would be an astounding result. (Of course, you could never know for sure -- but suppose you were able to repeat the experiment on demand.)

It is impossible to rule out, at the present state of scientific knowledge, that the changes which occur in the neurons of the brain are governed by a similar 'probabilistic' effect which is indeterminate at the quantum level, allowing for the possibility that the brain could function as a 'relay' mechanism between the physical body and a Cartesian soul substance. We don't even need to posit soul substance. Just call the mind a non-physical force and leave the question of its identity open.

I'm not sure you've grasped the point about criteria of identity. In the unit, there were two arguments given, one against the materialist and one against the dualist.

The point against the materialist who accepts the story about 'inner somethings' at face value but insists that they are 'identical' with events in the brain, is that there is no criterion for this identity statement. One-to-one correlation would be indistinguishable from identity. Nothing is gained by using the term 'identical'.

The point against the Cartesian dualist is that there is no criterion for the 'identity' of soul substance across time, or indeed for the number of soul substances associated with a given body. There could be a thousand 'souls of GK' thinking the thoughts that lead to these words being typed on the screen and it would not make any difference, so talk of 'number' is empty. Or, 'the' soul of GK could die every second and be replaced by a qualitatively indistinguishable soul, and 'I' would never know the difference.

All the best,


Wednesday, September 19, 2012

How Descartes puts the case for doubt in 1st Meditation

To: Aalia S.
From: Geoffrey Klempner
Subject: How Descartes puts the case for doubt in 1st Meditation
Date: 19th May 2008 11:03

Dear Aalia,

Thank you for your email of 10 April, with your University of London Introduction to Philosophy essay, in response to the question, 'In his First Meditation, how does Descartes attempt to show that there is reason to doubt everything one believes?'

You have given a reasonably good summary of the stages of Descartes' argument in the First Meditation, although with one or two gaps which I will explain in a minute.

At the end of the essay, you also offer information which is strictly not required in order to answer the question: the scientific context in which Descartes developed his method -- the experimental work of Galileo which demonstrated that Aristotle's authority was not beyond question -- and also the next stage of the argument, the discovery of the cogito.

Examiners will routinely ignore anything which is not relevant to the question being asked. You can even lose marks. So I would say that the essay would be better without these additions. Concentrate on answering the question, and giving the best arguments that you can in support of your conclusions.

This is a difficult question to tackle because, on the surface, it simply asks for a report on what Descartes says, which is what you give. You do express reservations at one stage -- where Descartes argues that he ought to be more prone to error if the being who created him is less than a perfect deity -- although you comment that you 'do not find his arguments on this point clear enough' doesn't elaborate further.

What the examiner is looking for is critique, and not just description. The examiner wants you to look at the arguments that Descartes offers in support of the proposition that there is 'reason to doubt everything one believes' and assess whether, in your view, those arguments are sound. If you agree with Descartes, you can still put forward objections that someone might have to his argument, and then show how you think Descartes would respond to those objections.

If it is not clear exactly what Descartes is arguing for, then this too is a suitable subject matter for discussion. If there are different possible interpretations of a particular stage in the argument, then you have to give the reasons for preferring one interpretation to another.

Descartes begins with the observation that we are sometimes deceived by our senses, and you offer some helpful examples of this. Actually, your examples raise greater doubts than those that Descartes considers (such as 'round tower looks square from a distance') because the implication is that we cannot even be certain about the contents of our own consciousness -- the very thing that Descartes, in the next Meditation, argues is beyond question!

For example, consider your example of anger. Your friends think you are angry with them, from observing your behaviour, but their judgement is incorrect. You are just excited. However, can't you be wrong about your own feelings? Can't you be angry and not realize that you are, or not angry and think you are angry? Psychotherapists routinely tell their patients that they are making incorrect judgements about what they think they feel, that they are 'deceiving themselves' about their true feelings.

However, to get back to the First Meditation, you do miss an important objection that Descartes considers with regard to perception: that errors of perception (such as the one about the round tower) are corrected by further perceptual judgements. For example, you go closer to the round tower and see that your original judgement was incorrect. That is why Descartes has to consider the more radical doubt regarding being asleep or being awake.

Another point that you overlook is when Descartes raises the possibility that he is a madman, only to immediately dismiss it. Is he right to do this? If he is considering every possibility, including the possibility that he might be dreaming, shouldn't he also seriously consider the possibility that he is mad? If not, why not? What do you think?

The point that you had difficulty with could be explained in this way. Descartes says that God could, if he wished, make him such that he is deceived about even simple arithmetical additions. Now suppose that Descartes was not created by God but by super-intelligent mice (as in Douglas Adams 'The Hitchhikers Guide to the Galaxy'). Even if the mice are very clever they are still fallible. The original Intel Pentium processor had a bug which made it give the incorrect result for certain arithmetical calculations. If my brain was made by mice -- or by Intel -- then how can I be sure that my it doesn't have a similar bug?

One thing that I wasn't clear about from what you said is exactly what is thrown into doubt, by the end of the First Meditation. What does the hypothesis of an evil demon accomplish? A good point to make here is that the evil demon is not just an 'evil scientist' (who attaches wires to your brain and gives you experiences which you wrongly interpret as normal perception). If you've seen any of the Matrix films, you will be familiar with the idea that you might be asleep in a pod, 'dreaming' that you are preparing for your UoL exams.

The evil demon goes further than this. Descartes wants to show that there is reason even to doubt that there exists space, and space-occupying objects. In other words, there is nothing outside the dream, other than the evil demon, no story about lying in a pod, or on a bed or whatever.

Does that hypothesis even make sense? What kind of world would it be, if nothing exists -- no space, no objects, no universe -- apart from my consciousness and the evil demon? That's something to think about.

All the best,


How satisfactory is Spinoza's concept of human freedom?

To: Pearl K.
From: Geoffrey Klempner
Subject: How satisfactory is Spinoza's concept of human freedom?
Date: 14th May 2008 11:38

Dear Pearl,

Thank you for your email of 14 May, with your University of London Modern Philosophy essay in response to the question, 'How satisfactory is Spinoza's concept of human freedom?'

The examiner will give you credit for recognising that there are indeed two questions here and not just one, as you have seen: how satisfactory is Spinoza's account within his own system? and is Spinoza's concept of human freedom 'worthy of the name'?

The first question implies that there might be doubts raised as to whether what Spinoza says about freedom is not only consistent with but necessitated by his philosophical position. However, it is fair to say that you haven't really raised any question here, but merely given a (fairly) adequate account of what Spinoza says.

Aren't you struck by the amazingly bold generalization Spinoza makes about freedom? EVERY inadequate idea equals passion equals unfreedom; EVERY adequate idea equals action equals freedom. How plausible is that? Is that what Spinoza has to say, within his own system, or has he got carried away with enthusiasm?

It is easy enough to come up with examples which seem to support the view about inadequate/ adequate and action/ passion. Daniel Dennett in one of his books (I think 'Brainstorms') gives a recipe for overcoming pain, based on his theory of consciousness, which consists in focusing on the pain actively, making it the centre of one's attention and keeping it there. (Very exhausting!) But it does work. The pain doesn't feel any different but by focusing intensely on it, the pain loses its aspect of 'painfulness'. What makes pain painful is precisely the thwarted desire for avoidance, its inescapability. To overcome that desire is to overcome the pain.

It is also worth noting the very strong influence on Spinoza of the Stoics -- no less important than the influence of Descartes. Virtuous action is free action, action which arises from knowledge. Virtue IS knowledge, just as Socrates said. The most important formula for Spinoza (which you don't state, in so many words) is that freedom is the 'capacity to be determined by reason'.

Knowledge is the ONLY good. There is nothing else to strive for. In striving (acting freely) we are determined by knowledge, seeking knowledge. Our 'conatus' to do what follows from our nature -- as rational beings -- is nothing but the pursuit of rational knowledge, which ultimately amounts to the blissful knowledge of God.

This is truly an 'intoxicating' vision, when one gets into it.

But what about the external side?

You contrast Spinoza's theory with causal incompatibilism, but I get little sense of what causal incompatibilists really believe. What is the difference between a man and a roulette wheel, on their theory?

Today, I have the choice whether to have chips from the chip shop for lunch, or a sandwich. (Lucky me!) This decision isn't determined, so how does it arise? If there is no sequence of causes and effects leading up to the decision how can it be anything but a spin of the roulette wheel, some random event which occurs in my brain?

David Wiggins in 'Towards a Reasonable Libertarianism' (in 'Essays on Freedom of Action' Honderich Ed. RKP) casts doubt on the 'roulette wheel' objection, but doesn't succeed in giving a credible alternative. I've been searching for that alternative ever since I first started studying philosophy (my god, 37 years ago!) and never found it.

It is fair to say that the majority of philosophers tend towards compatibilism. Strawson in 'Freedom and Resentment' has a fairly subtle compatibilist theory. I would have thought that a good question to raise is whether Spinoza's formula, 'Freedom is determination by reason' is an improvement on compatibilism, or perhaps merely a variant. Have you thought about this at all?

The standard compatibilist story, such as you find in A.J. Ayer, is that a person acts freely if they are not 'constrained' by internal psychological factors or external forces. If I push you, or if you are in the grip of some neurosis, your 'action' isn't free. Otherwise it is.

Wouldn't Spinoza have laughed at this negative, apologetic concept of freedom? What would his response have been?

For a start, compatibilist's of Ayer's ilk conceive of action as merely behaviour aimed at satisfying some desire. It could be any desire. There is no difference between 'good' or 'bad' desires on this account, no such thing as a desire which itself arises from 'freedom' or 'unfreedom'. If I want to hurt someone because doing so gives me pleasure, or if I run away like a coward from a situation where my help is urgently needed, my action is no less free than if I do something virtuous or courageous. This is anathema to Spinoza, a 'freedom' which is truly 'not worth the name'.

I hope these comments are helpful to you. I can't tell you what to say in the exam, I can only try to prod you and provoke you into asking questions, and maybe finding ideas within yourself which will show that you are better than the run-of-the-mill candidate. You can do very well -- if you put your mind to it.

All the best,


Spinoza's claim that the one substance is infinite

To: Pearl K.
From: Geoffrey Klempner
Subject: Spinoza's claim that the one substance is infinite
Date: 13th May 2008 13:26

Dear Sachiko,

Thank you for your email of 13 May with your University of London essay in response to, 'Spinoza succeeds in showing that there can only be one substance but he does not show that it must be infinite.' Discuss.

I'm glad your Metaphysics exam went well. You seem to have been very lucky with the questions!

Sometimes students do fail to turn up for an exam at the last minute. It's a waste of the examination fee, I agree, but one has to make a judgement call about whether one is ready.

My advice, when my more nervous students talk of postponing for another year is always, 'Don't let yourself get stale.' You think you would be better in a year's time but in reality you might be worse. If you're wound up and ready to go, then go.

Well, you saved me from having to read a 16000 word fellowship dissertation on legal theory which was on my desk for today.

The first question to ask is what error, in Spinoza's view, is Oldenberg making? What he says seems plain common sense. An attribute is defined as what constitutes a substance's 'essence'. Rationality is clearly essential to being a man or woman. Ergo, two men (or women) can have the same essence. What's wrong with that?

The point to make here, in defence of Spinoza, is that 'an' essential property of a thing isn't the same as 'the' essence of that thing. You and I are rational, and we could not cease to be rational without, in an important sense, ceasing to exist. But rationality is not 'the' essence of S or G. The essence of S identifies a unique individual tracing a path through space and time, as does the essence of G. These essences cannot be the same unless S=G, i.e. unless you and I are the same person.

But this isn't going to get you very far towards monism unless you say something about what, in Spinoza's terms, satisfies the conditions for being a 'substance'. S and G, or generally Aristotelian 'substances' do not. OK. So why not just say that Spinoza isn't talking about substance, he's talking about 'schub-stance'. Spinoza is free to define 'schubstance' in any way he wants. He can define it so that there is necessarily only one schubstance. But so what? The result is merely tautological. Toothless monism.

How can Spinoza's monism be given teeth? Or to put the question another way, what is wrong with talking about Aristotelian 'substances'? There has to be something wrong, in order to enable Spinoza to draw the conclusion that his notion of substance (schubstance) is the *only* acceptable definition.

The original question implies that Spinoza has an argument that there is only one substance from which he deduces that this one substance is infinite. However, you present an argument for one substance which proceeds *via* the claim about infinity: '...the more reality or essence a given being has, the more attributes may be attributed to it. Hence a being absolutely infinite must be defined...'. (What Spinoza puts forward as the 'stronger proof' looks like more or less the same thing, '...the more attributes I assign to any being, the more am I compelled to assign it existence.' What's the difference? I don't see any.)

First, what right has Spinoza to talk of 'more' reality? A thing is either real or not. It exists, or it doesn't exist. A dust mote may be easy to ignore but it is no less real for all that. Nor does merely adding attributes give any reason for feeling 'compelled' to believe that something exists. However many attributes one adds to an imagined entity, isn't sufficient to make it real (unless of course you are convinced by the ontological argument).

I do think that Spinoza has a plausible argument for monism, which does not require belief that the one substance is infinite. On my reading, Spinoza is critiquing Descartes rather than Aristotle. When Descartes considers the relation of God the creator to created 'substances' he reaches the rather extraordinary (for us) conclusion that it isn't enough for God to create stuff, or create S or G. God has to continually exercise his creative power in order to maintain things in existence.

At every moment, you can legitimately raise the question, why does F continue to exist? The naive view would be that things contain their own 'existential inertia'. Once a thing IS, it just keeps on going. But why? Why couldn't things just as well blink in and out of existence? or appear for one moment and be gone forever?

The answer we would give is that the continuance of matter and things made of matter is a consequence of the laws of nature. But in that case, if we are looking at an individual so-called 'substance', then its 'essential nature' -- that which makes it what it is -- necessarily goes beyond the thing itself. Take away the laws of nature and the thing itself cannot be.

If individual Aristotelian substances are not separate from nature, if they cannot exist apart from nature then that is tantamount to saying that they ultimately lack the 'self-containedness' necessary for true 'substance'. That's what's wrong with Aristotelian substance. That's why there can only be one substance.

If this is the line of reasoning which was most persuasive for Spinoza, then it really is an extra question why the one substance has to be infinite. We know from physics that space is finite, not infinite, and according to physics there is, ultimately, only one attribute, material existence. There is no room for an infinite 'God' in this picture.

All the best,


Is personal identity dispensable? / ethics and sociobiology

To: Jeffrey D.
From: Geoffrey Klempner
Subject: Is personal identity dispensable? / ethics and sociobiology
Date: 8th May 2008 12:06

Dear Jeffrey,

Thank you for your two emails of 25 April, with your notes on unit 7 of Possible World Machine, and your second essay, entitled, 'Just who am I?', in response to the question, ''What thought experiments concerning body-duplication show is that the concept of personal IDENTITY is ultimately dispensable.' - Discuss.'


The first question to ask is why we need a notion of identity, in the sense of 'one and the same' or an 'individual', by contrast with identity of attributes. Philosophers sometimes use the term 'token identity' for individuals, by contrast with 'type identity' for attributes.

You state, correctly, that token identity depends upon spatio-temporal position. We track the identity of an individual by tracing its journey through space and time. So far so good.

This doesn't always work, however, because some physical individuals like an amoeba are capable of fission, the resulting two amoebae each satisfy the condition of 'spatio-temporal continuity' with the original amoeba. This straightaway leads to a contradiction with the law of identity, because A (the original amoeba) IS B (the amoeba on the left) and also IS C (the amoeba on the right) but B IS NOT C.

We're not too troubled by this. It's a case of 'say what you like.' Say that an amoeba only 'survives' so long as it doesn't undergo fission. At the moment when fission is complete, the original amoeba no longer exists.

Or, you could define an 'amoeba life history' as the branch of a tree going back to the original amoeba which spawned the countless amoebae. Each one of the resulting amoebae can be identified as a unique life history, even though all the life histories overlap at some point.

This is more or less the choice that faces us if we consider the logical possibility that human beings might divide like amoebae, each resulting individual carrying all the thoughts, memories, feelings and physical characteristics of the individual before the split. Neither of the alternatives is particularly palatable.

Imagine that you face the prospect that this will happen to you. Do you expect to die? Do you expect to survive? In what way?

This is the point where one's Cartesian intuitions come to the fore. I am tempted to say that I, the essential I, cannot be tied to what happens to my body. My identity cannot be monkeyed around with. Maybe I will die. But if I don't, then either I am the one on the left or I am the one on the right.

The problem with this response is that the 'soul substance' which I intend to refer to when I say 'I' has now been cut loose from all physical constraints. It does not occupy a spatial location (if you think it does, like spiritualist's ectoplasm, then we can simply duplicate the splitting scenario). But if soul substance is not spatially located then we have deprived it of the one thing which is capable of distinguishing token identity from type identity.

How can Descartes be confident that he has only one soul? Maybe he has a hundred identical souls. Or maybe his soul 'dies' every second and is replaced by a fresh soul. The fact that we can engage in these speculations shows that *no sense* has been given to the notion of being 'one and the same soul', there is no way to distinguish token identity from type identity for souls.

Natural laws and social laws

Your essay made me think of 'sociobiological' theories of morality. It is not clear from what you have written whether you would approve of this idea. Sociobiologists argue that the objective validity of social laws is a direct measure of their utility in promoting survival -- whether of the individual or of society.

Richard Dawkins in 'The Selfish Gene' explores arguments over whether, or in what sense, a natural 'social law' might develop through Darwinian evolution.

Dawkins dismisses the idea of applying the theory of evolution to societies (along the lines of, the fittest societies survive) because the mechanics of evolution depend on genes, and only genes. Dawkins reports experiments conducted with computer simulations, showing that a gene for altruism cannot survive because the altruists in any society will always be taken advantage of. However, a gene for 'I'll be nice to you if you are nice to me' has a better chance of survival than one which leads to purely selfish behaviour.

So far, so good. The problem is that morality demands a lot more than this.

However, we can also speculate on whether there might be a cultural equivalent of genes. Dawkins calls these 'memes'. Ideas that work, that benefit or stimulate human beings in such a way that those human beings are prompted to propagate those ideas survive and flourish, while other ideas appear for a moment and then are gone.

Is social morality such an idea? You teach your children to be moral, not lie or steal, and the resulting individuals have a better chance of teaching this to their children.

I liked your application of the idea of probability, which is not something which is often talked about. If you make the laws too strict then you are guaranteeing that they will be disobeyed. If they are too lenient then they become ineffective. So, from the point of view of memetics, social morality will be sufficiently demanding to make it more probable than not that a given individual will obey them (you can slide the probability scale from 50 per cent upwards as desired until you reach the optimal point).

In these terms, I would argue that in addition to natural laws and social laws there are rational laws, laws of reason. That is what ethics is about. As the unit on ethics shows, however, it is no easy task to make the case for reason.

Consider the 'Predator' films. Might Predator society be sufficiently different from ours so that 'morality' as we would understand the term has no place? What would such a society be like? How would it survive? The question here is not one that you can answer a priori. We can't be certain that such a society could not exist. Maybe they would find a way, a creative solution diametrically opposed to ours.

Is there something we have seen that Predators have missed? If you feel any urge to say 'yes' then that shows you are not fully convinced of the evolutionary argument as a full account of the nature of what it is to be 'moral'.

All the best,


Friday, September 14, 2012

The soul and our knowledge of non-human animals

To: Kerryn C.
From: Geoffrey Klempner
Subject: The soul and our knowledge of non-human animals
Date: 8th May 2008 11:05

Dear Kerryn,

Thank you for your email of 25 April, with your first essay for Possible World Machine, written to your own title, 'Musings on the soul.'

I agree with you (and with the philosopher Hume) that Descartes was wrong to consider animals as lacking something that human beings have, viz. feelings and consciousness.

Your testimony is especially valuable, because many of the philosophers who argue over the question of animal consciousness have little direct experience of communicating with animals, apart from petting a cat or a dog.

As it happens, one my former students from the time when I gave WEA classes, Islay, is a keen amateur show jumper and has a strongly developed sense of what mood her horse is in today, whether or not she can ask it to jump a particular fence and so on.

Descartes was hampered considerably by the available models for mechanical devices: human ingenuity had reached the point of making life-like twittering birds in cages powered by clockwork. Today, the model is very different -- computer science -- and it is interesting to speculate how different his theory might have been had the science of his day been more advanced. He may well have taken the route of contemporary dualists who assert that all mental events are produced by physical events in the body and brain, rejecting Descartes' theory of causal interaction between a soul and the animal spirits as they pass through the pineal gland.

I like your point about the involvement of the whole body and not just the brain. The brain is not like a piece of clockwork or a car engine which is separate from the device which it 'powers'. Descartes was not unaware of this point, remarking in the Meditations that he is 'not lodged in my body as a pilot in a ship'.

However, the question still remains what we are to make of the difference between humans and non-human animals. One theory put forward by Peter Carruthers (in his book 'The Animals Issue') is that what human beings have, a capacity for self-reflection which Descartes so eloquently describes, depends essentially upon language.

That is not to say that animals lack consciousness, but rather that what they have lacks the crucial dimension of time. Animals live in the present. They carry their memories, for example of previous good treatment or bad treatment, in the form of acquired behaviour -- such as trust or aversion -- but they are incapable of having actual thoughts about any time other than now.

It is easy to get bogged down in arguments over 'how different' animal consciousness is from human consciousness. My own take is that, in the absence of a capacity for linguistic communication, there is a sense in which nothing can be said about how things are from, e.g., the horse's point of view. Any words we use are mere metaphors which may serve as useful heuristic devices but which do not in any real sense 'map onto' the reality which we are attempting to describe. I would go so far as to say that animals are an 'enigma', a portion of reality which we can never fully explore or comprehend.

Thomas Nagel, in his article, 'What is it like to be a Bat?' uses this aspect of enigma to argue against physicalism on the grounds that any physical description would necessarily fall short of capturing how things are from an animal's -- e.g. a bat's -- point of view.

You say that you do believe in the existence of a soul, and also -- more challengingly -- that your ability to fathom another person's feelings is evidence that human beings have souls and are not merely physical.

This raises the question of whether we can imagine what a human being who lacked a soul would be like. I'm a fan of zombie films ('Ten Days After', 'Dawn of the Dead', 'Resident Evil' etc. etc.) and it is interesting to speculate whether there could be something resembling a human being which lacked the soul component. Would they behave like zombies in films?

Suppose I suggested that, in fact, Gordon Brown is a zombie. Gordon's brain and nervous system are 100 per cent responsible for producing all of Gordon's thoughts, feelings, speech, behaviour. Or rather were. Because yesterday, for some unknown reason, there was a malfunction and all Gordon's thoughts and feelings stopped. Now there is just darkness within. However, all of Gordon's behaviour, including what he says, the tiny things you notice on the TV screen or face to face continue, as before. Gordon's brain and nervous system continue to produce all the physical effects that they did before, and only the mental component -- what things are like from the inside if you are Gordon Brown -- is missing.

And, of course, no-one could ever know.

Then again, how do you know that I am not a 'undetectable zombie'? Meeting me and listening to your gut instincts would not make any difference, according to this theory. Unless you believe in some form of telepathy.

One philosopher who has explored the zombie idea is David Chalmers, in Australia. He has a web site and you will find plenty of references on the web to his ideas.

All the best,


Fatalism and determinism; theories of perception

To: Alistair L.
From: Geoffrey Klempner
Subject: Fatalism and determinism; theories of perception
Date: 7th May 2008 12:07

Dear Alistair,

Thank you for your email of 22 April, with your notes on unit 9 of Possible World Machine, and your third essay, in response to the question, 'Compare the theory of fatalism with the thesis of determinism. Is there any way that one could consistently hold a determinist view while denying fatalism, or hold a fatalist view while denying determinism?'.

Thanks also for your email of 6 May, with your notes on unit 10.

Unit 9 and essay

I'm dealing with these together as the same theme runs through both. Possibly, I overestimated the obviousness of the irrelevance of fatalism of the 'divine intervention' variety (the story of Oedipus is a case in point, where the gods will see that the Delphic oracle's prediction will be upheld come what may). I don't find this form of fatalism interesting. If 'someone up there' is determined that X will happen, regardless of what I do, that is not a belief that is amenable to philosophical critique.

By contrast, the fatalism in question is the variety which is fully consistent with determinism (although it does not entail determinism) and does not require divine intervention to outwit me.

However, there is a fallacious argument which makes it seem as though divine intervention magically comes into play. If I am going to be run over by a bus in one minute's time then I am going to be knocked down even if I don't get up from my desk (I'm on the first floor, facing the back of the house in case you were wondering.) If I am not going to be run over, then I am not going to be run over even if I deliberately run out into the main road and throw myself into the path of the next number 76 to Low Edges.

The argument must be valid, because it relies on a theorem of classical logic:

P -> (Q -> P)

This is actually one of the so-called 'paradoxes of material implication'. We find it paradoxical that if P then irrespective of any Q you might choose, if Q then P.

Q can even be -P.

However, no-one would be tempted by the argument, 'If I am going to be run over then even if I'm not going to be run over then I am going to be run over'!

Philosophical fatalism (henceforth, 'fatalism') is a worth while target and far more difficult to refute. The philosophical fatalist accepts that my decision is also fully part of what 'was to be'. The effect of fatalism is the same as determinism: it denies my sense of being an agent, of being 'in charge' of what I do.

However, there is an important difference, and this was what the essay question was intended to bring out.

Fatalism can be true even in a world where determinism is not true. To see this, imagine a godlike observer who sees the future. Past, present and future are already fixed. Determinism is not required. (I think you have seen this point.)

On the other hand, determinism, if it holds, is simply a truth about how things stand now. Someone who denies fatalism can argue that it is logically possible that tomorrow the law of determinism will cease to be true. It is irrelevant that we believe that the laws of nature never change. That is just an empirical belief, and a non-logical truth, if it is true.

Getting down to the nitty gritty, however, determinism and fatalism attack my sense of being an agent in different ways:

-- The fatalist says, 'Everything I do is just something that happens.'

-- The determinist says, 'Everything I do is just something that is caused.'

One response is to argue that there is no inconsistency in an action of mine being something that 'happens' as part of the course of nature, nor in particular in its being something that is 'caused'. This is the compatibilist argument discussed in unit 2.

However, fatalism unlike determinism arguably makes an incoherent claim; this is what I tried to bring out in the second dialogue. It is arguably nonsensical to talk about a proposition about the future being 'true now'. The temporal indexical 'now' adds nothing. All one is left with is, 'If P, then P.' There is no way to coherently state the 'belief' in fatalism. You can't extract a metaphysical proposition from a mere tautology.

Unit 10

Eddington's 'Nature of the Physical World' which was very popular in its day (my father had a copy) is typical of the view which once prevailed -- and possibly still does -- amongst physicists: that I am wrong to think that this desk is 'solid', and that nothing in the external world is at it seems to be.

Russell enthusiastically endorsed this view when he argued, 'Naive realism leads to physics. And physics, if true, shows that naive realism is false. Therefore naive realism is false.' ('If naive realism is false, then if it is true then it is false' is an instantiation of the theorem quoted above.) (I think the reference is in 'Problems of Philosophy'.)

It is against this, that one would deploy the point about 'medium sized objects' and the logical connection between the concept of perception and human agency, which you are onto in your account of a capacity to 'model' the world which we have evolved for practical purposes.

This is realism about perception (and direct realism, not a representative realism which puts us behind a veil of perception) but it is not 'naive' realism. On the contrary, the arguments in its favour are philosophically sophisticated. The upshot is that we do, in fact, see things as they are. Grass really is green. It is irrelevant that one has an explanation in terms of cones in the retina and different light wavelengths. All that may be true, but does not undermine our normal perceptual beliefs.

The worry about an 'illusion created by non-material minds' is a different point, which goes back to Descartes' 'evil demon' argument from the first Meditation (to which Berkeley responded by turning Descartes' argument upside down -- there is nothing to be sceptical about because there's nothing God can do to make 'matter' exist).

I'm sorry, I don't have any specific references about 'scale' in relation to the philosophy of perception. David Hamlyn 'Sensation and Perception' (RKP, unfortunately out of print) is an excellent book on the history of theories of perception.

Historically, the first effective defence of non-naive, non-representational realism about perception came with the 'new realism' in the first part of the 20th century, in particular in the work of the much neglected philosopher Samuel Alexander ('Space, Time and Deity'). Unfortunately, much of the gains were lost with the rise of logical positivism and phenomenalist theories of perception. It wasn't until the 50's, with the rise of 'ordinary language' philosophy in Oxford and in particular J.L. Austin ('Sense and Sensibilia') and Wittgenstein's later work at Cambridge ('Philosophical Investigations') that a better, more sophisticated defence of realism was developed.

There is a strong temptation to think that an account of perception depends on empirical investigation into the processes 'behind' what we see, both in the external world and in our own bodies. You've said a number of things that depend upon what scientific investigation has discovered about how visual perception works.

A good question to ask -- in the spirit of an investigation into possible worlds -- is how differently alien beings could be constituted and yet still perceive things 'as they are'. If they are the same size as us, and have roughly the same interest in satisfying needs and avoiding harm, then it not beyond the bounds of possibility that we could agree about much of what we see even if our internal processes are very different. That shows something.

All the best,


Can two objects be in the same place at the same time?

To: Pearl K.
From: Geoffrey Klempner
Subject: Can two objects be in the same place at the same time?
Date: 1st May 2008 11:03

Dear Pearl,

Thank you for your email of 1 May, with your University of London Metaphysics essay in response to the question, 'Can two objects be in the same place at the same time? Justify your answer.'

This is really a question, as I read it, about the notion of 'identity under a covering sortal concept' as discussed by David Wiggins in his book 'Sameness and substance', which is based on his earlier monograph, 'Identity and spatio-temporal continuity'. You wouldn't have heard of the latter (which I studied as a student) but the other book is quite well known.

There is an issue about 'strict' identity, with some philosophers refusing to allow that ANY identity over time can be strict but this seems to defeat the purpose of having a notion of identity in the first place.

I agree with the way you pose the problem: there is a prima facie clash between the criterion of 'being in the same place at the same time' and satisfying Leibniz Law.

First major howler, two red balls which have all their attributes in common are still two red balls not one! (There is a story about how Leibniz got the courtiers at Hanover to search through the garden to 'prove' his thesis of the identity of indiscernibles by failing to find two perfectly identical leaves. Leibniz knew full well that his theory didn't require this.)

The point is it all depends whether you include spatial relation amongst the properties quantified over. If so, then Leibniz Law holds, but not otherwise. If being at a certain place IS a property of red ball A then this is a property that red ball B can't have.

Oops, but now it looks as though our two original criteria are collapsing into one another, as 'being in the same place' is now one of the properties considered in Leibniz Law!

However, there is still a tension here as demonstrated by the example of the clay and the statue. The question is whether being in the same place is *sufficient* for identity or only necessary but not sufficient.

Second major howler: we are not considering the lump of clay before it was made into a statue (when it looked like a lump!) but only after. In that case the lump of clay is exactly the same shape as the statue, how could it not be? So what are the grounds for saying that the lump of clay and the statue are not identical?

The grounds for saying this is that the lump of clay and the statue have different *criteria of identity*. Their identity comes under different sortal concepts, 'material' and 'artifact'.

Proof that they are different (by Leibniz Law) is that the material existed when the statue did not yet exist, and will exist after the statue is destroyed.

(There was a dispute between Peter Geach and Wiggins over the question of so-called 'relative identity'. Geach held that this example showed that the very same objects could be 'the same X' but not 'the same Y': e.g. A and B are the same material but not the same statue. There is general agreement that Geach was wrong about this: either A is identical to B or it isn't.)

What there can't be, according to Wiggins' account of 'identity under a sortal concept' is two objects which both fall under the same sortal in the same place at the same time.

What are your intuitions on this? I was at a lecture by Wiggins where he gave the example of two pennies. I have one in each hand, moving them backwards and forwards until they touch. Then, magically, they merge and part again. Is that logically possible? During the time when they merged (let's say completely) were there two pennies or only one? Does it matter if the weight is different?

As for the ship of Theseus, I think that this is a red herring (sorry about the mixed metaphor). It illustrates the point about identity under a sortal concept, which reinforces what Lowe says: the concept 'same artifact' supports the process of continuous repair and replacement, but not storage of parts and reassembly.

What one would say about the reassembled ship is that according to the criteria of identity for the sortal concept 'artifact', the ship came into existence when it was assembled. This does grind against our intuitions somewhat, because you don't want to say that your computer which was taken to bits while you were having your room decorated is a 'new computer' when it is reassembled (even if it does work better). The difference, however, seems to depend on the smallness of the 'bits'. If the plastic and metal were recycled and the material used to build a computer, then you would definitely say it was a 'new computer', even if it was exactly the same construction as the old one.

All the best,


Descartes' case for doubt in the first Meditation

To: Alex W.
From: Geoffrey Klempner
Subject: Descartes' case for doubt in the first Meditation
Date: 1st May 2008 09:52

Dear Alex,

Thank you for your email of 23 April with your University of London Introduction to Philosophy essay in response to the question, 'By what means does Descartes attempt to show that there is reason to doubt everything one believes?'

I generally don't like marking, but I have marked undergraduate scripts and I guess my approach would be the same as most examiners: by the end of the second paragraph, I have already formed a provisional opinion about the mark that an essay merits, which is then adjusted up or down as I encounter things I like or dislike.

Your essay did well. The first thing that impressed me was that you noticed that there are two senses to the notion of a 'reason to doubt everything one believes'. Several of my students have done this essay but you are the only one to make this simple but relevant point.

I liked the fact that you recognized that it is an astounding proposition that one should identify the foundations of knowledge and subject these to doubt.

A good point that 'to say, "we should doubt everything" sounds rather certain in itself,' I only wish you had developed this a bit further. Descartes advocacy of a method of systematic doubt is based on considerations which Descartes thinks are persuasive. In other words, he is arguing rationally. Later, when we considers that he might be mad he pushes aside without further discussion the consideration that he might not be capable of rational argument. Is he right to do this?

Later still, of course, he brings in the evil demon which threatens to undermine this assumption still further. If the evil demon can do anything, he can make Descartes believe he is arguing rationally when in reality he is following an incoherent stream of consciousness. Descartes is setting up his sceptical scenario in order to prepare the ground for the Cogito and his argument for the existence of a God who would not deceive him into thinking that his ideas are 'clear and distinct' when they are not. However, contemporary critics pointed out that the argument leads to a circle (the 'Cartesian Circle') because Descartes assumes the validity of clear and distinct ideas in order to prove the existence of God.

The point to make about the madman is that sanity consists in two components, the capacity to think rationally -- to draw reasonable conclusions from given evidence -- and the capacity to perceive things more or less as they are, i.e. not be a habitual sufferer of hallucinations. However, the claim that one needs to assume rationality if one is to argue at all bears unequally on these two aspects. The worry about hallucinations is no less easy to dismiss than the worry that he might be dreaming.

You say that what Descartes says, 'implies there is a certain 'sane' or essentially correct way to see the world.' Despite what I have said above, I'm not so sure about that. To consider the possibility that perception might be unreliable is not to assume that there could ever be reliable perception. Maybe the world is chaotic and perception is impossible.

I'm not sure I followed your point about Locke. Like Descartes, Locke assumes that we are capable of rational reflection. Locke would not deny that Pythagoras' Theorem is a product of reflection which gives knowledge of the world which is, in an important sense, independent of sensory evidence.

Descartes considers the possibility (finally) that he might make errors even about things he thinks are most certain, such as a simple addition of two numbers. God could make him go wrong, if he wanted to. I'm not sure what your view is about that. It is a problematic turn, as you observe, because it threatens to subvert the background assumption that howsoever one might doubt, one is capable of following a rational argument. (Hence thel infamous 'Cartesian Circle' referred to above.)

So, finally, we get to the evil demon. The evil demon is not just a Matrix-style scenario or evil scientist. The difference is that Descartes is questioning the very existence of an external world as such, the existence of space, and objects occupying it -- any objects. For all he knows, there might just be an evil demon 'out there' and nothing else! So I would disagree with your claim that it is 'perfectly analogous' to the brain-in-a-vat scenario.

All the best,


Tuesday, September 11, 2012

McTaggart's proof of the unreality of time

To: Pearl K.
From: Geoffrey Klempner
Subject: McTaggart's proof of the unreality of time
Date: 1st May 2008 08:59

Dear Sachiko,

Thank you for your email of 30 April with your University of London Metaphysics essay in response to the question, 'Does McTaggart have a convincing argument for the unreality of time?'

I was quite impressed with the way you were able to assimilate some of the main arguments over McTaggart's notorious proof, including D.H. Mellor's 'defence' of the reality of time in his book 'Real Time'.

Given the constraints of an hour timed essay, if you could succeed in demonstrating your knowledge as shown here (even though most or all if it is derived from text books rather than reading the original books/ papers) you would get a decent mark. You seem to understand what the arguments are about (no mean feat!) and that's the important thing.

However, with my examiner's hat on, I would be wondering whether or to what extent you have really grappled with this problem yourself, rather than just reading and comparing texts. I'm saying this because the reality of time was one of the first problems that gripped me when I was first contemplating taking a degree in philosophy (many, many years ago).

As it happens, I have made my own contribution to the debate (although 'not a lot of people know this'). That's OK, because my solution is purchased at a price which many philosophers would find too dear -- accepting the reality of a 'metaphysical contradiction'. See the relevant chapter of Naive Metaphysics.

Mellor puts his finger on the essential paradox about time, in the very course of seeming to dispense with the main defence of the A-theorists: that human action is essentially temporal and would be unthinkable in a universe constituted wholly of a before-and-after series of events.

In doing so, he is effectively arguing (as I would say) for the unreality of time, not its reality. Without the A-series you don't have time. The very notion of defining the meaning of statements referring to time or times by means of statable truth conditions already does away with what is essential to time.

Let me put this another way. How do you define 'now'? Is it the time that GK is typing the words, 'How do you define 'now'?' in a Word document? Yes. It is also the time of a million other events all over the world (including your preparing for your exams at this very moment, I imagine). However, what I have just written is false. In the time it took to write another couple of sentences, now is no longer the time that GK was writing the words referred to above. It is 'then'. This is just another, simpler, version of McTaggart's more elaborate 'vicious regress' argument.

It is impossible to define to real times. Words slip off. All you can do is name events and compare their position in the B-series with other events. Our own view of ourselves as agents as actively involved in the world may be 'true', but it is a truth that cannot be stated or described as it is, but only indicted in general terms (as I have just done).

McTaggart believed that the ultimate nature of reality is not the A-series or the B-series but something he called the C-series. Not a lot of philosophers discuss this today. That is because most assume (as I have done) that if you are a B-theorist who thinks that the A-series is dispensable or definable in terms of the B-series then, in effect, you accept McTaggart's argument (or the main force of his argument) for the unreality of time.

Michael Dummett has an interesting take on the reality/ unreality of time which is relevant to understanding McTaggart. In his paper, 'The Reality of the Past', Dummett attacks the idea that knowledge of meaning is knowledge of truth conditions, advocating in its place a Wittgensteinian-style theory which puts the emphasis on how speakers are actually trained to use temporal vocabulary (sometimes referred to as 'verification conditions'). A realist view of the past, according to which propositions about the past have truth conditions which can be satisfied independently of whether we are capable of coming to know that they have been satisfied, is equivalent to belief in the unreality of time, that is to say, in Dummett's view, a failure to grasp the reality of the present moment and the flow of time.

All the best,


Nature of philosophy and the theories of the Milesians

To: Larry B.
From: Geoffrey Klempner
Subject: Nature of Philosophy and the theories of the Milesians
Date: 30th April 2008 12:45

Dear Larry,

Thank you for your email of 20 April, with your first essay for the Ancient Philosophy program, in response to the question, 'What does the examination of the arguments and theories of the first philosophers show us about the nature of philosophy?'

This is an excellent start. I am pleased to see that you are using available reference material as well as following the argument of each unit.

It is a very tricky question to say exactly what distinguishes philosophy as a branch of inquiry from other inquiries. This is the main point of the question: what is distinctive about the approach taken by the philosopher? is there anything that arguments or theories or approaches that we term 'philosophical' have in common, which distinguishes them from those which are not philosophical as such but, say, scientific, or psychological, or historical etc.?

In other words, is there a useful definition of philosophy, or, if not, can we still grasp the essential nature of philosophy from looking closely at what the first philosophers did?

You remark on three aspects of Milesian philosophy: (1) they were concerned with what is real, and the distinction between reality and appearance; (2) as Jonathan Barnes observes, they were also the 'fathers of rational thought', the first to 'subordinate assertion to argument and dogma to logic'; (3) they put forward theories about the world and where it came from, based on observable fact but constrained by reason.

However, it might be thought out that these three points apply just as well to physics. We know that the first three philosophers were also the first three physicists. Yes, the discovery of the possibility of doing physics was a philosophical discovery. But, beyond that, what was it that they did that justifies the term 'philosopher'?

You quote my claim that one of the things that the Milesians had in common was the belief that 'the world conforms to reason'. However, this has more than one possible meaning. We can certainly say that they proceeded on the assumption that the most rational explanation is the one that is true.

Why indeed should that be the case? why put such faith in reason?

Imagine a very clever criminal who deliberately sets up the crime scene in such a way that detectives thinking rationally and using all the available evidence will find that only one possible conclusion can be drawn, that X was the murderer. Some cases never get solved, and sometimes innocent people get successfully framed. Descartes, in the First Meditation, imagined an evil demon who has set out to deceive me even when I use my rational faculties as carefully as possible. How can he know that the universe was created by a benevolent God rather than by an evil demon? Surely puny man has no chance against an evil demon.

The point of this is that in taking the view that the world is bound eventually to yield to rational inquiry requires a certain kind of faith, the faith of the philosopher in the power of reason. It is part of that faith that there is no cosmic master criminal or evil demon. The first philosophers didn't talk about God (if we leave out Xenophanes.) Yet they believed that it you use your powers of reason correctly and responsibly you will uncover what there is to be uncovered about the ultimate nature of reality.

In unit 2, I also argued that there is also another aspect to the idea of the world 'conforming to reason', which is exhibited in Anaximander's explanation of why the earth is suspended in space. Even without making empirical observations, as the scientist does, it is possible using philosophical argument to establish conclusions which hold as necessary truths, irrespective of observation. This is the strongest in which philosophers have believed that world 'conforms to reason'.

The laws of logic would be a relatively uncontentious example of this. They hold irrespective of the facts. The 'principle of sufficient reason' or the law of causality, on the other hand, is a principle which cannot be justified by logic alone. Is the principle of sufficient reason just something we believe? or is it necessarily true, true in all possible worlds?

And what about wisdom? I don't have a lot to say about that because on the basis of the evidence available, the first philosophers do not seem to have been particularly interested in wisdom as such, or the proper conduct of life based on philosophical principles. They were enthusiastic theorists and speculators. Of course, we don't know for sure. However, on the basis of the written evidence it seems that it wasn't until Socrates came on the scene, that the emphasis shifted to the practical use of reason in ordering our lives and 'caring for the soul'.

All the best,


David Hume on the idea of causation

To: Scott B.
From: Geoffrey Klempner
Subject: David Hume on the idea of causation
Date: 30th April 2008 11:53

Dear Scott,

Thank you for your email of 21 April, with your University of London Diploma essay in response to the question, 'What explanation does Hume give of the idea we have of a cause?'

Whenever you get a question like this, it is always a challenge to find something more to say than merely giving a precis of what the philosopher says. This is a point I may have made before. In fact, although you stick close to the text, you do attempt to provide your own take on what Hume is trying to do, in giving two definitions of 'cause'.

Generally, with a question like this, you will get more marks if you are able to offer a critique of the account which a philosopher gives. If you disagree or think that the account is inadequate in some way, then explain the reasons why. If you agree, then you can still offer objections that someone might have to the account and then, on the philosopher's behalf, give replies to those objections.

You say, 'It seems that the first definition is based on when we judge a cause to produce an effect. the second definition is based on why we judge a cause to produce an effect.' There is something right about this, but it needs to be made more precise.

The first part would be correct if you said, 'the first definition is based on when we *correctly* judge a cause to produce an effect.' The point is that Hume is stating what it is for it to be true to say that A caused B.

The second part has a certain ambiguity, because the phrase 'why we judge a cause to produce an effect' can refer either to the causal process in the mental machinery -- in Hume's case the story about impressions and ideas -- or to the justification which we give in support of our statement. To use a contemporary term, it is the difference between the 'logical space of causes' and the 'logical space of reasons'. Hume does not ever deny that there is a logical space of reasons. He can't do because all through the text he is giving reasons of one sort or another. His official theory, however, is that human rationality is ultimately explained by the theory of association of ideas.

The definition offered by Hume in terms of contiguity, priority and constant conjunction would, to use the contemporary jargon, be regarded as an attempt to give the 'truth conditions' of causal statements, or the 'necessary and sufficient conditions' for a causal statement to be true.

Why isn't that enough? If, and only if, it is true that A is contiguous with B, occurs prior to B and A and B are constantly conjoined (in the sense of a true universal generalization, not restricted in space or time) then A *is* the cause of B. There is nothing more to be said, on Hume's account. There is, of course the question of how we can ever know that A has caused B, and as you remark Hume gives a list of rules for 'judging causes and effects'. The upshot is that if ever A occurs without B then according to this definition of 'cause' we must assume there is something different in this case that distinguishes it from previous cases of A causing B that we have observed.

However, Hume still hasn't explained why it is that we *think* that there is more to causation than this, why we succumb to he philosophical prejudice or illusion that there exists some kind of intrinsic or necessary connection between A and B.

Hume's explanation, as you point out, follows his theory of ideas and impressions. However, it is not clear that he has succeeded in explaining how this extra factor arises.

If the first, 'philosophical' account is correct then applying causation to the mental realm, the second account of how an impression calls up a lively idea (i.e. the belief that B will follow, based on our perception of an event of type A) is exactly what you would expect. We are naturally disposed to form beliefs, based on our perception, and this natural disposition leads us to form true beliefs, at least enough of the time and provided that we are careful in applying the rules that Hume proposes.

But this still doesn't explain why we feel unsatisfied with the original definition. To parody Hume, looking into my mind I don't find any idea of 'necessary connection'. As a good Humean about causation, I believe that causal statements are, ultimately, true in virtue of universal laws and nothing more. Am I missing something?

So, your answer to the essay question will depend on how for you agree with this claim. In other words, in addition to giving Hume's explanation, the examiner would expect you to say something along the lines of (1) why you think *he* thinks that he needs to give the explanation that he gives, and (2) whether according to his own terms you think he has been successful.

All the best,


Donnellan on referential and attributive descriptions

To: Graham C.
From: Geoffrey Klempner
Subject: Donnellan on referential and attributive descriptions
Date: 25th April 2008 11:29

Dear Graham,

Thank you for your email of 10 April, responding to my comments on your essay on truth, your email of 17 April with your University of London Logic essay in response to the question, 'Can the sentence ‘The man over there drinking Martini is a philosopher’ be true even though nothing satisfies the definite description? Justify your answer.' and your follow-up email of 19 April.

My take on the 1949 Analysis article is that Strawson was using the vernacular of the day. The crucial point is, 'What commends the word as, e.g., a confirmatory device is its economy. By its means we can confirm without repeating.'

Worry about ideology is somewhat simplistic. Why should philosophers agree? It is better that we are working with multiple paradigms than if we all agree on the same paradigm. You try one thing then another, until something works. (And I'm not proposing 'pragmatism' as a paradigm either.) Philosophy is not a science.

Regarding the parochial 'the'. Russell and Frege shared the view that natural language is not a reliable guide, it is messy and somewhat chaotic, having evolved over time to meet practical needs. This was a bone of contention between Russell and the early Wittgenstein, whose view was that every statement of natural language has a precise analysis, and indeed this is how it gets its meaning (so when I say, 'the cup is on the table' I am in fact asserting a massive disjunction of atomic propositions, giving every possible alternative location for 'the' cup).

When Russell wrote in the introduction to the Tractatus that Wittgenstein was interested in describing a logically ideal language, Wittgenstein strongly objected. He was describing the logic of our actual language, which lies hidden beneath the deceptive surface, the actual machinery that makes it work.

This is relevant to understanding current debates over definite descriptions. Russell knew that descriptions are needed for logic and maths, where for example one makes a statement about 'the' class which satisfies such and such a condition. You never know when you might encounter a paradox (!) which proves that the class you were referring does not exist. To preserve logic (i.e. truth conditions) Russell's analysis is indispensable.

A relatively contemporary proponent of this approach is W.V.O. Quine who talks of 'regimentation' of natural language for this or that purpose, rather than analysis. Many would regard Quine's 'Two Dogmas of Empiricism' as having kicked into touch any idea that there are definitive answers to questions about 'the' meaning of this or that expression in natural language.

This is very much a 'potted account'. There is much, much more to say. But let's now look at your essay:

I had to laugh about your example of 'The cat is on the mat' meaning 'I want a divorce'. But, seriously, we are in very different territory if the question is one of the significance of an utterance in this sense. Consider a psychoanalyst overhearing a conversation where there is a great deal to read between the lines.

We want and need an account of the content of an utterance, based on the actual words used together with any indexical elements ('this', 'that', 'now', 'I', 'she' etc.). That much is agreed. As soon as you bring in a 'pragmatic' dimension then you have taken a step towards the cat on the mat case. We want this too, but first we need a clear account of the semantics.

Pragmatics is not an adequate substitute for an inadequate semantic theory.

Here's an even better example of referential use of a description. I happen to know that the man in the corner is drinking a Oxyiac, a rare non-alcoholic herbal essence made my Monks in Tuscany (I made this up). However, as it is extremely unlikely that you have even heard of this beverage, I deliberately use the false description 'Martini' because all I'm doing is trying to secure a reference, and the drink has the same pale yellow colour. So what if you go home musing over the fact that philosophers like to drink Martini? Did I lie? he is a philosopher, isn't he?

Doesn't that strike you as extremely weird? have we so little regard for the truth?

Without going into the business of rival semantic accounts (and if you read, you will discover there are further alternatives besides simple Russell and simple Donnellan) it is not difficult to produce examples which push our intuitions the other way. Of course, someone who has a full grasp of the context would know whether or not the information the speaker intended to convey is correct or otherwise. It may indeed be the drink not the profession of the drinker which is the focus of interest, but you couldn't tell just from hearing one sentence.

What a person says -- the content of their utterance -- and the information they intend to convey are not always the same, as your cat on the mat example shows.

However, Donnellan might reply that we are missing the point. All he was concerned to do was show that natural language has a strong contextual/ demonstrative element. Whereas the use of words can be described by rules, human gestures escape the net of formal theory. One conclusion to draw from this is that there can never be a fully adequate 'semantics'. Even so, I would argue, this is no excuse for ditching Russell.

All the best,


Thursday, September 6, 2012

'Inside' and 'outside' the mind - Descartes' case for dualism

To: Kathleen C.
From: Geoffrey Klempner
Subject: 'Inside' and 'outside' the mind - Descartes' case for dualism
Date: 21 April 2008 12:31

Dear Kay,

Thank you for your email of 10 April, with your second essay for Philosophy of Mind, in response to the question, 'Examine Descartes’ argument in the Sixth Meditation for the distinction between mind and body. What objections can you conceive being raised against the argument? How would you attempt to defend the argument against those objections?', and your email of 15 April resending your first essay which you originally sent (attempted to send) on 26 March, in response to the question, 'Select one line of argument from units 1-3 and express it your own words. (Imagine you are explaining the argument to a friend who knows nothing about philosophy.)'

Inside and outside

It is funny that you should choose this, because (as you realize) the 'argument' in question is in fact not an argument I am putting forward as part of the ongoing inquiry but rather a view or belief -- a 'hypothesis' -- which is being carefully set up for reductio.

The 'inside' is not like this. If it were, one may deduce from the argument, then it would indeed be the case that we could not be sure that we enjoyed qualitatively similar experiences, or indeed that some of 'us' were not in fact behaviorally indistinguishable zombies.

You say, 'Let me offer you one certainty. When I experience looking at blue, I cannot be mistaken. It is logically impossible for me to be wrong. Sadly the certainty doesn't last.'

Wrong about *what* exactly?

Wrong that it is 'blue'? No, because we are not talking about the colour of the sky or blue ink but rather the colour of my private impression, 'the colour that the things you and I call "blue" looks to me'.

In what sense is this a 'colour'? Is there any chance that your friend who knows nothing about philosophy might begin to waver on this point?

There are things I could have said here. For example, one temptation would be to assert that colours are *only* in us. Out there, there are just atoms and molecules, light waves and the laws of physics. The sort of thing Bertrand Russell would say. Naive realism tells us that there are blue 'things'. But, as Russell famously argued, 'Naive realism leads to physics; and physics, if true, shows that naive realism is false. Therefore naive realism is false.'

In other words, philosophical analysis reveals that 'blue' is necessarily a property of sense data, and nothing but sense data.

Wittgenstein, Russell's eager student, saw the fatal flaw in this theory. We have taken a word from its normal context, and applied it in a situation where all the normal criteria for its application have been stripped away. All that is left is the immediate certainty that 'this is this'. The problem is, that we are not content with calling this 'this'. We imagine that we can describe it, relate it to other thises.

Contra Russell, the only truly 'logically proper' name would be one which we applied strictly on one occasion. I put 'S' in my diary once and never again. Nor can I recall the 'meaning' of 'S' because any such mental object is different from the original mental object to which the label 'S' was attached.

Most commentators assume that Wittgenstein denies the existence of the 'private object'. But I wonder whether there might not be another interpretation, whereby the private object, the unnameable, unrecallable 'this' exists all right, only nothing can be said about it. (And a 'nothing would do as well as a something about which nothing can be said.')

Descartes' argument for mind-body dualism

Most commentator's take Descartes' argument in Meditation 6 to involve an implicit recapitulation of his argument in Meditation 1 to the effect that it is logically possible that my mind exists and no body exists. It is strange, however, that he doesn't say so explicitly, but gives the impression that he is relying on an unargued intuition that mind and body may be 'clearly and distinctly' conceived as separate.

One objection you consider is to the effect that different people have different 'clear and distinct' perceptions. You connect this to the argument in Meditation 1 by saying that 'he has told us of an experiment in doubt that he has conducted... there is no guarantee that if we repeat the experiment we will come to the same conclusion.'

How would you defend Descartes against this objection? He wasn't conducting an empirical experiment, Descartes would say, but rather doing a piece of logical analysis. The point of the analysis is to show that there is nothing in the subjective character of conscious experience that 'proves' the existence of physical reality. A subjective experience is what it is and has no implications outside of itself. That is the immediate corollary of the fact that the quality of subjective experience as such cannot be doubted. The evil demon is just thrown in to make the point more vivid.

This is the 'problematic idealism' which Kant approved of because it is phrased in terms of a challenge: a challenge which Kant believed he could meet (in the 'Refutation of Idealism' of the 2nd edition of the Critique of Pure Reason). Kant aside, the point here would be that Descartes is issuing a challenge. To meet the challenge it is not enough to say, 'I performed the experiment and I got a different result!' You have to do a Kant and prove, e.g. that experience is 'only possible on the condition that it is interpreted as experience of an external world'.

Descartes does state at one point that my mind is not lodged in my body as a 'pilot in a ship'. However, he is right in holding that there is no logical inconsistency between this view and his empirical speculation that the pineal gland is the one physical location of the body which is sensitive to changes in a non-physical, non-located soul substance. It isn't an objection that it doesn't *feel* like that. It is indeed a problem for physics (easier to solve in Cartesian physics than in Newtonian) but not a crushing logical objection.

One objection you didn't consider was along the lines of the 'contingent identity' thesis advocated by the 'Australian materialists' Armstrong and Smart. Sure, mind and body *might have* been distinct (in some other possible world) but in fact the best scientific evidence shows that they are not. By Occam's Razor, we should choose the simpler hypothesis -- identity of mental and physical events -- over the more complex.

Kripke's 'Naming and Necessity' which originally appeared in 1972 played a considerable part in reviving the mind-body debate, by arguing that if 'mind' and 'body' are viewed as 'rigid designators', then their identity must be necessary, effectively blowing the contingent identity thesis out of the water. That is why the only effective way to engage with dualism is to engage with Descartes' arguments directly.

All the best,


Role of causes and effects in scientific explanation

To: Yasuko S.
From: Geoffrey Klempner
Subject: Role of causes and effects in scientific explanation
Date: 21 April 2008 11:24

Dear Yasuko,

Thank you for your email of 11 April with the second version of your University of London Methodology essay, 'A scientific explanation is the explanation of effects by causes.' Discuss.

This is a very clear and well structured answer which shows that you have a good grasp of the issues. I have nothing to say about sections 1-3. However, section 4 was a bit brief and 'breathless', and I am not sure that we understand the role of human agency in the same way.

You are right to say that Hume analyses causation on two levels. This is how I would explain it:

1. On the objective level, a causal statement of the form 'A causes B' is true by virtue of a universal law. Hume avoids the question of how one states ceteris paribus conditions. This is a big problem in itself because A and B are particular events, whereas 'an event of type A' and 'an event of type B' are general terms which necessarily lack all the properties of actual events A and B. That's why one can't simply say, 'All cases of A are followed by B'. Arguably, precise ceteris paribus conditions can never be adequately stated. However, Hume can still assert that there 'exists' a law, albeit unstatable, by virtue of which any given causal statement is true, if indeed it is true. There is nothing else in reality, no 'influence' or 'necessary connection' or whatever.

We should observe that the idea of universal law is an extremely powerful notion. We are talking about a 'truth' which applies at all times and in all places. That does not go without saying. No-one can ever know that such a law is true, because human beings are finite. At best, we can only have inductive evidence for its truth.

2. Human beings are interested in causes. That also does not go without saying. We form our empirical beliefs by means of a process whereby an impression (e.g. a stone thrown at a window) calls up a 'lively idea' of the expected consequence (e.g. the window breaking), according to certain principles which Hume explains. This psychological account of how beliefs are formed is indeed a causal explanation (a point on which Hume has been wrongly criticized; in fact, he is being perfectly consistent in talking of causes and effects in the mental realm of ideas, then analysing these in terms of 1.).

If one imagined a race of intelligent trees, then it seems that they could do this too. For example, they learn from experience to form the lively idea of rain from the impression of the sky becoming dark with clouds.

However, the point I was trying to make about agency is more contentious than anything Hume claims. It is that in order to form the full-blooded notion of a 'cause' it is necessary to be a physical agent, capable of intervening in the world, and not just a passive observer thinking (= 'mental agency') about what it observes.

It would seem to follow that if we (per impossibile) were not physical agents, then the only kind of 'explanation' we could be interested in is one which was perfectly symmetrical with prediction. Do you agree with that? I'm not sure I do.

How is it that we are so good at identifying 'the' cause of something, when we are dealing with complex conditions? Consider the role of causation in the law: what was it that 'caused' the car crash, the stormy weather, the road works, the lazy mechanic who didn't adjust the brakes properly, the inattentive driver, the reckless pedestrian, etc. etc.? All these conditions were required for the car crash to occur, but we don't say that it was 'caused' by the weather or the road works.

One might try to apply J.L. Mackie's definition of 'cause' in terms of an 'INUS condition', an 'insufficient but necessary part of an unnecessary but sufficient condition'. But exactly *which* part? that's the question. (For Mackie, see the Stanford Encyclopedia article on 'Probabilistic Causation'.) The law is concerned to punish and deter, so we are led to identify the bad action or decision by a human agent as 'the' cause, although as in this case, we may have to accept that there are several 'causes', which played a lesser or greater part.

Salmon's account seems to have a lot going for it because we are interested in 'mechanisms', and this goes deeper than simply the ability to predict. Wouldn't intelligent trees be interested in mechanisms too? Yes, up to a point. Mechanism gives detail, in terms of which one can distinguish deeper, fuller explanations from more superficial ones. Maybe this is enough and one doesn't need to factor in the extra variable of human physical agency.

So, you see, this is not such an easy issue to resolve. I think that the thing to say is that the fact that we are physical agents is significant in analysing our concept of a 'cause', but it is not totally clear whether, if counterfactually one removed the element of physical agency, there might still be a role for a notion of cause which goes beyond the simple D-N model as Salmon claims.

In analysing causation we are not dealing with a 'cut and dried' issue but a deep philosophical problem. In an exam, it is perfectly OK to recognize this, to admit that your view is not settled and that you are aware of conflicting considerations. If I had to answer this question, I guess that is what I would say.

All the best,