Friday, June 28, 2013

Hume on the 'fiction' of personal identity

To: Mark S.
From: Geoffrey Klempner
Subject: Hume on the 'fiction' of personal identity
Date: 6th April 2010 12:08

Dear Mark,

Thank you for your email of 30 March, with your essay for the University of London Modern Philosophy: Descartes et. al. BA module, in response to the question, ''The identity which we ascribe to the mind of man is only a fictitious one' (Treatise, I. iv. 6). Did Hume deny the unity of mind, or simply advocate a new view of what it is?

In my response to your last essay on Hume's two definitions of 'cause', I placed fairly heavy emphasis on Hume's naturalism -- his vision of a 'theory of human nature' which located the mind in the world of nature, as something whose behaviour is explained by laws. That this is only half the story becomes apparent both in Hume's discussion of 'on scepticism with regard to the senses' and in his account of the 'fiction' of personal identity. In brief, Hume is unable to reconcile the naturalistic view with his methodological solipsism.

It is interesting that you only mention the possibility that 'ownership' of perceptions depends on association with a 'particular body'. This is actually A.J. Ayer's view, rather than Wittgenstein's. It's a glaringly obvious solution to the problem of the unity of a bundle of perceptions at a time, and also the identity of that bundle over time. But it is a solution which is unavailable to Hume, for the reasons which you give.

The unity of a bundle of perceptions is a breeze, if we follow Hume's assumption of 'mental transparency' as you term it (despite what you quote Garret and Pears saying). We simply define a relation, 'co-presence' which is symmetrical, reflexive and transitive. All the perceptions in the universe are automatically divided into bundles, where A and B belong to bundle X if and only if A is co-present with B. No bundles can overlap (because then they would be the same bundle). Problem solved.

Identity over time is more tricky, because all we have are present perceptions. The bundle of GK's perceptions that existed a minute, or a year ago, is present in the current bundle as a memory impression. Note that this is not a story about overlapping bundles. We have already seen that bundles can't overlap.

An immediate consequence of this definition, however, is that it becomes perfectly conceivable that you and I should undergo the experience of changing bodies. I wake up in Australia and you wake up in the UK. Methodological solipsism makes this possible.

Again, as we've discussed, there is a solution which preserves a modified version of solipsism/ mental transparency, namely Kant's. What you quote as the 'mind-world separation problem' is actually the solution: as the early Wittgenstein expresses it in the Tractatus: 'I am my world'. Experiences are necessarily interpreted in terms of a theory according to which they result from the movement of a subject (which can be 'embodied' or a disembodied point of view) through a spatial world. The finesse is that we are, in effect, solving a large number of simultaneous equations: any given sequence of experiences can be explained in more than one way, we can invent any number of possible worlds which would explain their occurrence. But as the sequence gets longer, the number of alternatives decreases.

The unity of the self -- both synchronic and diachronic is, on this view, a necessary feature of the theory. It doesn't need to be explained or defined further. It is simply a necessary condition for the possibility of experience.

The only problem with this solution from Hume's point of view is that it doesn't require the assumption of naturalism. The mind does not have to be part of nature (because, e.g. it can be a mere disembodied point of view -- although Kant never actually says this explicitly). The theory is consistent with naturalism, but it is also consistent with Kant's theory of the phenomenal and noumenal worlds.

Again, with regard to the 'inadequacy problem', the difficulty for Hume is that it looks like he is forced to identify what there is with what we can know, on the assumption of methodological solipsism. Locke and his notion of observable properties flowing from a real essence would be a solution, but one which Hume's principles will not allow him to embrace.

It is easy to conclude that Hume was right when he composed his Appendix, that he realized that his theory of the self was inadequate. (I liked what you said about the anxious patient.) But I think he was being over-scrupulous. His theory isn't that bad. The alternatives (like Kant, or Ayer, or the later Wittgenstein) have their own cost. The beauty of Hume's theory of the self is in its purity and simplicity.

All the best,


Plato's form of the Good in the Sun, Line and Cave

To: Egor S.
From: Geoffrey Klempner
Subject: Plato's form of the Good, in the Sun, Line and Cave

Dear Egor,

Thank you for your email of 25 March, with your one hour timed essay for the University of London Plato and the Presocratics module, in response to the question, 'What is he role of the Form of Good as characterized in the analogies of Sun, Line and Cave?

At a mere 520 words, this essay is again rather short.

The question is really asking you to consider, or raise difficulties with understanding how Plato conceived of the Form of Good. There's quite a lot of mystery regarding this. Where Plato refers to the Form of Good he always resorts to metaphorical or analogical language. It is as if the Form of Good is something the philosopher can ultimately only *see*, once they have engaged in the dialectic. Words always fall short of the reality of what the Form of Good is, as an entity in itself.

Regarding the analogy of the Sun, you state, 'It's indeed the clearest statement of what Plato takes the Form of Good to be that he gives in all of his writings. It can even be argued that he needs it for the whole theory of Forms to hang together.' The statement in question is that knowledge of the objects of philosophical inquiry is revealed by the 'light' of the Form of Good, just as objects of sense perception are revealed by the light of the sun.

However, what an examiner wants to know is how it is that what Plato says about the Form of Good supports the theory of Forms. Here you should at least try to express a view. What's your best take on this? What does the theory of Forms (without the Form of Good) lack which the Form of Good supplies? I'm not asking you to guess, but rather to venture a more or less plausible interpretative hypothesis.

Regarding the analogy of the Line, you suggest that there is a problem in applying the image of the line to the unique case of the Form of Good. 'One solution could be to imagine Good lying at the very end of the line -- to where one ascends after a particular form, such as one of those mentioned' (sc. Justice, Courage, Knowledge).

This doesn't tell us a great deal. One possible thought is that approach to the Form of Good is asymptotic, the closer you get the more intellectual effort you need to make. However, you never actually make it to the end of the line.

Regarding the analogy of the Cave, the most plausible candidate for what you describe as the 'false inauthentic something' taking the role of the fire which casts shadows against the wall, would be the heavenly body we know as 'the Sun'. All the objects we view by means of sense perception are merely 'shadows' compared with the true objects of knowledge illuminated by the Form of Good. In other words, The Form of Good bears the same relation to the actual heavenly body known as the Sun, as the 'Sun' in the Cave analogy bears to the 'fire'.

Adding up the conclusions from the analogies of the Sun, Line and Cave doesn't take us very far. However, I think that it is fully legitimate to interpolate what we know, indirectly, about the Good from what Plato says elsewhere about the Forms.

A typical Socratic dialogue will go as follows. Socrates asks his interlocutor to define some moral virtue, e.g. courage. The interlocutor offers a definition. Socrates then objects that, according to the definition offered, 'courage' isn't always a good thing. For example, consider the definition, 'Courage is advancing in the face of the enemy'. Socrates points out that in certain circumstances this is mere foolhardiness (e.g. when you are heavily outnumbered and have no chance of success) not courage.

In other words, the constant assumption behind the various attempts to define the moral virtues, is that they are something that it is good, without qualification, to have. In defining the moral virtues, we are, indirectly, adding to our grasp of the Form of Good, even though no attempt is ever made to define Good as such. This gives substance to the idea that the Form of Good 'illuminates' the objects of philosophical knowledge.

I cannot stress strongly enough that in an examination, you have to push yourself. If you think that you've said all that you have to say, and what you've said only adds up to 400 or 500 words then you need to push harder. If you are not sure of something, say it anyway, and add that you are not sure. If you can think of objections to what you've said, then give those objections.

A very useful form is, 'One might think that ABC, but the objection to that is XYZ'. In that way, you get the chance to state a view and also take it back, so you're covered both ways. You will either get credit for expressing the view, or credit for expressing the objection, or possibly both.

All the best,


Dialogue between Thales, Anaximander and Anaximenes

To: Charles R.
From: Geoffrey Klempner
Subject: Dialogue between Thales, Anaximander and Anaximenes
Date: 1st April 2010 11:27

Dear Charles,

Thank you for your email of 25 March, with your first piece of work for the Ancient Philosophy program, 'An Imaginary Dialogue Concerning the Fundamental Nature of All Things', featuring Thales, Anaximander and Anaximenes.

I enjoyed reading this. The few little touches that you added to give the dialogue a sense of realism worked well, and the three Milesians came across as very likeable chaps.

One question that immediately came to mind concerned Anaximenes question in response to Anaximander's example of the craftsman making a wheel for a cart, 'Are you suggesting that the gods may have followed rules while constructing the world and the heavens? But how can the gods be subject to rules? It is the gods who make the rules and, therefore, how can they be subject to them?'

The idea that the Greek gods were responsible for constructing the universe is wildly anachronistic, let alone the idea that they authored the rules whereby the construction was made possible. Xenophanes was the first Greek philosopher to consider what are the necessary and sufficient conditions for a true 'God', and even he only claims that God 'sees and moves all by the power of his mind'.

The gods on Mount Olympus are creatures, albeit 'supermen' by our modest standards. They 'make the rules' in the sense of controlling the lives of men, punishing those who defy them, but they are not creators of the universe. The very idea of a first act of creation, as such, is way ahead of Greek thinking at this stage. It is only with Aristotle, that we get the first argument which recognizes the need to halt a vicious regress of explanation -- the argument for an 'unmoved mover' -- and even that stops short of the idea of creation ex nihilo, which you have put into the mouth of Anaximenes.

Heraclitus' concept of the eternal Logos is perhaps the first real anticipation of the God of Judeo-Christian theology. 'In the beginning there was the Logos.' Yet, for Heraclitus, there is no 'beginning of the universe' as such, at least, no evidence for this in his writings. The world, the material expression of the Logos is itself 'an eternal fire, kindling in measures and going out in measures'.

Thales' reference to 'the use of our god-given reason' is anachronistic for a similar reason. The gods didn't give us our powers of reason. The gods were 'given' their great powers, and we were 'given' our lesser powers. Only, there was no 'giver' as such.

However, I do think that the analogy with the craftsman and the cart is a great idea and in itself very plausible. Greek technology reached its heights, arguably, with the design and construction of the trireme, a precisely engineered and designed fearsome weapon of naval warfare. Recent experiments in constructing triremes according the original design (or, what can be figured out regarding the design from pot decorations, paintings etc.) show the Greeks could not have relied merely on rules of thumb. Similar conclusions can be drawn regarding the magnificent examples of Greek architecture.

What was central to the discussions which may very well have taken place between the Milesians were the notions of 'cosmos' and 'chaos', together with a broader notion of teleology (which I have mentioned in a previous communication) according to which there is a positive nisus or force towards cosmos and away from chaos in the universe, although this has to contend with its opposite (which we would now recognize as the principle of entropy) i.e. the tendency for things to break, scatter and fall into ruin. It was not until the atomists that the scientific credibility of teleological explanation came into question.

Much of your dialogue covers things we have discussed before. However, you venture some plausible hypotheses concerning the selection of water, and air. Thales: 'Furthermore, in its purest form water is transparent and, as a completely transparent substance, may be present and yet unseen. This may account for those objects which seem to be completely dry. It may account for water's apparent absence in fire.'

In the unit, I raise the question what it 'means' to say that water is 'really' fire, as opposed to saying that fire is 'really' water. In both cases all you are saying is that there is some fundamental stuff, which under some conditions takes the appearance of water, and under other conditions takes the appearance of fire (there is no logical implication here of a neutral basis such as the apeiron, although that would be one possible way to extend the idea).

Your thought is different. There's water everywhere, and it IS water. Only you don't always see it because of its transparency. Just as it is hard to see the wateriness of water in snow, or the misty steam from a cooking pot. Good!

I also like the lucid way you contrast 'explanation in terms of the conflict of opposites' with 'explanation by means of condensation and rarefaction'. The point to make here is that the two seemingly contradictory hypotheses were combined in the philosophy of Heraclitus. Fire 'kindles' and 'goes out' in measures just like Anaximenes' rarefaction or condensation of air, but in the case of Heraclitus this essentially involves a constant tension or conflict between merely *apparent* opposites.

All the best,


Knowledge, justified true belief and self-justifying beliefs

To: Anna H.
From: Geoffrey Klempner
Subject: Knowledge, justified true belief and self-justifying beliefs
Date: 1st April 2010 11:27

Dear Anna,

Thank you for your email of 2 March, with your essay for the University of London Epistemology module, in response to the question, 'How should one respond to apparent counterexamples to the view that knowledge is a form of justified true belief?', and your email of 29 March, with your essay in response to the question, 'In order to amount to knowledge a belief must be justified. So, unless some beliefs are self-justifying, there is no knowledge.' Discuss.

Counterexamples to knowledge as justified true belief

Recent discussions of epistemology have been dominated by the Gettier problem: in fact one could say that Gettier's 'paradox' defines the task for the contemporary epistemologist.

The question asks, 'how should one respond', and I take this to mean that the examiner is looking to you to make a case for your favoured solution, against alternative solutions.

In your discussion of Gettier, you mention two key points: the cases where justified true beliefs fail to be knowledge are all cases where the justification includes a false belief, and/ or where it is a mere accident that P is true relative to the justification for P.

According to your reading of these requirements (or this joint requirement) we are ineluctably drawn towards scepticism. My justification for believing that P can be ever so good, or ever so persuasive. Yet there is still a chance that I have made some false assumption somewhere. Even if P is true, it does not follow that I know that P, because it is still possible that the truth of P is an accident relative to my justification for believing that P.

However, it is important to distinguish the challenge of traditional scepticism from the kind of scepticism which potentially arises out of the Gettier paradox. The starting assumption is that there is lots of knowledge around. One does not require infallible justification. All we ask is that the justification is sufficient to give us the 'right to be sure' of P. I am right to be sure of the truth that I haven't won the lottery this week, as I checked the numbers on the TV. However, if I had checked the numbers and discovered that I had won the lottery, I would not feel that I had the right to be sure until I had double-checked, and checked again. This is perfectly rational behaviour.

So, I check the numbers, discover I haven't won, and moreover my belief that I haven't won is in fact true. So I know I haven't won. The problem is, if you try to apply extra conditions -- like 'no false assumptions' -- in order to meet the Gettier challenge, you get pushed right back into scepticism. In other words, having seemingly resisted the traditional argument for scepticism, we are forced back to a sceptical conclusion by the Gettier paradox. The revised definition of knowledge is such that we can never be fully satisfied that the required conditions are fulfilled.

Some would think that this is not a very satisfactory conclusion. However, you are perfectly entitled to defend your view, if this is what you believe. The essay would make a stronger case, however, if you considered alternative approaches offered by the various 'externalist' accounts of knowledge such as reliabilism, or Nozick's account of knowledge in terms of 'tracking truth'.

In terms of length, if you can achieve something like this in the exam, you would be doing reasonably well. 800-1000 words is a good target to aim for.

Self-justifying beliefs

In your essay, you focus on the foundationalist view, according to which some beliefs are indeed self-justifying, and therefore capable of being used to justify those beliefs which are not self-justifying.

A full answer to this question would have to consider the challenge which a coherentist about knowledge would mount to this argument. According to the coherence theory of knowledge, there can be knowledge even though no beliefs are self-justifying, because beliefs form a stable network where beliefs are mutually justifying. What, if anything, do you think is wrong with that idea? At the very least, you need to state why you are ruling out the coherentist response.

What exactly is the foundationalist committed to? You refer to Bertrand Russell, who held that the foundations of our knowledge of the external world are propositions about sense data. (See e.g. Russell's lectures on Logical Atomism.) However, you don't mention this, instead referring to Russell's claim that 'a theory of truth must be such as to admit its opposite, falsehood.' I am not quite sure of the significance of this point here. My beliefs about my own sense data are certain, immune from doubt, incapable of being false. That's just what makes them suitable as foundations for knowledge. Isn't it?

But what kind of 'truth' can this be, if a belief about sense data cannot, in principle be false? It would be like shooting an arrow at a target, where the target is attached to your arrow. You can't miss. But if you can't miss the target, you can't 'hit' it either. Clearly, Russell did not seriously consider this point, as a potential objection: if he had, he would have been led to reject the sense datum theory. (The argument I have just given is, in effect, a version of Wittgenstein's argument against the possibility of a private language.)

Wittgenstein, in his later work 'On Certainty' makes a powerful case that certain basic propositions do not need justification, even though, unlike alleged propositions about sense data, we can conceive of, or imagine their being false. He argued that to merely imagine that a belief might be false is not yet to 'doubt' its truth in any meaningful sense. I can imagine that a yawning chasm has opened up just behind my chair. But as I get up and turn to cross the room I do not entertain the slightest notion that there is any danger of falling down into a bottomless pit. I know without looking that the floor is safe to walk on.

In the 'Philosophical Investigations', in response to a sceptic who asks, 'If you are certain aren't you merely shutting your eyes to doubt?' Wittgenstein responds, simply, 'They are shut.'

Wittgenstein's view supports a modified (non-Cartesian, non-Russellian) foundationalism. We do justify beliefs by other beliefs. But some beliefs do not require justification, because they are like the hinges on which our view of the world around us turns. Wholesale questioning of our basic beliefs is out of the question. Our eyes are indeed shut.

At the end of your essay, you introduce a new idea, from Hegel's 'Phenomenology of Perception'. In the argument which you quote, Hegel adds that it would be like 'trying to catch a bird with a lime twig...surely the bird would laugh our ruse to scorn'. (I assume Hegel is referring to some old-wives tale.) I am prepared to buy the idea that this connects to the later Wittgenstein's view that basic beliefs can be justified without requiring justification by other beliefs. However, you don't really spell this out sufficiently to make the case. I would have liked to have seen a few more words on this particular point.

All the best,


Wednesday, June 26, 2013

The justification of deductive reasoning

To: Craig S.
From: Geoffrey Klempner
Subject: The justification of deductive reasoning
Date: 31st March 2010 11:18

Dear Craig,

Thank you for your email of 22 March, with your essay for the University of London Logic BA module, in response to the question, 'Can there be a convincing justification for deductive reasoning?'

This is an excellent essay with which I have few real disagreements. I am pleased to see that you give consideration to Dummett's British Academy lecture, 'The Justification of Deduction' which is an important contribution to this topic.

I'm a little bit wary of the idea that deductive reasoning has a pragmatic justification. I'm reminded of the story of the American state (I can't remember which one -- the story could be apocryphal) where a law was passed decreeing that the value of Pi would henceforth be taken to be 3. The idea was to make trigonometric calculations used in the building industry simpler, with less likelihood of error. The result was, as you would expect, an unmitigated disaster.

If you break the laws of logic (or in this case, Euclidean geometry) the result is likely to be unfavourable. So it is good policy never to break a law of logic if you can help it. However, this way of looking at the matter suggests that there might be some more obscure laws of logic for which the attitude of the legislature of the unknown US State was indeed appropriate. From a pragmatic perspective, you can only judge by results. This seems wrong. (From dim memory, I think there might be something along these lines in one of Lewis Carroll's 'Alice' books.)

Or think of it as analogous to deliberately making a bad move in chess. Sometimes the consequences can be better than if you had made a good move, because your opponent is tempted to overreach himself in punishing your 'mistake'. I can imagine Reginald Perrin's boss saying, 'I didn't get where I am today without breaking the laws of logic!'

The question asks whether there is a convincing justification for 'deductive reasoning' as such. You are right to focus on this. Formal systems attempt to encapsulate our intuitions about the validity of deductive reasoning. However, in some areas of logic, this can be contentious: e.g. the increasing number of systems of modal logic. How do you justify one person's intuitions about formally valid modal inferences against another person's contrary intuitions? Let's say that both systems have adequate consistency and completeness proofs, using different models of possible world semantics.

This is admittedly not quite the same point: with modal logic we are talking about defending particular instances or forms of deductive reasoning against the challenge of rival forms of deductive reasoning, rather than the justification of deductive reasoning as such. However, I think an examiner would consider this sufficiently relevant to the question, if only to throw the broader question into relief.

Dummett in his British Academy lecture focuses on the clash between classical and intuitionist logic. (There is more on this theme in his article, 'The Philosophical Basis of Intuitionist Logic' in 'Truth and Other Enigmas'.) The key point of dispute concerns the Law of Excluded Middle, or equivalently, the double negation elimination rule. Arguments which use Reductio ad Absurdum to prove a proposition P, by deriving a contradiction from the double negation of P are valid in classical logic but not in intuitionist logic. How does one resolve this dispute?

Dummett would say that you have to engage in the hard work of constructing a theory of meaning for the language and defending it against rival theories of meaning: in this case justifying a theory of meaning in terms of verification or proof conditions against a theory of meaning in terms of truth conditions.

On Dummett's view, the only adequate justification for a verification conditions theory of meaning is one which applies globally, and thus constitutes a global justification for intuitionist logic against classical logic. So here we are doing more than just providing an 'explanatory' argument. People who reason using classical logic are wrong. They are reasoning fallaciously. Whereas people who reason using intuitionist logic are not reasoning fallaciously.

From a broader, historical perspective, metaphysics and logic have always been bound up together, ever since Parmenides. Perhaps the most famous (or notorious) case is Hegel's apparent denial of the law of non-contradiction. In present times, we have systems of dialethic logic, which claim to be in some sense more accurate portrayals of the true nature of reality than classical or intuitionist logic. In a messy, enigmatic, paradoxical world, it pays to be less rigid in one's thinking.

One other thing you could have mentioned is Quine's image of a network of beliefs interacting with experience at the edges, while the laws of logic are situated in the middle. In his 'Two Dogmas' essay, Quine notoriously argues that no belief is immune to revision, not even laws of maths and logic. Insofar as we have not needed to revise our logic in the face of experience, it could be said that the laws of logic have an empirical justification. However, this justification is only ad hoc or temporary. Quantum mechanics is one area where classical logic has (allegedly) been put under pressure as a result of scientific advance.

All the best,


Science and the claim that observation is theory laden

To: Chris M.
From: Geoffrey Klempner
Subject: Science and the claim that observation is theory laden
Date: 30th March 2010 13:15

Dear Christian,

Thank you for your email of 21 March, with your essay for the University of London Logic BA module, in response to the question, 'Scientific claims cannot be objective, because their justification relies on observation, and observation is theory-laden.' Discuss.

You cover a lot of ground in your answer to this question. You look at Quine's image of a network of beliefs on which experience impinges at the edges, you mention Kuhn and incommensurable paradigms, and inferences from the familiar illusions of perception to the effect that all seeing is in some sense 'seeing as', as well as Fodor's defence of 'cognitively inpenetrable perceptual modules' (pointing in the other direction, towards a theory-neutral perceptual content), then finally at the end you throw in Grover Maxwell's idea that the observation-theory distinction is relative not absolute.

The traditional example is the Church's opposition to the use of the telescope in the early part of the 17th century. When the telescope was pointed at the Moon, it clearly revealed mountains and craters -- but only to those who accepted the theory of how telescopes work. To churchmen who 'new' that the Moon had a smooth, glassy surface all the observations proved is that the Devil was at work confounding our perceptions.

Now, anyone could look through the telescope and draw, accurately, what they saw. How is it that the churchmen didn't see what was there to be seen?

There is a point to make about the remarkable human capacity to refuse to believe what we see (because we 'know' we can't be seeing it). And it is also tempting to hook this up with Kuhn's idea of incommensurable paradigms. However, if one looks at 'real science' what happens is not that one researcher refuses to 'see' an observation made by another researcher. Rather, problems with a theory are first revealed as 'anomalies' in observations, with the defenders of the old paradigm insisting that these are not significant, while the critics of that paradigm insist that the anomalies are significant.

How do you decide questions of 'significance'? What we are talking about is not so much observations as such, as patterns of observation, or observation report, over time.

Thus, the original question, could be posed again: 'Scientific claims cannot be objective because their justification relies on recognition of the significance of patterns of observation over time, and what is or is not significant depends on a prior theory.' This looks less threatening, if only because the claim that an observed anomaly is not significant looks less and less plausible, as the anomalies increase.

However, there is another factor to take into consideration, which is that the design of experiments is heavily dependent on theory. You more or less make this point. There are always less chances of finding what you were not looking for, than there are of finding what you were looking for. The point here, however, is that it IS possible to 'not find what you were looking for'.

What this doesn't allow for, of course, is the possibility that there are two (or more!) theories which explain all the observations equally well. According to theory 1, the observations confirm theory 1, while according to theory 2, the observations confirm theory 2. In that case, there really is a problem of objectivity.

But how often does that occur in 'real' science? It is very rare that we have one theory that is fully consistent with the observations, let alone more than one. In a possible universe where there were lots of equally good incommensurable theories we would have strong grounds for doubting the objectivity of scientific claims. But the mere thought that our universe might, theoretically, be like that isn't in itself sufficient to raise doubts. The situation here can be compared with classic sceptical scenarios, where the mere fact that you can imagine some wild sceptical hypothesis isn't itself grounds for doubt.

In other words, in order to make the original statement that 'scientific claims cannot be objection because... observation is theory-laden' plausible, it is necessary to imagine possible worlds which are significantly different from the actual world. If the universe is the creation of a Cartesian-style 'evil demon' then there might be all sorts of ways in which honest investigators might be tricked into thinking that a theory had been 'confirmed' when in fact it had not. But that isn't our universe, at least, not so far as we have been able to observe (!).

These are just some thoughts which you might find helpful (or provocative). I think an examiner would be impressed by the amount of material which you have covered. If there is a criticism to make, it is that I don't have a clear picture of your all-things-considered view on this.

All the best,


Hume's two definitions of causation

To: Mark S.
From: Geoffrey Klempner
Subject: Hume's two definitions of causation
Date: 30th March 2010 11:56

Dear Mark,

Thank you for your email of 21 March, with your essay for the University of London Modern Philosophy: Descartes et. al. BA module, in response to the question, 'Why did Hume provide more than one definition of 'cause'? How do his definitions differ, and what is the significance of those differences?

I find myself disagreeing both with you and with Garrett on this question. I agree that it seems excessively strained to regard the two definitions of a cause -- an object followed by another 'where all the objects similar to the first are followed by objects similar to the second', and 'whose appearance always conveys the thought to that other' -- as 'extensionally equivalent'. But I am also not convinced by your explanation, according to which the two definitions are merely intended to give two 'incomplete' views of the same object, that of the 'ordinary person' and that of the 'philosopher'.

Hume's statement that 'it is impossible to give any just definition of cause except what is drawn from something extraneous and foreign to it', looks, superficially, like an admission that there is something down there, a secret connection which philosophy cannot describe other than indirectly. But this is clearly wrong. There's nothing 'down there'. Lawlike connection is all there is, there is nothing else to 'causation'.

Except for the fact, of course, that human beings are gifted with the ability to discern at least some of the lawlike connections that obtain in nature. That is because of our natural constitution, and in particular the lawlike generalizations which describe the workings of the human mind.

I find this an incredibly deep idea. To appreciate its significance it is necessary to go back to Descartes, and the evil demon scenario. Descartes is not only interested in the extreme case where the evil demon gives me 'experiences' of a world which does not really exist. The question of the possibility of scientific knowledge crucially turns on the human capacity to form causal beliefs -- to infer explanations -- and the seemingly miraculous correspondence between the way the world works and the way our minds work in figuring out how the world works.

This is a miracle, for Descartes, because the mind is not part of the natural world. There are no limits on how a soul can generate thoughts within itself because souls don't have 'workings', they are simple and indivisible, not made of 'parts' in the way that the objects of our perception and judgement are. The solution has to be that 'God is no deceiver'. Souls are designed to form true representations of the world, provided that human beings exercise their powers of judgement responsibly.

With Hume all that is swept away. Human beings are part of the natural world, and the human mind obeys natural laws -- laws of cause and effect -- just as the objects of its perception do.

If you look at the problem of defining cause from this point of view, it is clear that there is no alternative for Hume but to deny the 'secret connection'. God is out of the picture. All we have are the principles of the association of ideas to go on.

It would be legitimate to say that in giving his two definitions, Hume has one eye on the philosophical 'illusion' concerning the nature of causation which he is rejecting. The second definition forms part of a naturalistic explanation of the aetiology of that illusion. However, if this is all Hume wanted to say then it would be curious that he gives the two definitions in the way that he gives them.

I am not sure about your 'huge pile of objects' analogy. What is real, are the lawlike connections that render science possible. We can leave aside for now the question which I've raised earlier concerning how 'realist' we should be about the 'truth' of these lawlike statements. 'Cause' is difficult to define because of the inherent vagueness in the idea of 'similarity' -- or, what amounts to the same thing, the impossibility of fully defining 'ceteris paribus' conditions. The first definition covers all the 'causes' there are, nothing is left out, but even if per impossibile we knew all the laws of nature, there would still be a gap between that knowledge, and the knowledge of all the causes in the universe, because of the inherent fuzziness in the definition of a cause.

The second definition explains why we need that inherently fuzzy notion. Human beings are in the world, interacting with it on a piecemeal basis, so what comes first in terms of knowledge is particular causal statements rather than general laws.

Perhaps this is what you were trying to get at in relating the two definitions of cause to what Hume says about 'natural' and 'philosophical' relations. There is something important here to explain, namely, how it is that through the medium of language human beings have been able to extend the capacity for causal reasoning with which they are naturally endowed. Hume's rules for judging causes and effects is the first step in that explanation. Nature provides us with the capacity to develop language (or 'form ideas'), which in turn expands our powers of explanation. That was the main thing that interested Locke. But Hume saw far deeper into the problem of how it is that human beings are able to acquire knowledge of the external world.

All the best,


Hobbes' concept of the laws of nature

To: Pearl K.
From: Geoffrey Klempner
Subject: Hobbes' concept of the laws of nature
Date: 26th March 2010 12:57

Dear Sachiko,

Thank you for your email of 19 March, with your essay for the University of London BA Political Philosophy module, in response to the question, 'How should we understand Hobbes' concept of the laws of nature? In what sense, if any, are they laws?

This essay is for the most part lucid and well argued, altogether an very good exposition of Hobbes. However, you are right about what you said in your email, 'I have a feeling I have missed a big chunk of something somewhere'. There is a drastic tail-off at the end of your essay, which leaves unanswered the main question underlying how Hobbes understands 'Laws of Nature' and in particular how Hobbes' view differs from that of Aquinas, given that both philosophers claim that these laws are in some sense grounded in God's will.

You pick on the central issue, the question whether self-preservation is itself a divinely based law (Aquinas) or merely a fact about human nature, but the one thing you needed to do was relate this to Hobbes' notion of Laws of Nature as not only objectively based in God's will but also rationally compelling independently of what, if anything, we know about God.

The whole question of how ethics can be based on divine command given the objection of circularity -- are moral laws right because God commands them or does God command them because they are right? -- is a fascinating one: you might be interested to look at a piece I wrote for my blog, 'Tentative Answers' about Geach and the Euthyphro dilemma. See:

For philosophers who follow Aquinas' view, it is sufficient that we know what God commands us to do. The Holy Scriptures provide ample information on that score. Hobbes' view is more complex: on the one hand, the laws of nature are divinely based, and that is what constitutes their objective grounding. But on the other hand, human beings are perfectly capable of deriving these laws for themselves by means of their God-given capacity for reason. Later, Kant was to argue for a similar conclusion, while conceding that belief in the existence of God can never be justified by reason but must be left to faith.

Hobbes *needs* the assumption of the principle of self-preservation as a given fact, a descriptive, non-moral axiom, in order to derive the laws of nature as 'theorems', as you call them. The challenge for politics, as Hobbes sees it, is to explain how it is that men can agree to live by laws which limit their freedom of action, to the benefit of all.

It is not enough that each man can see this benefit. That is the whole point about the so-called 'prisoners dilemma'. You give the example of Caligula as evidence backing up Locke's criticism of Hobbes' argument for the need for an absolute sovereign. But Hobbes would say that this just misses the point about the dilemma. If you get a group of people together -- e.g. parliamentarians in a Western democracy -- what laws, what sanctions, keep the lawmakers in check and prevent each man pursuing his own 'glory' to the detriment of others?

The answer is that there is an absolute sovereign, in effect, in the state. The institutions of the police, army and judiciary combine to form a power which no individual citizen can defy. You can't fight the law. If you take human beings in a Hobbesian state of nature, there is no way that they can create such a complex structure from scratch. An absolute monarch is the only solution that can work. If there is a criticism to be made of Hobbes on this point, it is that he did not recognize the possibility that the absolute power can evolve into what we have today, where the actual monarch is a mere figure head and power resides with the elected government.

But ARE human beings prior to any political organization in the 'state of nature' which Hobbes describes? This is a vulnerable point in his case, because he is basing this on a mere empirical hypothesis, for which he has no hard evidence. Human beings have evolved as social beings. Arguably, the conditions for an idea of justice can already be found in any human family, however primitive. On this view, Hobbes' attempt to account for the laws of nature -- the rules of justice and morality -- solely on the basis of self-preservation or self-interest is a heroic failure. We don't have to pull ourselves up by our boot-laces. As social beings, even in a primitive society, we are already where Hobbes wants us to be.

I apologize if I have strayed into expressing my own views on this question, but you can see this as just one possible way -- contentious though it may be -- of how the gap in your otherwise commendable exposition might be filled.

All the best,


Friday, June 21, 2013

Hume's theory of belief and the role of rationality

To: Alistair L.
From: Geoffrey Klempner
Subject: Hume's theory of belief and the role of rationality
Date: 25th March 2010 12:24

Dear Alistair,

Thank you for your email of 19 March, with your essay for the University of London BA Modern Philosophy: Descartes et. al. module, in response to the question, 'What account did Hume give of the nature of belief? Can he provide a coherent account of why some beliefs are more rational than others?'

This is a great question which you have made a valiant attempt to answer, but I don't think that you do answer it satisfactorily.

The key question is why, if there is no rational basis for beliefs about cause and effect -- if all causal beliefs are themselves just the effects that the impact of information from the outside world has on our brains -- some of these 'effects' should be privileged above others as being more 'rational'? Belief isn't rational, period. It's just something animals and human beings have evolved in order to help us navigate our way through a perilous world.

Though notions of evolution or survival of the fittest are not explicit in Hume, he would no doubt readily assent to the idea that the utility of our natural disposition to believe, as in the case of non-human animals, is proved by its success. But that would hardly count as a definition of 'rationality'.

But, first, what is 'belief'? You cite Hume's definition of belief in terms of forcefulness, firmness, vivacity. I think it is important (especially in view of the above) to connect this to action. Hume recognized that it is the vivacity of ideas which moves us to act, and he gives as his reason that such ideas by becoming more vivacious acquire the same capacity to move us, physically, as the impressions of our senses. In this sense, beliefs are like perceptions at one remove.

I do think you could say a lot more about this than you have written in your answer. In a two part question you can assume that examiners will be looking for an equal effort in respect of each part (though this doesn't necessarily mean that you have to write the same number of words). It is important for the answer to the second question (the nature of rationality) that you give an adequate answer to the first (the nature of belief).

With regard to the second question, you cite a key piece of evidence in Section XV of the Treatise, 'Rules by which to judge of causes and effects'. A lot more could be made of this. Why should we agree to Hume's rules? If you conduct careful meteorological observations and conclude that there will be a storm tomorrow, while I consult sheep entrails, what makes your belief 'better' or 'more rational' than mine?

Perhaps an even better example, Hume's 'Dialogues Concerning Natural Religion' mounts an impressively powerful case against religious belief. Hume observes that human beings are 'credulous' and that we cling to beliefs for all sorts of irrational reasons. But why should we be persuaded by his arguments? This is especially pertinent given that beliefs regarding a deity are not put to the test of experience (or at least have not been up to now).

Hume was a supremely rational and clear-thinking philosopher. But what do we mean when we say that?

What the question is really asking you to do is derive a definition of rationality of belief which is consistent with Hume's account of impressions and ideas, and in particular his account of 'reasoning about causes and effects'.

A key piece of evidence is something you observe near the end of your essay: 'Feelings sourced from your emotions are relatively crude interpretations of the world that can provide the motivation to act without involving your reasoning faculties.' You go off somewhat at a tangent after making this remark. It is true that our emotions do have an important role in survival. But Hume isn't concerned with that. What he is concerned with is that our emotions lead us to believe all sorts of things which are not rationally based. The story of human credulity is the story about how easily our emotions are manipulated.

From this perspective, reasoning about causes and effects is the paradigmatic form of rational belief formation. The beauty of Hume's theory is that the rules for judging causes and effects are themselves the product of the very same process of formation of vivacious ideas through repetition of experiences. This is made possible by the human power of memory and language.

A dog cannot reason about causes and effects, it can only react to experiences. Whereas we have the ability to resist the impulsive response to an experience, through imaginatively placing the scenario in a wider context, where the belief in question forms part of a mosaic pattern of beliefs representing our acquired knowledge of the world. It is language, and through language, logic, which enables the formation a system of beliefs, connected by relations of justification or inference to the best explanation.

That is not a bad explanation of rationality. Will it do? Is Hume's account ultimately coherent? I leave that for you to decide.

All the best,


Berkeley's attack on abstract ideas

To: Matthew M.
From: Geoffrey Klempner
Subject: Berkeley's attack on abstract ideas
Date: 24th March 2010 12:15

Dear Matthew,

Thank you for your email of 15 March, with your essay for the University of London BA Modern Philosophy: Descartes et. al. module, in response to the question, 'Why was it important to Berkeley to attack the theory of abstract ideas? How successful is his attack?

This is a fair answer to the question, and also a good length for a one hour examination answer. However, it is a bit short of the 2000-2500 word target that I have asked for. I had the feeling that you couldn't think of much more to say -- which is generally a sign that there is something about the topic that you don't fully 'get'.

There is a general problem with the 'modular' approach to the BA, in that you will be answering questions, e.g. on Modern Philosophy which would greatly benefit from knowledge of other areas of philosophy, or other philosophers covered in modules which you haven't taken. This particularly applies to the present case, as the issue of 'what it is to grasp a concept' is one of the preoccupations of 20th century philosophy of language, and a key feature of the later philosophy of Wittgenstein.

For similar reasons (as I remarked to another UoL student recently) it helps with the Modern Philosophy module if you have read a bit about Kant, who has deep and very pertinent criticisms to make of Descartes, Locke and Berkeley.

In the 20th century, Locke's account of how we 'abstract' ideas or concepts from experience has come under attack from two directions.

The first questions the coherence of the genetic assumption that we arrive at concepts through a process of abstraction: e.g. a child learns 'red' by being shown different red things, or 'round' by being shown different round things. Peter Geach in his book 'Mental Acts' argues that this gets the order wrong. In the process of learning language, we learn how concepts interconnect at the same time as we learn particular instances of their application. You need to have the concept of 'round' in order to be able to register that a ball, a tomato, the moon are all round. How is that possible? Round is a concept of geometry which we learn concurrently with learning names for other shapes. And where do we get the concept of shape? By being shown different objects with different shapes, and abstracting what they have 'in common'? Evidently not. In other words, Locke represents the process as a linear series of mental actions, when in fact it is more complex and essentially bound up with language acquisition.

The idea that concepts are entities existing in the head, or in particular that concepts are some kind of model or picture or image comes under attack from Wittgenstein in 'Philosophical Investigations' in his account of what it is to follow a rule. Both Platonism (the belief that concepts exist in Plato's World of Forms) and psychologism (the Lockean view) beg the question because applying a model or a picture or an image to the external world itself involves following a rule. We may think it is obvious that a sign with a sharp end 'points' in the direction of the sharp end, but that's just a convention. We learn to 'read' signs that way. There might be a country somewhere where signs are read the opposite way. Suppose you wanted to draw a diagram showing the correct way to read a sign. How do we read the diagram? Again, following a rule is essentially bound up with language knowledge and use.

So in some respects it could be said that in attacking Locke, Berkeley shows himself to be more acutely aware of the problem of explaining how we use and acquire concepts, or how we are able to follow a rule. The notion that a particular idea becomes 'general in its signification' does not, however, look very useful as an alternative account of how we grasp that general signification. The bad explanation is thrown out, but what remains merely seems to beg the question.

You are right that Berkeley's critique seems to acquire greater force if we assume an 'imagist' notion of ideas or concepts. However, psychologism like Platonism isn't wedded to the literal notion of an 'abstract image'. The idea that Plato believed, for example that the Form of Horse IS in some sense a horse (or 'looks' like a horse) came under attack from Plato himself in the '3rd Man' argument in the dialogue 'Parmenides'. In other words, Plato (at least, in his late philosophy) seems to have been fully aware that the notion of Forms as paradigms must not be taken too literally. Even so, Forms or ideas or concepts, be they in Plato's heaven or in your head, are being asked to do to much work if we think that they somehow embody a complete recipe for correct application of a general word.

You mention the main reason why Berkeley 'needed' to attack the theory of abstract ideas, namely, that Locke's doctrine aids and abets the illicit attempt to form a notion of perceptual objects existing unperceived. It is worth noting also that Berkeley uses the same line of argument against Locke's primary/ secondary quality distinction. But, as you say, this is less than compelling as an argument for Berkeley's immaterialism. There might indeed (from Berkeley's perspective) be more than one possible explanation of why we fall into the fallacious belief in the existence of 'matter'.

All the best,


Idealism and our common sense view of the world

To: Siobhan M.
From: Geoffrey Klempner
Subject: Idealism and our common sense view of the world
Date: 23rd March 2010 12:58

Dear Siobhan,

Thank you for your email of 15 March with your fifth essay for the Philosophy of Mind program, in response to the question, 'Can idealism be reconciled with our common sense view of ourselves as agents in a material world? Discuss with relation to either Berkeley's immaterialism or Leibniz's theory of Monads.'

In your discussion of Berkeley and Plato, you have cottoned on to something which is not always made apparent in expositions of Berkeley: that he was strongly influenced by Plato's Theory of Forms.

It is true that Plato viewed the world of Forms as having greater 'reality' than the world of phenomena. For Plato, this means that knowledge is only possible of the Forms (see the Republic and the story of the prisoners in the Cave). Of phenomena such as ordinary tables or horses we can only have opinion or belief.

However, there is a very considerable gap between the Platonic version of 'idealism' and Berkeleian idealism or 'immaterialism', according to which tables and horses are nothing but perceptions, and cannot exist apart from the act of perception. The very notion of matter as a 'something' which occupies 'space' is for Berkeley a meaningless notion.

This isn't scepticism, according to Berkeley, but on the contrary the best response to the sceptic (!). While Descartes in the First Meditation argued that an evil demon might deceive him into thinking that material objects exist when in reality they are merely perceptions produced in his mind, according to Berkeley there is nothing to be sceptical about. What we term 'material objects' are in reality just perceptions and nothing more. God is (in a sense) the 'evil demon'. Or, rather, a benevolent demon.

How exactly is Berkeley's theory like Plato's theory of Forms? As you explain, Plato recognized forms or ideas such as Horse (with a capital 'H'). This doctrine was modified by Medieval philosophers to form the theory you describe, known as 'conceptualism'. According to the conceptualist, ideas are not in Plato's heaven but in your head and mine. But that is decidedly not Plato.

For Plato, as for the conceptualists, the Form of Horse is in some sense a 'paradigm' of what a horse should be. We recognize objects in the phenomenal world which more or less approximate to this paradigm: individual horses.

What Berkeley does is take this notion of 'original and copy' and apply it to each individual object. So the horse we spy in yonder field is a perception in your mind and also a separate perception in my mind. That's two perceptions. But there is only one horse in the field. The 'one horse' is an idea in God's mind. Berkeley used the terms 'ectype' for perceptions/ copies and 'archetype' for the original.

You can attempt to 'do Berkeley without God'. That's what 20th century 'logical positivists' such as Carnap and Ayer tried to do, in giving a 'phenomenalistic reduction' of statements about the external world. According to phenomenalism, every statement about a material object can be analysed as a hypothetical statement, or rather as a set of hypothetical statements, about experiences or possible experiences.

As I said, you can attempt to do it, but in fact the project collapsed: there are sound, logical reasons why it cannot be carried out consistently. You end up chasing your own tail.

Can idealism be reconciled with your view of ourselves as agents in a material world? As you will gather, the question is, 'which idealism?' As you show, there is little difficulty in accepting that I am an agent in a material world and I also have concepts or ideas 'in my head' which I apply to things that I encounter in the material world.

On Berkeley's theory, however, the very notion of physical agency becomes problematic. This is what Dr Johnson attempted to show when he kicked the stone (the real point of this question). Of course, Berkeley can say that he has a perfectly 'good' explanation of what happens when you kick a stone. You form the intention in your mind to move your foot. Then follows a series of perceptions of your foot, the stone, etc. which are just as they would be if in a material world you kicked a stone. Except for the fact that your foot and the stone are in reality archetypes in the mind of God.

If you have ever played a computer game, then you might recognize this as a description of a 'virtual reality'. Sitting in front of your computer monitor, you can 'kick a stone', or hit a golf ball, or drive a sports car just by moving your mouse.

I hope that you can now see the problem. If what I think of as 'the world' is just a virtual reality created by God, then how am I to view my actions in it? Physical agency seems to reduce to purely mental agency. That is decidedly not the view of common sense.

Well done for completing your Pathway!

What to do now? I think that you would enjoy the Ancient Philosophy Pathway which looks at the Presocratic philosophers of Ancient Greece. The University of London Diploma or BA would be possible, but you would need to step up a gear.

All the best,


Plato on recollection and Parmenides on plurality

To: Egor S.
From: Geoffrey Klempner
Subject: Plato on recollection and Parmenides on plurality
Date: 23rd March 2010 12:08

Dear Egor,

Thank you for your email of 15 March, with your one hour timed essay for the University of London Plato and the Presocratics module, in response to the question, 'How successful is the theory of knowledge as recollection in solving the paradox of inquiry?' and your email of 17 March, with your one hour timed essay for the same module, in response to the question, 'Critically assess Parmenides' denial of plurality.'

Theory of knowledge as recollection

This essay at 512 words is on the short side. I would consider 800 words to be the minimum needed to give a good examination answer. Some of my students have managed to write up to 1600 words in response to a one hour timed question.

Your answer is not that bad. You are able to state what the theory of knowledge as recollection and the paradox of inquiry are. However, you would gain more marks by elaborating on those statements.

You also make two valid critical points which I will come to in a minute.

Did Plato mean that the soul, literally, 'sees' the Forms before birth? This ignores the fact that the theory of recollection is intended as a 'myth', a metaphorical expression for the strict and literal truth. What do you think that this literal truth might be? Elsewhere, Plato talks of the soul and the Forms sharing the same nature (Phaedo: the soul is 'akin to the Forms'). This suggests perhaps that the soul, as that which thinks and reasons, shares in the rational structure of reality.

This is not necessarily my view. I'm merely showing an example of how you have the opportunity to show the examiner that you have thought about what the theory of recollection could be.

Again, you state the paradox of inquiry. At face value, the claim that there is a paradox here seems absurd. If I want to know the answer to a question, obviously I don't know the answer but I would know if the answer answered my question if it were put to me. As for the question how one 'goes about finding' an answer, this is different in each case. (E.g. 'How many coins do I have in my pocket?' suggests that I look in my pocket and count the coins that are there. No problem.)

So, we have to consider the paradox of inquiry in the special context of the Socratic method of inquiry. Here it bears a strong resemblance to G.E. Moore's 'paradox of analysis'. You will gain credit for showing that you know what this is.

What does the slave boy experiment show? You are right to be sceptical given the very generous hints that Socrates gives the slave boy. However, some commentators (e.g. Vlastos) have argued that what Plato is really trying to show is that there is such a thing as a priori knowledge. The fact that the slave boy is able eventually to follow the proof shows that he is capable of gaining knowledge a priori, simply through answering questions about some figures drawn in the sand.

You remark that Socrates 'offers no evidence that this method could extend to areas of knowledge other than geometry'. However, it could be argued that philosophical analysis, like geometry, is an a priori form of inquiry and therefore that the experiment with the slave boy does have sufficient relevance.

As it stands, your essay would get a mark in the mid-50s. I would suggest perhaps not relying on headings as you have done, but rather using the standard essay format which I think would prompt you to say more. An essay should be more than just a set of notes.

Parmenides' denial of plurality

This essay is only 394 words, which is very short. You don't really give me much to comment on.

The first thing that an examiner is looking for in an answer to this question is a clear exposition of Parmenides' argument for 'It is'. You talk about the argument in a vague way, but you do not articulate it clearly enough. It is very important to do this -- preferably in numbered steps -- so that you can identify the point where you think that a fallacious inference has occurred.

There has been much discussion by commentators about what 'It' refers to. This has bearing on the validity of the argument. The same applies to 'is'? Is Parmenides using the 'is' of existence or of predication?

To take one example, which bears on your remarks about contemporary physics. Suppose that 'it' refers in some sense to the ultimate reality. Then it is not implausible that, although the world we know is made up of many things, ultimately there can only be one thing. That would be a useful line to pursue, although I would not necessarily agree on that interpretation.

A related interpretation would be that 'It' refers to the One of Milesian cosmology. What Parmenides is arguing, according to this version, is that the Milesians (Thales, Anaximander, Anaximenes) have been inconsistent in allowing their primary substance to form many things.

My own view, for what it is worth, is that 'It' is like 'x' in a logical proof. Take anything you like, any x. 'Is' can mean predication or existence. It makes no difference. Parmenides rejects the idea that we can say that 'it is not' because negation is simply not part of reality.

It is initially plausible to think that if I say that this desk is 'not red' then there is a reality by virtue of which that statement is true, e.g. the desk is brown. Similarly it is 'not square' because it is rectangular. Following this line of reasoning, it would appear that any negative statement ought to be replaceable by a more informative positive claim.

The problem with this line of reasoning is that every predicate that we use has negation built in: 'all determination is negation' is a principle of medieval philosophy. If one attempts to eliminate any form of predication which relies on implicit negation in this sense, then one literally has nothing to say other than 'it is'.

This isn't intended as an indication of what a model answer would look like. There are many possible answers which would be acceptable. I am merely showing the kind of thing you need to do in order to write an acceptable exam answer. In this case, you need to show an awareness that the interpretation of Parmenides' argument is a matter of some dispute, and also be prepared to do some philosophy, in working out possible interpretations, arguments and counter-arguments.

As it stands, your essay would score in the low-50s.

All the best,


Tuesday, June 11, 2013

Heraclitus on the unity of opposites

To: Ruy R.
From: Geoffrey Klempner
Subject: Heraclitus on the unity of opposites
Date: 19th March 2010 13:09

Dear Ruy,

Thank you for your email of 13 March, with your essay for the University of London Plato and the Presocratics module, in response to the two questions, 'In what sense or senses does Heraclitus believe in the 'unity of opposites'?' and 'How should we understand Heraclitus' claim that opposites are one? Does this claim commit him to inconsistency?'

First of all, in your email you expressed the worry that 'time is not on my side'. My advice to you would be to not panic.

It is very important at this stage that you carefully review the parts of the syllabus which you have covered, in relation to the usual (and to a considerable extent predictable) spread of examination questions. Which kinds of question, or what topics, would be your first choice? or your second choice? Don't lose what you already have -- your understanding of the topics you have covered in attempting to cover new ground.

Your answer to the two questions is good so far as it goes, but it doesn't really tackle the issue of logical consistency. What you do, is offer thoughts on the nature of the Logos, which would be an answer to a different question, such as, 'What does Heraclitus mean by the Logos?'

A good answer to either of the two questions about the unity of opposites would review the different kinds of 'unity of opposites' that Heraclitus refers to in the fragments, with an example of each. What is the principle illustrated behind each example, or set of examples? I can't write this essay for you, but you will find it in my notes, and also in a text book on the Presocratics. There are at least three distinct kinds of example.

Having analysed the different ways in which for Heraclitus opposites form a 'unity' the next task is to decide whether he is in fact falling into inconsistency (or, in some versions of this question, 'denying the law of non-contradiction'). To say that A is 'the same' as not-A in the sense in which this entails a logical contradiction, Heraclitus would have to be committed to holding that A and not-A are the same in the same respect, at the same time, and from the same point of view. The standard defence of Heraclitus would be that he never says this. There is always a change in time, or respect, or point of view.

That would earn you a mark in the mid-60s. However, you could go on to consider whether that defence of Heraclitus is just a little bit too 'easy', and whether, in fact Heraclitus did in fact intend to make a stronger claim, to the effect that the world somehow defies ordinary human logic (as hinted in your second paragraph) so that any attempt to describe reality in its fundamental aspect in some sense requires that we make contradictory statements.

With regard to the traditional interpretation of Heraclitus, as a defender of the traditional view I would argue that Heraclitus is not well served by his student Cratylus, or Plato for that matter. We need to distinguish levels when talking about the world or reality. There is the mundane level, where we identify objects or entities such as 'a river', 'a tree', 'a chair', 'a man', and the metaphysical level which exhibits the true nature of reality which cannot be approached using ordinary descriptive language. Hence the need to resort to metaphors and images.

The examples of a fire, or a river, are images for what exists at the fundamental level -- a constant process of change. A philosopher I mention in the unit on Heraclitus is Whitehead, who evidently saw his theory of process as in some sense vindicating Heraclitus' view.

For Whitehead, reality is composed of events at the fundamental level. This gives rise to the world of 'objects' that we know and describe in language. The Logos fulfils the same function as is served by the eternal Forms in Plato's two world theory.

Whitehead in fact claimed that all Western philosophy is 'merely footnotes to Plato'. Whitehead's process philosophy is Platonic insofar as the world we know arises out of two elements, the flow of events and the universals which give rise to repeatable patterns which we discern in language.

All the best,


In what sense is Hume a sceptic about causation?

To: Mark S.
From: Geoffrey Klempner
Subject: In what sense is Hume a sceptic about causation?
Date: 19th March 2010 12:37

Dear Mark,

Thank you for your email of 14 March, with your essay for the University of London BA Modern Philosophy: Descartes et. al. module, in response to the question, 'In what sense, if any, was Hume a sceptic about causation?'

This is an excellent answer to the question. I liked our observations concerning the various 'mitigating factors' regarding scepticism: naturalised epistemology, pragmatism, contextualism etc.

I agree that Hume is, in your terms a 'mitigated' sceptic about the truth of causal determinism, and also about individual claims that c is the cause of e, and an 'unmitigated' sceptic about the notion of a 'necessary connection' between cause and effect.

However, I do have problems with Hume's use of the term 'sceptical'. Though it may have corresponded to the usage of the day, his attacks on metaphysical claims would not be described as 'scepticism' according to modern usage. If I claim that the notion of X is incoherent, I am not being 'sceptical' about the existence of X: I am simply denying it. You can be sceptical about the existence of God (given that there is more than one possible definition of God) but if you regard the notion of time travel as involving a logical contradiction, then you are not a sceptic about time travel, except in a loose sense, as 'one who denies the logical coherence of time travel'.

I may have expressed before my view that the notion of the truth of a statement of 'constant conjunction' -- the truth of an unrestricted universal generalization -- is itself something that an opponent of metaphysics could well have doubts about. However, to my recollection, nowhere in the Enquiry or Treatise does Hume consider this from the point of view of what would now be called 'realism' or 'anti-realism' about the truth or meaning of universal generalizations. If this is the cure, how much worse must be the disease? Yet, for Hume, the idea that there exists, in reality, an unperceived and unperceivable link between cause and effect apart from what we can observe is indefensible. It is we who supply that link, in 'spreading our minds' over objects.

It is surprising, therefore, that in his 'unmitigated scepticism' with regard to necessary connection, the thought of what exactly it would mean to assert or believe the 'truth' of an unrestricted universal generalization never seems to have occurred to Hume. One possible explanation is that Hume is so thoroughly entrenched in an anti-realist mindset that he doesn't even see the need to make the case.

Saul Kripke in his book 'Wittgenstein on Rules and Private Language' compares Wittgenstein's account of following a rule to Hume's critique of the notion of causation as a 'sceptical solution to a sceptical paradox'. As with last time, this isn't something you would necessarily know about, but I would bet that the allusion was in the examiner's mind when the question was composed. That would be something worth following up.

One thing you could also have done is compare other kinds of thing that Hume expresses unmitigated scepticism about: the self as an entity, the 'continued and distinct' existence of the objects of perception. How do these compare with his scepticism with regard to necessary connection? For starters, Hume is so dismayed by his conclusions regarding external objects, that the only solution seems to be to go off and play his game of backgammon. He doesn't at all like the conclusion he is driven to, yet he insists on it because it follows from his own principles concerning ideas and impressions.

In the case of the self, Hume is more inclined to see this as an illusion which we can dispense with. There will still be David Hume, the physical person (modulo the problem of external objects) and his mental states. No need for an additional internal 'owner' of those mental states.

Again, with necessary connection, Hume seems to think that we are much better off without this piece of metaphysical baggage.

What Hume does offer, in a kind of 'mitigation' of this unmitigated scepticism is his theory of fictions. You remark about his projectionism, the idea of the mind 'spreading itself' on objects. It is the same process of composing fictions which accounts for our notion of the distinct and continued existence of external objects, and, possibly also the self (although I'd have to search hard to find a reference for this).

In this regard, Hume is seen by commentators as having anticipated to some extent Kant's treatment of causation, external objects and the self. What were for Hume, 'necessary fictions' become for Kant 'synthetic a priori principles of the understanding'. Again, something that you will be able to follow up when you commence your studies of Kant.

All the best,


Plato on happiness and justice

To: Scott B.
From: Geoffrey Klempner
Subject: Plato on happiness and justice
Date: 19th March 2010 12:37

Dear Scott,

Thank you for your email of 11 March with your essay for the University of London BA Plato and the Presocratics module, in answer to the question, 'Is Plato justified in thinking that the just person is happier than the unjust person?'

Your essay consists mostly of an exposition of Plato's views about the tripartite nature of the soul, and the difference between an ordered and disordered soul, and how this corresponds to Plato's understanding of justice and injustice. However, you seem to go over the same ground not once but several times, as if you were trying to convince yourself that Plato is justified in thinking that the just person is happier than the unjust person.

The exposition is clear, so far as it goes, and shows that you have a good understanding of how Plato conceived of the soul and its internal structure. However, by the end of the essay, you haven't answered the question at all. You have merely repeated Plato's claims.

You do, however, pose the one question that needs to be asked in order to give an effective answer: Does Plato succeed or fail in making the connection between what Sachs calls 'Platonic justice' and 'vulgar justice', or what would normally (prior to any particular theory of justice) be understood as just or unjust?

Well, does he? You don't offer an opinion. You merely repeat Plato's claim that a person who acts unjustly (in the ordinary sense) must have a disordered soul. You couldn't have an ordered soul in Plato's sense and commit an unjust act. That's a pretty strong claim that takes some arguing.

The question isn't specifically about Plato's analogy between the individual and the state. However, one question you could have asked is whether it is possible, in Plato's terms, for a just man to live in an unjust state. Socrates claimed that it was 'better to be wronged by others than to do wrong to others'. However, it is not at all easy to see in Plato's terms how one maintains the internal order of one's soul when there is chaos without. Surely, we can conceive of circumstances where ruthless action, ignoring questions of justice, would be unavoidable.

Can a just man in an unjust state be happy? Plato is committed to holding that the just person is happier than the unjust person in every possible circumstance, not just in favourable circumstances. The latter wouldn't be a very interesting claim.

One way to pose Sachs' question would be to try to imagine a Ring of Gyges scenario -- a man who exploits his position to do unjust acts with complete impunity -- yet who apparently has all the Platonic virtues: he exercises rational forethought and self control; he is courageous in not deviating from his plan regardless of setbacks; he is moderate in his appetites. In other words, the Perfect Villain.

So we can now pose the original question in terms of this thought experiment: Does Plato succeed in proving that there could not be such a person as the Perfect Villain?

This connects with a claim you make near the beginning of your essay, which seems patently false: 'According to the Sophists, being unjust is more advantageous as by deceiving others and disguising oneself as just, the unjust person can live a comfortable and pleasant life.' I recognize this as an allusion to the Ring of Gyges scenario: but which Sophist made this claim? I suspect that you are mixing things up here.

Thrasymachus, who was a famous Sophist of the day, asserts in the Republic that 'justice is the interest of the stronger'. That is not the same thing as saying that injustice is more advantageous than justice. What Thrasymachus means is that justice is defined in relation to the ruling power, and its interests. The state creates the laws, which are designed for the benefit of the state. That is justice. It is just that conquered peoples should be enslaved. Any war which serves the interests of the state is a just war by definition.

Is this a legitimate view? If not, why not? One could imagine a group or tribe of Perfect Villains (who treat one another with fairness honour, as befits respect for one's equals) who do not regard any action taken against members of the enslaved class as 'unjust'. You might recognize this as a caricature -- or perhaps not such a caricature -- of Nietzsche's views concerning the Ubermensch.

Why can't you be a perfect villain, or an ubermensch (I'm not necessarily saying these are the same thing) and be blissfully happy? Why can't you be blissfully happy as a Samurai slaughtering peasants? What's wrong with that? Isn't a Samurai warrior someone to be admired?

I think that the answer to this question lies in a remark I made earlier, 'he is courageous in not deviating from his plan regardless of setbacks'. What plan? Surely not Gorgias' claim (in the dialogue of the same name) that the best life is one where one has 'as many enjoyments as possible'. How about friendship? Honour amongst one's peers? Isn't there something missing from this picture, a sense of responsibility for those whose lives are in your power? Plato would say that. But why? Why is that necessary for happiness?

All the best,


Paradox of the heap for non-philosophers

To: Ian C.
From: Geoffrey Klempner
Subject: Paradox of the heap for non-philosophers
Date: 18th March 2010 12:20

Dear Ian,

Thank you for your email of 7 March, with your first essay for the Philosophy of Language program, in response to the question, 'How would you explain to a non-philosopher the philosophical significance of the paradox of the Heap?"

In your essay, you make the case for the utility of vague terms in ordinary English. As you point out, the vague terms that we use, like 'heap', are sufficient for the purposes for which we use them, and when greater precision is needed, we use more precise, or specialized vocabulary.

In making this point, it is important to distinguish between cases where it really doesn't matter what word you used, and cases where a person understands what you said, in the same sense as you intended to say it. If we are driving a noisy truck and I shout to you, 'Be careful there's a --- of sand just around the next corner', I succeed in getting the information across even though you didn't actually hear the word '---'. You surmised, correctly, given the context, that whatever a --- of sand is, it is something to avoid. That's not generally a good model for the way vague predicates work.

You could also have gone on to consider possible definitions, e.g. of a heap, and why they would be of no use. Imagine a council bye-law prohibiting the depositing of heaps of sand, which includes a definition of a heap of sand as one which has such-and-such minimum circumference and height. This definition of a 'heap', if applied to everyday usage, would make a statement like, 'I noticed a heap of sand in your drive' dependent for its truth on certain precise measurements being taken. Moreover, we would need separate definitions for 'heap of books', 'heap of clothing' etc.

A non-philosopher would have no difficulty in agreeing to all of this.

However, the conclusion a reader might come to is that there doesn't seem to be a paradox here, let alone any observation of any philosophical significance. That's two things you need to explain.

Why is there a paradox?

I take it that you admit the validity of logic, and the principle of mathematical induction. Severe consequences follow for human knowledge if we don't accept this.

However, to take your example, it follows from the statement,

1. One grain of sand cannot make a heap


2. If you add one grain of sand to a collection of m grains of sand which cannot make a heap, then the resulting collection of m+1 grains cannot be a heap


3. For all n, a collection of n grains of sand cannot make a heap.

This is a paradox. A paradox is an apparently sound argument which leads to an impossible or contradictory conclusion. There are paradoxes whose philosophical significance would be quite difficult to explain to a non-philosopher, e.g. Russell's paradox. Is this one of those paradoxes?

It is uncontroversial (as you have argued) that many of the terms we use in ordinary language are vague. However, I think that it is more controversial that when we are using ordinary language, we have to abandon logic. Of course, not everyone has an appreciation of what logic is, and why we need it. But I take it that you don't need to be a philosopher in order to appreciate the importance of logic.

This is a non-unfamiliar situation in philosophy. We encounter a problem or a paradox whose solution requires that we give something up, that we reject an assumption which we previously held, not realizing that the assumption in question was problematic.

We need logic. And yet we have to recognize that we can't always use logic. The laws of logic as such have no exceptions. But the application of those laws to the everyday world, paradoxically, does have exceptions. Ordinary language isn't built for logic. It's built for negotiating our way around the world (in order to avoid heaps, or find things in heaps etc.)

The philosophical significance of this observation is that we have to revise what seems at first a very plausible view of the nature of linguistic usage, namely, that words are learned, and used, according to rules. 'Logic' and 'rules' are correlative notions. You either obey the rule or disobey it. An inference is either logically valid or logically invalid. There is no third alternative.

But if words are *not* used according to rules in this sense, then how on earth do we manage to talk coherently? How do words work? What is meaning?

From the fact that we successfully communicate, and collaborate in our activities, that whatever it is that keeps the use of language 'on track' is doing so pretty effectively. As a philosopher, that is something to investigate. A plausible theory or model of the meaning of 'meaning' doesn't work. Hence the challenge for the philosophy of language.

All the best,


Friday, June 7, 2013

Goodman's new riddle of induction

To: Chris M.
From: Geoffrey Klempner
Subject: Goodman's new riddle of induction
Date: 12th March 2010 14:00

Dear Christian,

Thank you for your email of 7 March, with your essay for the University of London BA Logic module, in response to the question, 'Is there a satisfactory solution to Goodman's new riddle of induction? If there is, what is it? If there is not, what are the consequences?

This is a very good answer to the question. You have successfully got to grips with the main issues around Goodman's paradox, in particular the idea of 'kinking' (as you describe it,) and the implication that the kinking would have to go 'all the way down' in order for the putative symmetry between normal predicates and grue-like predicates to hold. As you observe, you would need a story about powers and supervenience of phenomenal qualities on underlying structure etc. etc.

The point to make about disjunctive predicates generally, is that you are still relying on a given language in order to define the kinked version. So we have to take a step further and imagine an untranslatable language (Davidson questions this in 'On the Very Idea of a Conceptual Scheme', but all he shows is that nothing could count as 'discovering' the existence of such a language).

Let's keep the discussion on the level of human and alien science. Because, as hypothesised, the kinking goes 'all the way down', there can be no communication between humans and aliens. Our conceptual schemes are too radically different.

However, there is one aspect which one needs to take into consideration, which is how the world 'really is'.

Consider first the original problem of induction. Why should the future resemble the past? Are justified in believing this on inductive grounds? or deductively? or are we just guessing and hoping?

Descartes, in effect, posed this question before Hume with his hypothesis of an evil demon. Leave aside the radical possibility that there is no spatial world at all (just me and the evil demon). The evil demon can make the world any way he likes. If he is good (i.e. godlike) he would make a world in which the responsible use of inductive argument is more likely to result in true beliefs. If he is bad, then the world *looks* like a world in which the responsible use of inductive argument is more likely to result in true beliefs, but in reality is cleverly designed so that we will end up believing all sorts of fantastical things, on 'good' inductive grounds, which aren't in fact the case.

Now, let's look at the same question from the point of view of Quine's 'naturalized epistemology'. There is no a priori proof of a benevolent god, or that the universe is fit for science (as we understand it). All we have is our capacity for empirical research, which, as it happens, thanks to Darwin can provide a very good explanation of how human beings have evolved with dispositions appropriate for noticing relevant properties and projecting them.

However, a priori, you still can't rule out the evil demon or evil scientist hypothesis. Let's say the evil demon has created the human race and also the alien race, and given the aliens the innate ability to project the properties which really correspond to the 'kinked' way the universe has been created, while human beings are blissfully unaware that inductive practices which they find natural and reasonable are leading them further and further away from a true picture of this warped universe, or mini-universe.

As an empirical theory, the 'new' evil demon is a non-starter. There is absolutely no reason to believe it. But that's precisely the point: the game of science is about looking for the best explanation (as we've already discussed). Only philosophers concern themselves with crazy, science fiction hypotheses which have no bearing on the way science is actually practised.

I haven't said anything here with which Goodman would disagree. We can't justify our inductive practice because (short of proof of the non-existence of an evil demon) all we have to go on in determining how the world is, is our inductive practice. We do what we do. The predicates we project are the ones which are projectible. That is all rationality amounts to. There is 'no first philosophy' (Quine), no higher court of appeal.

I'm not sure how to best describe that conclusion in terms of the alternative offered by the exam question of a 'satisfactory solution' or 'no satisfactory solution'. To talk about solution implies a problem, something we have to do something about (as, e.g. quantum mechanics poses a problem for the traditional view of causality). I don't think we have to 'do' anything about it. It's an intriguing puzzle, a 'riddle', as Goodman says, but one which nevertheless shows something profound about the nature of reality, and the limits of human knowledge.

All the best,


Does 'is true' specify a genuine property?

To: Bogdan P.
From: Geoffrey Klempner
Subject: Does 'is true' specify a genuine property?
Date: 12th March 2010 12:46

Dear Bogdan,

Thank you for your email of 6 March with your essay for the University of London BA Logic module, in response to the question, 'Does the predicate 'is true' specify a genuine property of assertions?'

I agree with you that this is a difficult topic, but you seem to have a good handle on it. I think possibly that your investigation has been handicapped to some extent by your assumption that a deflationist theory of truth somehow downgrades the importance of truth, or has the implication, as you put it, that 'the truth predicate has a very limited role to play in communication'. Yet you start your essay with a statement with which anyone would agree: 'The notion of truth plays a major role in our lives and is fundamental to communication and scientific investigation'!

No wonder you feel a bit confused.

You cover many of the points that need to be made in an answer to this question. For a start, we may ask what it means to say that 'is true' does or does not 'specify a genuine property'. You go about answering this in the right way, by looking at other predicates which do specify genuine properties. For example, 'is intelligible'. If I say that John's assertion was intelligible, you who do not find it intelligible can ask me to justify my claim, and I will do so by explaining what John said. After I have given my explanation, you do find the statement intelligible. Other statements, though they pass tests for grammaticality (i.e. being formally acceptable), are really not intelligible. There is no possibility of giving an explanation in this case, because there is nothing to explain. There is surely a strong case for saying that intelligibility is a property which an assertion can have, or lack, even though there may be many cases (as with other properties) where there is room for dispute.

It doesn't follow from this that intelligibility is something that can be defined, other than in a piecemeal way. However, the question was about ‘being a genuine property’ not about definability.

It is useful to think of some other examples: 'John's assertion was combative', 'John's assertion was candid', 'John's assertion was poetic'.

Why isn't truth like this? Consider an example. Suppose I say, 'Theories of truth have an innate tendency to supervene on theories of perception.' I just made this up, as an example of a statement which is unintelligible, although this is not something that just anyone would see immediately. For a start, I don't know what it means for a theory to 'supervene' on another theory, or how a theory can have a 'innate tendency'. By contrast, if you ask me what it is for this statement to be true, then I don't have to say anything more than, 'Theories of truth have an innate tendency to supervene on theories of perception' is true if and only if theories of truth have an innate tendency to supervene on theories of perception.

One way of explaining the ambitions of non-minimalist theories of truth (correspondence, which you mention, but also coherence and pragmatic) is that they attempt to give an explanation which is analogous to the explanation we gave of intelligibility. In the example above (which I won't repeat again) you tell some story about words, the world, the actions of human beings etc. etc. and the upshot of this story is an explanation which somehow accounts for the attribution of the truth predicate.

Theorists of truth are quick to point out that a statement of what truth is, or what truth consists in, is not the same as a criterion of truth. Knowing what is the true theory of truth doesn't give you any additional means of verifying an assertion which you didn't have before. What it does give is an understanding of what you are saying when you state that an assertion is true.

I am fully with Davidson on this. If you understand the statement then you know what it is for it to be true, because that's just what understanding is. There is nothing more to say. If you do try to say something more, you are risking an infinite regress. Frege made substantially the same point in his essay, 'The Thought: a Logical Inquiry' where he expressly argues for the indefinability of truth on the grounds that we would need to ask, of any putative definition, whether it is 'true'.

However, having got this far, I don't think that it necessarily follows that philosophers have 'nothing further to say' about truth. On the contrary, there are real, substantive issues about truth, such as the question of realism vs. anti-realism about truth (see Dummett 'Reality of the Past'), or the question whether ethical assertions, which formally can be described as 'true' of false (because they pass the grammatical test) are capable of being true, and, if so, how do we account for the difference between ethical and non-ethical assertions without falling back on a more full blooded account (e.g. as a correspondence theorist would say, 'Ethical assertions do not correspond or fail to correspond with facts').

For this reason, I find it intelligible to say that while truth is not a genuine property and is not definable, nevertheless there is scope for a non-trivial theory *about* truth.

All the best,