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Essays on Descartes and Heraclitus


To: Pearl K.
From: Geoffrey Klempner
Subject: Essays on Descartes and Heraclitus
Date: 3 January 2006 10:47

Dear Pearl,

I am finally back at my desk after a longer than normal Christmas/ new year break. Thanks for being so patient!

Thank you for your email of 16 December with your essay for the University of London Introduction to Philosophy module, 'Descartes' Method of Doubt', your email of 24 December with your essay for the Presocratics and Plato module, 'Heraclitus', and your email of 30 December with your second Introduction to Philosophy essay, 'Cartesian Dualism'.

Before I start, you should be thinking about how you would answer specific questions rather than writing essays on general topics (like 'Heraclitus' or 'Cartesian Dualism'). Much of the skill in writing a philosophy essay consists in constructing a case which effectively answers the question, avoiding any points which are irrelevant to the question.

This is why it is a good idea to chose questions from past examination papers. Examiners very rarely ask you to 'say all you know about topic X', in fact they never do. There will always be a little twist, a different way of phrasing the question which catches you off guard, or an ambiguity which needs to be brought out. This is one of the most important factors in scoring high marks.

I accept that there is a certain degree of conflict with your need to cover the topic. However, one way to do this would be to write essay-style notes on the general topic at the same time as you compose your essay in response to a specific question.

OK, mini-lecture over. Let's look at the essays.

Descartes' Method of Doubt

One thing I liked straight away is that you set yourself a specific goal: to 'argue that the Method of Doubt... is in fact detrimental to the attainment of knowledge'.

This makes my task easier. I have to ask whether you have, in fact, successfully made out your case.

The first point you make is that 'It can be inferred from the First Meditation that Descartes believed true knowledge is based on beliefs that cannot be doubted.' Then you ask, 'Need a belief be absolutely beyond doubt before we can accept it as knowledge?' and give the example of Copernicus' Theory which is or might be regarded as 'knowledge' despite the fact that some doubt it.

The problem here is that you are conflating two different claims. A case needs to be made that the first claim entails the second. The first claim is that knowledge rests on indubitable foundations. The second claim is that any belief that we regard as knowledge must be indubitable. However, there is room for a theory which holds that the foundations of knowledge are indubitable while the superstructure of beliefs based on this foundation is not. For example, a sense datum theorist might argue that I know for certain that I see a patch of red, but that knowledge of the external world is always subject to a degree of uncertainty.

Later in the Meditations, Descartes goes to some length to explain why, even though God is not a deceiver, human beings make false judgements based on experience.

Moving on to Descartes three arguments, you correctly describe the 'structure and strategy' of the three arguments, despite giving the initial false impression that the Sensory Deception argument was meant to stand independently. However, this is just careless drafting. As Descartes notes, we rely on evidence gained from perception in differentiating veridical perceptions from false ones.

On the Dreaming argument, you suggest that dreams and reality can be distinguished 'because the level of self-consciousness and sensory ability is different'. However, this is a relatively superficial point which is effectively defeated by the Matrix scenario. Our dreams could be much more lifelike than they in fact are.

On the Matrix, there is a crucial difference which needs to be brought out, namely, that the backdrop to the Matrix scenario is a material world in space, whereas the Evil Demon scenario raises the possibility that there is no 'matter' or 'space'. Kant is relevant at this point, because he effectively concedes that we live in a world were space and matter are mere 'appearances' caused by an unknowable noumenal reality (rather than by an evil demon).

Your best argument against Descartes (and the one that convinces me) is that pursuing the Evil Demon possibility to its limit, we cannot count on the ability to think rationally, because this too could be controlled by the Evil Demon. This will later become relevant if you tackle the topic of the infamous 'Cartesian circle'.

I am not sure that your references to Kant really helped your argument. I have indicated one place where Kant's philosophy is relevant (the phenomena/ noumena distinction). In criticizing Descartes' method of doubt, you would really need to talk about Kant's attack, in the 'Refutation of Idealism' on the Cartesian idea of subjective 'knowledge' which is logically disconnected from knowledge of an external world of objects in space.


This time you propose to cover the logos, the doctrine of flux, the unity of opposites, the role of fire in the cosmos and how the logos applies to human life - in other words, a synopsis of Heraclitus' philosophy. Let's see how well you do.

This time, I am going to comment as I read.

'There is one universe' is not a sufficient explanation of 'all things are one'. Even if the universe was just a pile of rocks it would be ONE pile of rocks. What additional factor do you think that Heraclitus had in mind? what is unity?

You go on to explain why the 'logos needs opposing forces in order to function'. The obvious question to ask is how does this help in creating a stronger, more effective kind of unity? Here is one possible explanation. If A cannot exist without B and B cannot exist without A then a universe consisting in A plus B would in some sense have a greater 'degree of unity' than a universe which just happened to have an A and a B.

You go on to describe the doctrine that 'everything is in a state of flux'. Here you miss an opportunity to point out that the Logos plays the same role, in relation to the world of constant flux as Plato's theory of Forms. The Logos is the constant law governing all changes. The philosopher's knowledge is, effectively, knowledge of the nature of the Logos (of which most men prove uncomprehending). However, it must be conceded that Plato's Theory of Forms does give a more satisfying account of the objects of philosophical knowledge.

Then you give a brief overview of the unity of opposites - an essay topic in itself. A typical exam question would be, 'In asserting the unity of opposites is Heraclitus guilty of self-contradiction?' In your answer, you would need to explain what would suffice to show that Heraclitus had asserted a self-contradiction then explain how the various kinds of example can be explained in a non-contradictory way.

I like the explanation of why Heraclitus does not need a cosmology. I am less sure of your speculation that Heraclitus was influenced by the myth of the Phoenix. There is no evidence that Heraclitus believed that the universe as a whole went through cycles where the everlasting fire is kindled and extinguished. Rather, the kindling and extinguishing is happening everywhere, all the time. As one fire dies down, another blazes up. This fits in more comfortably with other things Heraclitus says, although admittedly there is no logical reason why (as with Empedocles) there could not be an everlasting cyclic process of change between two extremes.

One question raised by the identification of fire as the 'arche' is what difference it makes to say that 'air is really fire' (Heraclitus) rather than 'fire is really air' (Anaximenes) or 'fire is really water' (Thales?). Point to a glass of water and say, 'That is really fire'. What does that mean? what point are you making?

My main criticism of this essay is simply that you were not answering a specific question. But you have done well in covering a lot of material.

Cartesian Dualism

Again, the essay suffered from a lack of focus. There are a number of different questions which could be asked here.

How do you evaluate the argument that Descartes gives for the view that he is essentially a non-material, thinking thing existing in relation to a material non-thinking thing? For example, consider the argument, 'It is possible to be certain of the existence of X while doubting the existence of Y, therefore X cannot be Y.' How good is that argument in general? Can you think of counter-examples?

Another question concerns the coherence of mind-body dualism. A point that you might not be aware of is that there is a significant difference between Cartesian physics and Newtonian physics which allows the 'loophole' of the pineal gland explanation. In Cartesian physics momentum is conserved, rather than energy, so it would be possible to 'change the direction of the animal spirits' without applying physical force.

You describe Strawson's objections to the notion of a non-physical thinking substance but you don't give the arguments. Actually, the arguments go back to Kant, who hypothesized (for the sake of reductio) a succession of momentary 'soul substances' each of which passes on its states to the next like a line of colliding billiard balls. Strawson considers a parallel scenario, where the person, e.g. writing these words to you is not one soul substance but a thousand soul substances, each thinking identical thoughts. The point is not that 'we will never know' how many souls we have or whether our souls have an identity over time, but rather that the very distinction between 'identity' and 'difference' becomes meaningless in the absence of a 'criterion of identity'. That is Strawson's case.

In your last paragraph, you give some arguments which are intended to show that 'mental and physical activities are too complex to be reduced to any of these theories' (sc. cartesian dualism, materialism, idealism). It is not at all clear from your examples why a dualist, materialist or idealist could not happily give their explanation of what it is to play a video game, walk into a room or remain absolutely motionless. The first requirement of any philosophical theory is that it should be consistent with everyday observation, even if this means rejecting the naive beliefs which we hold about the real nature of our experiences.

- You have made a good start. The view I expressed at the beginning (prior to reading your essays) has been vindicated, to the extent that the best of the three was the first because it was the most focused. So my advice is in future pick exam questions and make sure you stick to the question and don't wander off the point.

Well done!

All the best,


P.S. A point I missed: There is an issue about whether knowledge implies certainty which I failed to address in my comments. There is strong evidence that Descartes did hold this. However, my point still stands that this view of knowledge is not entailed by the claim that knowledge (however defined) requires indubitable foundations.