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Essays on Descartes and Locke


To: Stuart B.
From: Geoffrey Klempner
Subject: Essays on Descartes and Locke
Date: 25th November 2008 12:05

Dear Stuart,

Thank you for:

- your email of 21 October, with your University of London Modern Philosophy essay in response to the question, 'Does Descartes reason in a circle when he argues that everything we clearly and distinctly perceive is true because God exists and is not a deceiver?'

- your email of 13 November, responding to the question, ''That with which the consciousness of this present thinking thing can join itself, makes the same person, and is one self with it, and with nothing else' (Locke). What are the strengths and weaknesses of this account of self?'

- your second email of 13 November responding to the question, 'Locke claims that ideas of primary qualities resemble the qualities themselves, while ideas of secondary qualities do not. What does he mean by this? Does he succeed in establishing it?'

- your email of 21 November, responding to the question, 'Different Men... have different Essences of Gold, which must therefore be of their own, and not of Nature's making' (Essay What did Locke mean by this? Does it imply that the classifications that we make of things in the world are arbitrary?'

Cartesian Circle

In an examination, you wouldn't have time to go into such detail over the argument from formal reality/ objective reality etc. etc. Nor do I think that a discussion of the (alleged) Cartesian circle requires this.

The main issue here is your contention that Descartes distinguishes between 'clear and distinct ideas' as such, and truths arrived at by the 'natural light' or the 'light of reason'. It is somewhat puzzling, therefore, that you do not give a single example of a proposition which arises from a 'clear and distinct idea' which is not validated by the 'light of reason'.

I don't think Descartes intends to draw the distinction which you allege here. If he did, he would have said much more than he actually says. However, there is a semantic distinction that one might draw between conceiving of an idea and assenting to a proposition, although for Descartes this line is somewhat blurred. My idea of substance as such is a clear and distinct idea, from which a number of propositions follow. For example, the proposition that a mode cannot exist in the absence of a substance in which it inheres. This proposition is validated by the 'light of reason'. In short, 'clear and distinct' relates (more) to perception while 'light of reason' relates (more) to judgement.

There is another question which you point to about rational judgements of probability. These are possible because God is not a deceiver. We can base reasonable judgements on the evidence of our senses, even though our senses do sometimes deceive us (Descartes goes to considerable lengths in Meditation 6 to explain how this happens). In other words, there is a distinction between judgements which we know to be true by reason, and judgements which we know to be true because they are rationally inferred from strong evidence as the 'best explanation' of our experience.

What, then, about the Cartesian circle? In Meditation 1, we have seen that Descartes dismisses without argument the possibility that he is a 'madman'. In other words, it is axiomatic that he has the capacity to reason. Even so, one can be deceived about things which are based on rational argument. The longer the chain of reasoning, the easier it is to slip up. The evil demon has the power to make me get my sums wrong even if he can't make me think that 2+3=6. Here is a good example of how 'clear and distinct' ideas trump 'truths by the light of reason'. You can just *see* that 2+3=5. You can't just 'see' that 123456 to the power of 3 is (whatever it is), even though each step in the calculation is show to be valid by the light of reason.

Descartes can't go wrong, he thinks, provided that he takes very short steps in his reasoning. 'I exist' is a given. Each further step must meet the standard set by the cogito. Once God's existence is established, then he can trust longer chains of reasoning, as well as the evidence of his senses and his sense of 'best explanation'.

Locke's account of self

I don't think you meant to say that, literally, an object A is one and the same as object B if and only if there is 'no addition or subtraction from the collection' of atoms. This clashes with what you say in a previous paragraph, that it is our idea of the kind object in question that determines how we regard its identity. For example a 'house' is the same house even if it gets repaired over time and has rooms added on.

This view is consistent with David Wiggins' account of identity as 'spatio-temporal continuity' under a 'covering sortal concept' (see his book 'Sameness and Substance' Blackwell).

Once again, in an exam, you only have limited time to discuss Locke's account of the identity of inorganic objects or organisms.

One surprising omission, however, is the thought experiment of the prince and the pauper soul swap, designed to prove that personal identity has nothing to do with 'identity of substance' (i.e. Cartesian soul substance). This is crucial to Locke's 'forensic' criterion of sameness of consciousness. (Locke indeed stresses that personal identity is a forensic notion.)

You have missed two vital criticisms. The first criticism arises from the questionable status of memory claims. In Locke's account, the continuity of consciousness is an entirely separate matter from the continuity of the biological organism in which the consciousness 'resides'. The result is that Locke has no means of distinguishing 'veridical' from 'false' memories. Whereas, in an account which recognizes that memory necessarily is embodied, involving physical causation, we have the means to distinguish a memory which arises from the 'right kind' of causal chain and one that does not. (You will find this in Wiggins.)

The second criticism relates either to consciousness with memory, or to the account you offer at the end, which attempts to avoid memory altogether by focusing on the immediate continuity of consciousness from one moment to the next. Let's say an evil scientist (or evil angel) puts me in a duplicating machine which instantaneously creates two GKs. Each GK copy has a consciousness which connects to the consciousness of the GK who entered the machine. In other words, there is no way that by focusing on the subjective quality of consciousness one can establish identity over rival claims. (Sydney Shoemaker in his book 'Self-Knowledge and Self-Identity' was the first philosopher to consider this kind of case, in his thought experiment of brain splitting and transplantation.)

This is of course not just a problem for Locke but for accounts of personal identity generally, although arguably it is worse for Locke because body has no essential part to play.

Locke on primary and secondary qualities

This is a good essay so far as it goes. You have given a good explanation of what Locke means by his claim that primary qualities 'resemble' the qualities themselves while secondary do not. The second question, however, is whether he 'succeeds in establishing' this claim.

It won't do to say merely that Locke was concerned to 'provide a sound philosophical foundation for the corpuscular hypothesis', even though, this is most likely true. The distinction in question, and the claims based upon it, is intended to be a priori, based purely on reasoning on the basis of the nature of primary and secondary qualities as defined. It cannot be acceptable (I'm not saying you think it is) that the 'correct' philosophical theory is contingent on whether a given physical hypothesis, such as corpuscularianism, is true.

We know that corpuscularianism is false. There are atoms, to be sure, but they are not the bedrock of physical theory. On the contrary, the basic concepts of particle physics are theoretical constructs which bear only a tangential relation to human experience.

This makes a difference. However, the question is how much of a difference. Can't we still say, that the snowball appears round because it 'is' round? How do you define 'round'? by Euclidean geometry? But what if space is not Euclidean?

It could be said that Locke's picture of the nature of physical hypothesizing is fundamentally flawed because he sees it as merely a substitute for direct perception (at one point he imagines that angels could 'see' the atomic structure of matter). In other words, he hasn't fully grasped the nature and implications of hypothetico-deductive explanation.

I think you need to say something about modern physics and its contrast with Newtonian physics and corpuscularianism in order to adequately respond to the second part of the question.

Also, perhaps even more relevantly, an examiner would want to know how you would defend Locke against Berkeley's criticisms of the primary/ secondary quality distinction. Here, Locke is on stronger ground, but you will get marks for saying so.

Locke on nominal and real essence

I find it curious that although you recognize that Locke identifies real essences with the micro-structural properties of objects, you still want to say that 'a 'natural kind' like gold is dependent on our conventional ideas of what 'gold' is, and not on any underlying 'natural' nature of the stuff we choose to classify as gold.'

The crucial issue here, as you recognize, is what are our 'intentions' in using a term like gold to classify things that we see. Consider an argument between a chemist someone who claims that pure gold is white, and someone who insists that any metal that isn't yellow isn't gold.

The 'intention' here isn't to pick out Aristotelian natural kinds. Rather, we are seeking (to be somewhat anachronistic) a 'maximally explanatory description' of the world around us. Calling iron pyrites and gold, 'gold', and refusing that label to white gold, leads to a less explanatory classification than one which identifies gold as the element which has the atomic number 79.

Locke, as a philosopher 'clearing away the rubbish that lies in the path' of good science, would surely assent to this. Or so Mackie argues in his book 'Problems from Locke'.

Whether we can say that 'Locke anticipated Kripke' (or Putnam) is moot. You are right to lay emphasis on Locke's repudiation of scholasticism, yet in recent times (with Wiggins, as well as with Putnam and Kripke) Aristotelian essentialism has had something of a comeback. The main difference (and it is a huge difference) is that Aristotle was implacably opposed to atomistic explanations, whereas the new Aristotelianism locates 'essence' firmly within the context of the hypothetico-deductive explanations of science.

All the best,