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Essays on Heraclitus, testimony and tomatoes


To: Stuart B.
From: Geoffrey Klempner
Subject: Essays on Heraclitus, testimony and tomatoes
Date: 25 April 2007 10:50

Dear Stuart,

Thank you for your email of 16 April, with your University of London essays in response to the following questions:

''The ordering, the same for all, no god or man has made, but it was, is and will be: fire ever-living, being kindled in measures and going out in measures.' (Heraclitus fr. 30.) Discuss.'

'Much of what we ordinarily call knowledge involves information that we believe only on the basis of what others have told us - i.e., on the basis of testimony. What conditions have to be met for us to gain knowledge from the testimony of others?'

'What is the relation between perceiving the redness of a tomato and knowing that the tomato is red?'


This is a very good essay with which I have few disagreements. The only problem was that despite having a Greek font on my computer the quotations reproduced as lines of question marks.

In an exam, it is OK to use transliteration, e.g. 'cosmos', 'psuche', etc.

You gain marks for showing that you know the context from which the quote was taken, as well as for giving plausible alternative readings and explaining their consequences.

I think that there is probably more scope for philosophical discussion than you have allowed (in other words, you are over-correcting in response to my previous comments).

In particular, there is a lot of philosophical meat in the issue over the traditional view of omnipresent flux and the view preferred by a number of recent commentators including Kirk and Raven that all Heraclitus was saying is that all things are in a process of change but 'not all at once'.

Both alternatives deserve to be explained more fully. I may have mentioned that I prefer the traditional view. There is no 'substance' as Thales, Anaximander and Anaximenes believed.

According to Kirk and Raven, on Heraclitus' theory some things change rapidly, while other things change very slowly. If we were to look very closely at a rock, for example, we would see that the rock was undergoing a process which, over a few thousand or hundred thousand years would produce a visible change. In other words, in this world, nothing is immutable. But how does that contribute to the on-going debate? Thales or Anaximander or Anaximenes could have said the same.

There is a tension here with your describing as 'traditional' the view that the substance of the universe is 'fire'. However, this can be resolved by replacing 'substance' with 'arche'. The point of the Platonic view is that everything is the kind of thing that fire is; only fire demonstrates this in the most spectacular fashion. Nothing has any substance, everything is like fire, or like a river.

Does it follow that there can be no knowledge of anything? Plato has an agenda - to argue that even though the phenomenal world is just as Heraclitus described it, there also exists a world of forms in virtue of which language and communication are possible. However, Heraclitus has an adequate response without recourse to a theory of forms: we 'know' objects by conventional names, like 'river', and these are the currency of normal discourse. What we don't know - or only dimly grasp as a result of wrestling with Heraclitus' theory - is the ultimate constitution of things which can only be approached by means of similes and metaphors.

Heraclitus thought that he was putting forward a radical proposal which few mortals were equipped to grasp. The alternative interpretation just doesn't seem radical enough.


I couldn't find any specific things to disagree with here. The main problem is that although you mention or allude to different views such as coherentism, contextualism, reliabilism, tracking truth most of what you say just seems like a recapitulation of common sense. In other words, it is hard to identify targets for critique.

When I was at Oxford, Gareth Evans - then a rising star in the philosophical world, before his untimely death - was talking about the problem of testimony as one of the most exciting and challenging problems in semantics and epistemology. Can you think why?

There are various moves one can try to make. How are things different if we imagine a visitor to another planet who has to decide, from scratch, whether to believe what he is told by his alien hosts? What does the answer to that question show about the importance of the role of a shared language and nature?

Or imagine a young child abandoned on a desert island with a library of books. The child grows up, teaches himself and learns about the world. What is he missing? Does he 'know' less?

What is the significance of the fact that I am not the end point in the chain of information transmission but am myself called upon to testify for someone else's benefit? If the knowledge is for me, I can make an assessment depending on the risk, as you say. But if I am to testify to someone else, what standards should I employ, not knowing what use that person wants to put the knowledge so gained?

Is the credibility of knowledge claimed weakened as the chain lengthens? If not, why not? We do normally raise questions, e.g. when reading a newspaper article, as to whether what we are reading is first-hand or second-hand information.


I am still not convinced that the sense datum theory and phenomenalism are relevant to this question, at least not to the core of what the question is about. Of course, you can ask what the sense datum theorist or phenomenalist would say, and get some mileage but there remains a core issue even when these alternatives are rejected.

The fact that we don't (or, rather can't) attend to all the features of our visual field at any one time can be explained in terms of Dennett's distinction between levels of conscious 'awareness'. For example, driving along in a car while thinking about this essay question, you might stop at several red lights and then go promptly on green without every consciously applying the concepts 'red' or 'green' to your experience.

No-one observing your behaviour would doubt that you perceived the greenness of the traffic light. However, equally, one would say that you knew that the traffic light was green. If you didn't know that it was green then that would be a case of reckless driving. For example, if the sun is coming from the wrong angle you might need to crane your neck or squint your eyes before satisfying yourself that the light has changed to green. In favourable conditions, by contrast, you just know that the light has changed without thinking about it.

All the best,