Monday, January 30, 2017

What is true

One of the most simple and yet most complicated concepts man ever has thought out is “truth”. Everybody knows what it means, namely that statements are according to what they say. Or as Aristotle formulated it in his Metaphysics: “To say of what is that it is not, or of what is not that it is, is false, while to say of what is that it is, and of what is not that it is not, is true.” (1011b25) Nevertheless everybody also knows how difficult it can be to determine whether a statement is truly true. As the Stanford Encyclopedia of Philosophy says it: “The problem of truth is in a way easy to state: what truths are, and what (if anything) makes them true. But this simple statement masks a great deal of controversy. Whether there is a metaphysical problem of truth at all, and if there is, what kind of theory might address it, are all standing issues in the theory of truth.” (from the entry “Truth”) No wonder that there are many theories that explain what “truth” involves and a lot more secondary books and articles about these theories. Here I cannot treat even a little section of this literature and do justice to what has been written about “truth”. Nevertheless I want to say a little bit about it.
I start with an example that I also used when I discussed the so-called Gettier problem in one of my blogs, although I have changed it a bit (see my blog dated Nov. 12, 2012):

I am worried whether my best cow Betsy hasn’t been stolen from the field where she is supposed to be at pasture. I walk from my farm to the field, where I see a cow in the middle of the herd that exactly looks like Betsy and I am 100% convinced that she is Betsy. Therefore I don't find it necessary to walk to her and check her earmark. I walk home again and say to my wife: “Betsy is in the field”. However, I often confuse Betsy with Jane, when I look from a distance to her, and also now I actually saw Jane. Nevertheless, Betsy is also in the field, and I have seen her, too, for Betsy was grazing left of Jane, and I have seen both cows. However, I thought that the cow left of the cow I mistook for Betsy was Jane.

The Gettier problem is about whether I know whether Betsy is in the field. When talking about truth we have a related problem: Is it true that Betsy is in the field? Or rather, since truth is about statements: Is what I say to my wife – namely “Betsy is in the field” – true?
I think that according to most theories of truth – whether it be the correspondence theory of truth, the coherence theory of truth, the consensus theory of truth, or whichever – the statement that Betsy is in the field is true, if taken as such. And when I said to my wife “Betsy is in the field”, I wanted to say that the cow with earmark HW123 is in the field – since HW123 is Betsy’s earmark – and so that Betsy, the cow with earmark HW123, is in the field. That’s true, indeed. Nevertheless, at the moment that I am saying this statement to my wife, in my mind “Betsy” refers to a cow at a certain place in the field right of the cow I had mistakenly identified as Jane. Let’s suppose that Jane has earmark HW122, and that when I utter to my wife the statement “Betsy is in the field”, I have an image of two cows in my mind and I mean to say that the right cow is in the field. In this statement “Betsy” refers to the cow with earmark HW122 and this statement is false, even though Betsy is in the field, and Jane is also in the field, and even though also the cows HW122 and HW123 are in the field, and even though I have seen both cows in the field (but had unknowingly mistaken the one for the other). As we see: Statements can be true, even if they are false. What we see and say is not always as it appears to us.

Monday, January 23, 2017

Molyneux’s Problem

The case of a flagpole that casts a shadow on the ground, which I discussed last week, is an instance of how counterexamples can undermine theories. However, this counterexample was theoretical in the sense that one didn’t need actually put a flagpole somewhere and make observations. Often a theoretical case will not do and we need a real experiment for solving a philosophical issue. In this way one of the most intriguing questions in modern philosophy has been answered: the Molyneux question.
In 1688 the scientist and politician William Molyneux sent a letter to John Locke in which he presented him with the following question, quoted by Locke in his An Essay Concerning Human Understanding (Book II, ch. ix, §8):

“Suppose a man born blind, now adult, who has learned how to distinguish by touch between a cube and a sphere of the same metal and about the same size, so that he can tell when he handles them which is the cube and which the sphere. Now suppose the cube and sphere to be placed on a table, and the blind man be made to see. Can he by his sight, before touching them, tell which is the globe, which the cube?”

Molyneux thought that the answer was no, and so did Locke. However, this was not the end of the discussion but just the start of it. Through the ages, the question attracted the attention of many philosophers and scholars, like Berkeley, Leibniz, Helmholtz, William James, etc, to this day. It’s no wonder, for its answer has important implications for the theory of perception. A negative answer, so Gallagher, implies a theory in which a meaningful access to the world is mediated and performed by different sense modalities that have to be coordinated. A positive answer implies a more direct access to the world based on innate properties. But how to get an answer? An empirical solution would be most obvious, but as long as it wasn’t possible to perform eye operations, only a theoretical reply remained. However, in 1728 William Cheselden published an account of a successful cataract operation in which he noted that the boy operated was not able to recognize a cube from a sphere. This pointed to a negative answer. Nevertheless doubts remained on methodological grounds, for it was not clear whether the boy had been able to make valid perceptual judgments because his eyes had not been functioning properly. Also later eye operations followed by tests were not without ambiguities, for example when there were doubts about the onset of the blindness in the cases studied or there was confusion about the experience of the patient after the operation. Therefore a positive or negative answer to the Molyneux problem couldn’t be given. Actually this was not a matter of how to answer the question but of the dearth of patients who met all methodological requirements, especially in the Western countries, where congenitally blind patients are treated ìn infancy, if possible, so that they are not suitable as test persons.
However, how cynical, useful patients can be found in developing countries where medical facilities for early eye operations are often present but many people who need it don’t get it because of inadequate medical services. So, in 2003 Pawan Sinha, a professor at the Massachusetts Institute of Technology, set up a program in India and as a part of it operated successfully five blind patients who met the methodological requirements and tested them. The answer to the Molyneux question was negative: The patients who could distinguish a cube from a sphere by touching them couldn’t do so by perceiving them. The result of the vision test was barely better than if the test persons had guessed.
After three centuries of discussion and testing the conclusion is that man has to learn to see – which was already known from other research, of course –; that a meaningful access to the world is mediated; and that what one sense modality already “knows” is not automatically passed on to another sense modality. Nonetheless, this doesn’t involve that sense modalities function completely independent of each other. For – paraphrasing Gallagher – to take the case of vision discussed here, the structure necessary for seeing has never been used by congenitally blind persons, and therefore the neural networks for seeing are completely absent in their brains, or present only in a rudimentary form. But it is quite well possible, and not unlikely, that congenitally blind people learn to see and discern much faster, once they have been operated, because of what they learned before with the help of their other senses.

- Shaun Gallagher, How the body shapes the mind. Oxford: Clarendon Press, 2005; ch. 7.
- Stanford Encyclopedia of Philosophy, “Molyneux’s Problem”, on

Monday, January 16, 2017

Hempel and the flagpole

Robert Marchand is not only a good cyclist at his age of 105, he is also a good scientist. For before his ride by which he set up the new world record in one-hour track cycling in the over-105 age group he said: “I am here to prove that at 105 years old you can still ride a bike.” So, he organised an experiment with a 105 years old person (himself) that he seated on a bike and let him make a ride of an hour. And so he proved his hypothesis that a 105 years old person can ride a bike. Okay, it’s not exactly correct that he proved that at 105 any person can ride a bike, but that there is at least one such a person who can, namely Robert Marchand. Let us forgive him for this slip up in view of his splendid performance.
We wouldn’t have forgiven him if he were not only a cyclist with an established name but also a methodologist with an earned reputation. And since it is always interesting to look at old cases, I want to return to Carl G. Hempel, one of the most important methodologists of the last century. Despite his merits – and I want to say that, although I have never been a fan of his approach – Hempel sometimes made weird mistakes, as we have seen a few weeks ago, when I discussed the raven paradox. We saw there that Hempel thought that the fact that an apple is red – if it is – can confirm that ravens are black. It’s not the only mistake Hempel by made and nor is it his most important one. One of the basic characteristics of Hempel’s methodology – called “covering law theory” – is that explaining the occurrence of a phenomenon and predicting that a phenomenon will occur are two sides of the same coin. Explanation and prediction are symmetric in his view, or, as he calls it, “structural identical”. This thesis is the conjunction of two sub-theses, so Hempel (p. 367): (i) “every adequate explanation is potentially a prediction” and (ii) “every adequate prediction is potentially an explanation”. Although sub-thesis (i) is correct, the weird thing is that Hempel actually also supports sub-thesis (ii), although after some discussion he admits that it is an “open question” (p. 376). However, it is crystal-clear that sub-thesis (ii) is false, as several philosophers have shown. Let me take the refutation by Wesley C. Salmon of (ii) (pp. 101-2) for making clear why.
We can predict a lunar eclipse if we know the positions of sun, earth and moon and the relevant laws of motion. This eclipse can be retrodicted using posterior conditions and the same laws. However, so Salmon, “if explanations are arguments, then only the predictive arguments can qualify as an explanation, and not the retrodictive one. The reason is obvious. We explain events on the basis of antecedent causes, not on the basis of subsequent effects (or other subsequent conditions)”. This becomes even clearer from Sylvan Bromberger’s flagpole example. If we know the elevation of the sun in the sky and the height of a flagpole, we can compute the length of the shadow of the flagpole; or if we know the length of the shadow, we can compute the height of the flagpole. However, only the presence and height of the flagpole explains the occurrence and length of the shadow but not the other way round. It is because “a causal process is involved, and that the light from the sun must either pass or be blocked by the flagpole before it reaches the ground where the shadow is cast” (italics Salmon). This refutation of sub-thesis (ii) is considered by some so fundamental that they call it the “killer” (Peter Godfrey-Smith) of Hempel’s covering law theory. Nonetheless, Hempel never revised his theory in light of the flagpole counterexample, which was put forward already one year after the publication of his Aspects... .

References: - Carl G. Hempel, Aspects of Scientific Explanation and other Essays in the Philosophy of Science. New York: The Free Press, 1965.
- Wesley C. Salmon, Causality and Explanation. New York/Oxford: Oxford University Press, 1998.

Monday, January 09, 2017

Setting targets, also when you are 105

Robert Marchand, setting up a world record in one-hour track
cycling in the over-105 age group on Jan. 4, 2017

Maybe you have taken one or more New Year resolutions at the start of the new year. However, there is a good chance that you’ll not keep them or maybe you have already forgotten them by the time you read this blog. The reason is that most New Year resolutions are too vague: they don’t mention a date when they have to be fulfilled and they don’t tell which specific aim you want to reach. You decide to lose weight this year, but when you haven’t done it yet on December 30, you can say that you’ll have yet one day ago, but in fact it’s too late. Moreover such a resolution doesn’t say how much weight you want to lose. One gram? Ten kilos?
Every sportsman knows that if you want to achieve a goal, you must determine exactly what you want to achieve and that you must make a plan. And, of course, you must keep yourself to the plan – and not change it too much while you are working with it – for otherwise it is almost certain that you’ll fail. For instance, a long distance runner decides that he wants to run the marathon within three hours and then his plan says how often in a week he will train, and from day to day whether the workouts will be filled in with intervals or endurance runs, how fast he will run the intervals and the endurance runs etc., and when he’ll run the marathon. And so it’s the same for losing weight: Make a plan how many kilos you want to lose each month and what your diet will be. So far, so good. “Everybody” knows it, and hardly anybody does it, when taking New Year resolutions, and so they fail. Or they have simply forgotten their New Year resolution.
Although the time to set New Year resolutions has gone, it is not too late to set targets, for you don’t need to do it at the first day of the year. You can do it any time and you should certainly do it, for setting targets is an important condition for good life. Targets structure your life, they help make your life successful and they contribute to your feeling of happiness. And you are never too old for it. Really. Take Robert Marchand, the French cyclist who became 105 years old, last November. You know from my last blog that he is still active in cycling and that he even holds the world record in one-hour track cycling in the over-100 age group. But he needed a new challenge, so Robert Marchand set himself the target to get the world record in one-hour track cycling in the over-105 age group. However, there was no official over-105 age category in international cycling. No problem: it was created for him. But alas, the rules prescribe that for a record in one-hour track cycling you need to use a bike without brakes and without a freewheel. When Marchand was younger, riding such a bike didn’t cause difficulties, but at the age of 105 you don’t sit as firmly in the saddle anymore as a young fellow. Again no problem: The rules were adapted so that for this new track record it is allowed to use a normal race bike with brakes and a freewheel. And so it happened that last week, on January 4, Robert Marchand set up the new world record in one-hour track cycling in the over-105 age group in the unbelievable time of 22,547 km on the National Velodrome at Saint-Quentin-en-Yvelines near Paris! Take your hat off to that! And pattern yourself to Robert Marchand and learn from him that you are never too old for setting targets. Old people were too long seen as people in terms of objects who need care and have nothing else more to wish. It’s true, often the elderly need care, and I wouldn’t be surprised if Robert Marchand needs some age related care as well, now and then. But Marchand shows us that also at an advanced age you can live life to the fullest, and that the elderly are maybe vulnerable but complete individuals who can live possible futures filled with perils and promises – as the philosopher Jan Baars words it – and who can set targets, indeed.

On the Internet there is a lot on setting targets and on Robert Marchand. Some on Jan Baars and his philosophy of ageing on

Monday, January 02, 2017

How to celebrate your birthday: Robert Marchand

Philosophers seldom write about the ordinary things in life, which are nevertheless meaningful from a philosophical point of view. When doing some research for my last blog I had to conclude that one of the few philosophers who writes about Christmas is Wittgenstein, but actually his remarks on Christmas are casual and they have hardly anything to do with its philosophical meaning. When you want to read about the meaning of our daily – often “banal” – activities, you get at sociologists like Michel de Certeau and Marc Augé. It’s true that the Swiss-British philosopher Alain de Botton writes about everyday themes like travelling or the news and what they mean for our art of living; themes that are more sociological than philosophical and that are avoided by most – but not all – other philosophers. But who writes philosophically about such an ordinary theme like birthdays?
In many countries outside the western world birthdays don’t count. They are not important and often ignored. Nowadays, dates of birth are registered everywhere, of course, but when people are asked how old they are, they often reckon only from the year they have been born. Whether they have passed already the date of birth at the moment they are asked for the age is not important for them. What’s more, for some people even the exact year of birth is not important. A vague indication of age suffices, as a person working with immigrants in the Netherlands told me.
How different it is in many western countries. It’s clear that I cannot speak here about all countries and cultures, but in countries like the USA, Germany and the Netherlands birthdays are really important. They are so important that you simply must celebrate them. The practice is, of course, that a substantial number of people doesn’t but also they do it in some way: If you don’t celebrate your birthday you must have an excuse why you don’t. It simply cannot be ignored, full stop.
How do people celebrate their birthdays? Preferably a birthday needs to be celebrated on the day itself, but when that isn’t practical or possible, usually it’s celebrated on a day in the weekend before or after the actual birthday. Then a party is held, big or small, the guests are treated, presents are given, and striking birthdays (like coming of age, or the 50th) are often celebrated in a special way, etc. I don’t need to go here into detail, since everybody knows. How interesting would it be to make a full philosophical study of this, for not everybody celebrates his or her birthday in the same standard way. Some people chose just the birthday for doing something special. They go to the theatre on that day. They make a long walk, alone or with others. Or they take a short holiday break, especially on striking birthdays, instead of giving a party (or they do both). And did you know that in the Netherlands on a birthday party you have to congratulate also the partner and family of the person whose birthday it is, and that the latter has to treat also his or her colleagues on his/her workplace?
But when you become older? Most people tend to give less and less attention to their birthdays after a certain age. Their children and close family and friends come to congratulate them, they treat them to cakes, and some call them up if they cannot come, but that’s all. Not so Robert Marchand, a French cyclist. What was his greatest wish to do on his 103th birthday? To take his race bike and to climb the Col Robert Marchand in the Ardèche in his country (he himself lives near Paris). However, there were two problems: the weather was not really good on this 26 of November and actually he wanted to climb only slopes that are at least 15 degrees, and this one is 11 degrees. But okay, it was his birthday, and so he conquered the 10km climb in under an hour, and at the top he took a glass of Champagne. On his 104th birthday, he cycled some 20 km of a stage of the Tour the France cycle race of that year in the Ardèche. And he celebrated his 105th birthday a few weeks ago by cycling 26,927 km with friends from his cycling club. Why just this distance? Because it is the world record in one-hour track cycling in the over-100 age group. I suppose that I don’t need to tell you that the record is his (cycled on January 31, 2014). But the real way he’ll celebrate his 105th birthday has yet to come, on Jan. 4 next (see my blog next week). Should I still explain how philosophically meaningful birthdays are for understanding ways of life?