Shades of blue

The cases of Swampman and Teletransport discussed in my blog last week are so-called thought experiments. These are experiments that are performed only by reasoning, so in the mind, since they cannot be performed in real for often obvious reasons. Thought experiments belong to the oldest instruments of philosophy and I have discussed them in my blogs as well. When one searches the Internet for lists with the most important thought experiments, it’s striking that these lists are very different, although some such experiments are mentioned on several lists, like “Swampman” and “Teletransport”. One that often fails is Plato’s Allegory of the Cave. I am a bit surprised for I thought that it’s the most famous thought experiment, one that “everybody” or at least every philosopher knows.

Thought experiments can provide deep insights, but a problem is that with many thought experiments are meant to prove what they actually already assume; or that the results follow from doubtful suppositions. Parfit’s Teletransport is a case in point. After having been teletransported Parfit’s wakes up and says “Examining my new body, I find no change at all.” (see my blog last week) With the help of this thought experiment Parfit reasons then that there is a psychological connectedness between Parfit on Earth and the teletransported Parfit on Mars. Leaving aside my criticism last week – which one could call “immanent” because it accepts the view that teletransport is a real possibility – I want to raise here a more fundamental point, namely that assuming the feasibility of such a teletransport is not right at all, unless it has been proven in practice. For I think that teletransport is not possible in the sense that Parfit wakes up on Mars and thinks that he is the person who just has been teletransported from Earth. One cannot correctly assume that it happens without any further reasoning or test. There is a simple argument against the idea: There is no intrinsic need to destroy Parfit on Earth when he is teletransported, and when we would omit Parfit’s destruction on Earth, there would be two Parfits thinking “I am Parfit”. Parfit on Earth is right, so Parfit on Mars cannot be, for he is not more than a copy. He remains a copy whether we destroy Parfit on Earth or whether we don’t. In my last blog I argued that Parfit’s reasoning was false, here I more fundamentally argue that Parfit’s thought experiment is false, since it is based on false assumptions.

To take yet another possibly false thought experiment, in his A Treatise Concerning Human Understanding David Hume wants to defend the thesis “that all our simple ideas in their first appearance are derived from simple impressions, which are correspondent to them, and which they exactly represent”. So first there is the observation and only then there is the idea. After having discussed two kinds of phenomena that support this thesis, Hume says: “There is however one contradictory phaenomenon, which may prove, that it is not absolutely impossible for ideas to go before their correspondent impressions.” For take this thought experiment: “Suppose ... a person to have enjoyed his sight for thirty years, and to have become perfectly well acquainted with colours of all kinds, excepting one particular shade of blue, for instance, which it never has been his fortune to meet with. Let all the different shades of that colour, except that single one, be placed before him, descending gradually from the deepest to the lightest; it is plain, that he will perceive a blank, where that shade is wanting, said will be sensible, that there is a greater distance in that place betwixt the contiguous colours, than in any other. Now I ask, whether it is possible for him, from his own imagination, to supply this deficiency, and raise up to himself the idea of that particular shade, though it had never been conveyed to him by his senses? I believe there are few but will be of opinion that he can; and this may serve as a proof, that the simple ideas are not always derived from the correspondent impressions”.

Now I think that this objection to Hume’s just mentioned thesis would be enough to falsify it. Not so for Hume. After having presented the thought experiment his conclusion is: “[T]he instance is so particular and singular, that it is scarce worth our observing, and does not merit that for it alone we should alter our general maxim.”

Be it as it may, is it right that the person in Hume’s case can supply “from his own imagination ... this deficiency, and raise up to himself the idea of that particular shade”, as Hume thinks? Helen De Cruz describes this experiment on the “Bored Panda” website and has added a drawing of several shades of blue with one missing plus a man in a blue sweater by way of illustration (see the link below). However, she adds: “Curiously though, when I presented this drawing to friends, they thought the man’s sweater was the missing shade of blue, but it isn’t! So perhaps it is not so easy to fill in the gap after all.” Maybe we cannot fill in the shade of blue simply by our imagination at all! What Hume assumes here in his mind needs to be proven in an experiment before we can accept it. As long as it hasn’t been performed, Hume’s blue shades case doesn’t refute his thesis. However, this thesis must be refuted for other reasons, which I’ll not discuss here.

References

- De Cruz, Helen, “8 Philosophical Thought Experiments That I Illustrated To Broaden Your Mind”, on website

 https://www.boredpanda.com/im-a-philosopher-who-has-illustrated-a-series-of-philosophical-thought-experiments/?utm_source=google&utm_medium=organic&utm_campaign=organic

- Hume, David, A Treatise Concerning Human Understanding, Book I, Sect.I, on website

http://www.gutenberg.org/files/4705/4705-h/4705-h.htm

The Swampman

Some examples devised by philosophers are weird but analytically very useful. Take this one by Donald Davidson:

“Suppose lightning strikes a dead tree in a swamp; I am standing nearby. My body is reduced to its elements, while entirely by coincidence (and out of different molecules) the tree is turned into my physical replica. My replica, Swampman, moves exactly as I did; according to its nature it departs the swamp, encounters and seems to recognize my friends, and appears to return their greetings in English. It moves into my house and seems to write articles on radical interpretation. No one can tell the difference.

But there is a difference. My replica cannot recognize my friends; it cannot recognize anything, since it never cognized anything in the first place. It can’t know my friends’ names (though of course it seems to); it can’t remember my house. It can’t mean what I do by the word ‘house’, for example, since ... [it] was not learned [by Swampman] in a context that would give it the right meaning – or any meaning at all. Indeed, I don’t see how my replica can be said to mean anything by the sounds it makes, nor to have any thoughts.” (source: see below; italics in the original)

Much can be said about this example and much has been said about it. I think that it gives some answers but raises many questions, too. Anyway, I think that you’ll agree that Swampman is not Davidson.

Take now this case by Parfit: “I enter the Teletransporter. ... This machine will send me at the speed of light [to Mars]. I merely have to press the green button. ... When I [do], I shall lose consciousness, and then wake up [an hour] later. ... The Scanner here on Earth will destroy my brain and body, while recording the exact states of all my cells. It will then transmit this information by radio ... [to] the Replicator on Mars. This will then create, out of new matter, a brain and body exactly like mine. It will be in this body that I shall wake up.” Parfit presses the green button and wakes up on Mars: “Examining my new body, I find no change at all.” (source: see below)

Next Parfit discusses the relevance of his example for the problem of personal identity. However, is it possible to be teletransported in this way? Parfit’s example suggests that the answer is yes, but after having read Davidson, the answer is clear: No. From Davidson’s discussion we can learn that Parfit on Mars is not a kind of resumption of Parfit on Earth. For instance, what Parfit’s Mars-Replica knows was not learned by him in a context that would give it the right meaning (see above). It’s simply a copy, just as a copy of a letter is a copy of a letter and not the original, even though it has the same contents and the same layout. Moreover, in the case of the teletransport the original has been destroyed, just as Davidson has been by the lightning in the Swampman example. There isn’t even a (psychological) continuity between Parfit on Earth and his replica on Mars, as Parfit thinks, for there is no logical necessity that Parfit on Earth must be destroyed; just as we don’t need to destroy the original letter once we have copied it. A copy is not a continuation of the original but duplicate of it.

However, copying Davidson to Swampman or Parfit to Replica-Parfit doesn’t need to happen all of a sudden. Think of the Ship of Theseus: Theseus returns from Crete to Athens, after having killed the Minotaur, and has to repair his ship at sea. He replaces the old planks of the ship one by one by new ones so that finally none of the old planks of the ship that left Crete remains. Then the question is: Is the ship that arrives in Athens the same one as the ship that left Crete? To my knowledge there has never been given a satisfactory answer to this question. If one looks at the ship when it left Crete and then again when it arrived in Athens only, one tends to say “no” in view of Davidson’s case. On the other hand, I think that the sailors had always the idea that they used the same ship. And how about halfway Crete and Athens? The questions become even more intriguing, if you realize that man is like the Ship of Theseus: Man is continuously under construction and reconstruction. Man is continuously repaired and renewed and after some years none of the molecules we originally consisted of are yet the same. Then the question is: Are we the same as we are? You know the answer for yourself but it seems that the Swampman example is not as weird as it might seem on the face of it. Think about it, and the more deeply you go into it, the more you’ll discover in it.

References

- Davidson, Donald. “Knowing One's Own Mind”, in his Subjective, Intersubjective, Objective. New York: Oxford University Press, 2001; p.19.

- Parfit, Derek, Reasons and Persons. Oxford: Clarendon Press, 1984; pp. 199, 215.

Internet in the 17th century

Today we have the Internet. We use it for exchanging messages and information, not only privately but also, for instance, in science and in philosophy. However, how kept scientists and scholars in touch during the age of the rise of modern science and philosophy, so in the time of Descartes, Spinoza, Locke, Boerhaave, Newton, Huygens, and others, when the Internet did not yet exist? For it’s clear that science and philosophy were not lonely activities then, but that workers in these fields knew about each other and built relationships. They had extended networks and they had also a name for it: The Republic of Letters.

The term “Republic of Letters” dates from the 15th century, but its main period was from about 1500 till 1775, the time of the rise of modern science and philosophy. What has been meant with “Republic of Letters” has always been a bit vague, but here I refer to a system of human relationships. As Hans Bots describes it in his book that I have used for writing this blog: The lettered persons were part of an ideal state or republic that was above the existing political units in Europe. It had its own rules and laws. The lettered people felt themselves “citizens” of this community and behaved publicly like that and they saw themselves as equals. Ideally reason and truth were their highest authorities. These characteristics were important in view of the fact that the political states were continuously at war with each other. Therefore the scholars needed a way of cooperation that kept aloof of these conflicts and that allowed them to go along with each other without being divided by politics. The Republic of Letters was for them a kind of state above the political state. Its citizens were the intellectual and scientific elite of those days. Not social rank or position was important for its citizenship but nobility of the mind.

How did the participants exchange ideas and information? Basically there were four ways for this. Most important was personal contact with other members of the intellectual elite. This was easy when you lived in or near a town that was a centre of intellectual culture or even had a university. But also in those days already people travelled a lot; especially the elite did, including the intellectual elite. Erasmus travelled through many parts of Western Europe; the Dutchman Huygens went regularly to Paris and has also lived there for some time; Descartes moved from France to the Netherlands and later to Sweden, and he has also visited other countries. Many others did so. However, if you hadn’t the opportunity, time or money to travel, there was an alternative: writing letters. Letter writing tends to become a forgotten activity, but in those days this means of communication was very important. The postal services had gradually improved and it lasted only a few days to send a letter from, say, Amsterdam to Paris. But sending letters was expensive and risky. They could easily be lost because of wars, raids or other circumstances, so the best way to send a letter was to give it to a traveller you knew.

And there were books. Since the invention of the art of printing, it had become easy to duplicate books. However, books were censored everywhere. Usually the author or publisher needed consent from the authorities before they were published. The Netherlands were an exception and here censorship was less strict than in other countries. Moreover, if books were censored there, it was always after the publication. As a consequence the Netherlands became a centre for printing “dangerous ideas” and spreading them all over Europe.

All these methods of exchange existed already before the rise of the Republic of Letters, but the Republic invented also a new method: journals. Because of the growing number of books and scientific discoveries and inventions, people lost an overview of what was happening in the intellectual world. It became impossible to read every interesting publication, so there came a need to summarize what was happening in the learned world. Already about 1620 the first periodicals with political and commercial news had been published in Amsterdam. It had yet to wait until 1665 before the first scientific journal came out. It was in Paris. This Journal des Savants contained summaries of books and reports of new research. It was soon followed by other such journals, especially in the Netherlands, but also, in London and elsewhere. In Rotterdam the Frenchman Pierre Bayle made himself useful by developing this new medium. Also in 1665 the Philosophical Transactions was published in London. It contained only reports of scientific experiments and in this sense it is the first modern scientific journal.

Journals were especially useful for those who didn’t live near a library or intellectual centre. Actually any town or court of a noble man or woman with an intellectual interest could be such a centre, but two centres stood out. Most important was Paris, but the Netherlands was almost as important. It was a new state where, as we have seen, censorship was almost absent and printing houses flourished, especially in Amsterdam and Leyden. Moreover the new University of Leyden, established in 1575, attracted by its modern structure the best professors and students of the time.

Life today is unthinkable without the Internet, but the Internet as a modern way of communication in the scientific world is not much older than about 25 years. Therefore, in the period of the rise of modern science and philosophy they needed a communication system of their own. They called it the Republic of Letters.

This blog is based on Hans Bots, De Republiek der Letteren. Nijmegen: Vantilt, 2018.

Embodied cognition

Knowledge is not only in the brain. With this statement I don’t mean in this blog the “extended mind thesis”, which says that a part of the mind is outside the brain in the agent’s world. For instance, you have stored a mailing list in your computer and you know in which file it is, so you don’t need to have the addresses in your mind. No, in this blog I mean with my statement that your knowledge is in your whole body. This thesis is called “embodied cognition”. Last week I discussed already an instance of it.

Actually the thesis doesn’t represent one view. As the Stanford Encyclopedia of Philosophy says in its introduction to the theme: “Embodied cognitive science encompasses a loose-knit family of research programs in the cognitive sciences”. The family shares its critique against traditional approaches but each member tries to find her own solutions. Here I cannot even try to give a full treatment of the theme, but I’ll give some illustrations so that you get an idea what it is about.

My description of embodied cognition last week was rather vague. This one from the Stanford Encyclopedia of Philosophyis much clearer: “Cognition is embodied when it is deeply dependent upon features of the physical body of an agent, that is, when aspects of the agent’s body beyond the brain play a significant causal or physically constitutive role in cognitive processing.” The definition says that there is more knowledge in the body than we find in the grey matter in the head. One of my favourite examples to show how this can be is the case of a runner. Broadly it is so that there are two types of runners: sprinters and long-distance runners. Of course, everybody can choose to become a sprinter and train as hard as s/he can and so become better and better. Nevertheless whether s/he’ll become a good sprinter depends not only on the training but also on the features of his or her muscles. Just as we have an inborn capacity for language learning, we have an inborn capacity for becoming a good sprinter. A person with the type of muscles for a long-distance runner will never become a good sprinter. And the same story for the athlete who wants to train for a 5K or a marathon. In other words: Your legs have a kind of knowledge about running a sprint or running a long distance. However, this is not the whole story, for talented or not, everybody will become better in the chosen speciality by training. The muscles become stronger, the blood transport in the legs improves etc. And the next time you are going to train this increased capacity is still there. So your legs have “learned” to adapt to the training (just as you’ll become better by practicing a language you are learning). You have got more knowledge but this knowledge is not in your head but in your muscles.

I want to add another example, which I have taken from the website of Psychology Today (see Sources below). The web post there explains that there are two very different kinds of robots, here exemplified bij Honda’s ASIMO and the Boston Dynamics Big Dog. Let me quote:

“Honda’s ASIMO literally implements a traditional cognitive, computational approach. Everything it does is the output of complex internal programmes which control everything he does. Honda are fond of trotting him out to dance, run, and climb stairs; he can do all this, but it’s very fragile. Minor disruptions throw him entirely (e.g. a minor error in foot placement and he falls ...; hide his pre-set landmarks with a little clutter and he completely fails to navigate his way across a room). He’s slow, and inefficient; if you knock him, he needs time to recompute his behaviour or else he falls, and he often doesn’t have the time. [The] Boston Dynamics Big Dog[, on the other hand, can] walk over rough, uncertain terrain while carrying heavy loads[. The designers] knew that the computational strategy was too slow and cumbersome. So they instead built a robot with springy legs and joints that mimic the kind of dynamical systems seen in animal quadrupeds. Big Dog has very little brain; the specific movements he produces ... emerge from the interaction between his moving legs, the surface he’s on and any other forces acting on him. If you knock Big Dog, he doesn't need to recompute his behaviour; he simply responds to the new force and the details are left up to his anatomy (his leg moves where it goes because that’s the way it’s built).” (italics mine) This is not only the way Big Dog moves. As stressed by me in the quotation Big Dog’s walking is copied from the way animals walk and, I assume, man walks as well.

The embodied cognition thesis says that knowledge is not only in the brain but in the whole body. I presented here two cases that illustrate the thesis, but there is a growing number of studies that substantiate the view. I’ll mention only a study by Shaun Gallagher, one of my favourite authors in the field (see Sources below). But if it works this way, it has consequences for our self-understanding and, for instance, for our idea of free will (a theme also discussed by Gallagher). It looks as if your body can behave against “your” will. But do we also say so when you drive a self-driving car? Of course not.

Sources

- For the Stanford Encyclopedia of Philosophy: https://plato.stanford.edu/entries/embodied-cognition/#toc

- For Psychology Today: https://www.psychologytoday.com/us/blog/beyond-words/201202/embodied-cognition-what-it-is-why-its-important

- Gallagher, Shaun, How the body shapes the mind. Oxford: Clarendon Press, 2005