Holding positions rationally
September 28, 2013 8 Comments
Many people seem to think that rationality consists of holding certain positions that are justified (shown to be true or probably true) – justified true belief. For example, you are supposedly rational if you think that life evolved by natural selection and creationists are irrational. Why? One common answer is that there is lots of evidence for evolution. Thus evolution is not just a theory it is a proven scientific fact or something like that. If you don’t look at this story too closely, you might think it makes sense. There is a lot of evidence that is relevant to the theory that life evolved on Earth by common descent from a single ancestor. However, the idea that positions can and should be justified – justificationism – is a gross misrepresentation of science and rationality more generally.
If you were looking for flaws in justificationism, it wouldn’t be difficult to find them. Newtonian mechanics was not contradicted by the vast bulk of experimental evidence before the 20th century – that’ two hundred years of positive experimental results. But Newton’s theory was replaced by quantum mechanics and general relativity, which contradict one another so they can’t both be true. We don’t know what the replacement will be and it may be the case that there is stuff physicists have badly misunderstood at the foundations of both theories. If physicists are almost certainly misunderstanding a whole load of stuff and don’t have a consistent worldview then it can hardly be said that physics is justified. So by justificationist lights, the whole of physics is irrational.
I picked physics, but I could have picked many other subjects. In biology we don’t understand what sort of complexity DNA can be used to create as a result of natural selection. Would it be possible to evolve creatures that travel through space and colonise other planets purely by natural selection among genes? Human beings haven’t created knowledge about space travel in that way. Rather, we have created a lot of that knowledge through evolution of ideas. And we have virtually no understanding of how evolution of ideas is instantiated in the brain.
And then there’s everyday life. Let’s take brushing you teeth. Can you justify brushing your teeth? People seem to end up doing stuff that is widely recognised as irrational when they undertake activities like politics, personal relationships, work, money, drugs, food, exercise and other stuff. But a lot of it is the same old shit people have been doing for centuries. So what’s the hold up? Why hasn’t it been justified yet and so made rational? Many people will say that such stuff is necessarily irrational. Why? Because we’re apes or something comes the vague reply. This reply doesn’t make sense because it doesn’t explain why all this stuff should be irrational while science is supposedly rational.
Rationality isn’t about the content of your positions, it’s about how you hold them. Justification is not any part of rationality, because justification is impossible. Any argument has to start with premises, so if the premises are not justified nor is the conclusion. And if you try to justify the premises then you need another argument, with more premises that have to be justified.
“Aha!” I hear you cry, “I have got you. For I can look out of my window right now and see lots of stuff like a white van. I can base my worldview on these observations.” This is a terrible argument. Eyewitness testimony is notoriously unreliable. People often misunderstand stuff they see quite badly. They make up stories to try to explain what they see after the fact and this can change what they think they saw.
And people don’t understand the vast majority of what they see. For example, there are some rain drops on my window. Those raindrops are refracting the light from the scenery in front of the window: they bend the path the light takes away from a straight line. I can see colours in each raindrop because it takes the light from some piece scenery and bends it in such a way that it enters my eye and I see it. The optics of visible light for an object as large as a raindrop is fairly well understood. Given enough time I might be able to reproduce what I can see through the raindrops. Most people couldn’t do that calculation since they don’t know the relevant physics, and I’m just not going to do it because it’s not interesting. Now, think about how much stuff in everyday life you don’t understand at that level of detail and you’ll begin to see a problem in taking what you see as totally unproblematic.
So if justification is impossible how can we think and act rationally? What’s needed is a way to try to sort bad ideas from good ones. The way to do that is to take your ideas seriously as descriptions of how the world works and look for problems with them – anything that seems unsatisfactory. You then propose solutions to those problems and look for problems with the solutions until only one is left. Then you start on another problem. Rationality is about solving problems and then moving on to new problems you prefer to the old ones. It’s not about fixing some particular idea in stone. Rather, it is about improving ideas
To the extent that we have succeeded in creating knowledge in subjects like physics and biology, it’s because people have found lots of flaws with their past ideas and discovered new ideas that don’t have those flaws. They have other flaws that are more interesting.
By contrast, it is notable that when it comes to things like politics and personal issues people seldom admit error and almost never look for explanations. For example, when people get married they become dependent on one another to some extent because their finances are bound together, unless they specifically stipulate otherwise in a prenup and prenups can be overturned. But why should two adults be financially dependent on one another? Most of them could afford to rent or buy an abode on their own. Food is cheap. Lots of people could live near to where they work and to shops so they wouldn’t need a car. Many people say marriage is good for raising children, but lots of married people get divorced and hurt their children in the process. There is a lot of stuff here that just doesn’t add up at all and very few people are looking for alternatives.
I’m not sure that evolution is a particularly good example, because it is actually a scientific fact. It strikes me that theories like Newton’s laws are different things from facts like evolution. You would never see Newton’s laws, no matter how long you looked, but if you lived long enough, you would actually see evolution. Then you might want to develop a theory to explain what you encounter in reality. From the point of view of molecular biology, evolution is an inevitable consequence, it almost doesn’t need a separate name.
You can see evolution in exactly the same sense as you see any other scientific law in action. That is, you make guesses about the circumstances under which you would expect to see some feature that is distinctive to that theory as opposed to others, and then look to see what happens. Every step in this process involves making guesses any one of which could be wrong. So in any specific instance where you think you have observed evolution you could be wrong. And in every such case it would not be true that the theory follows from what you’re looking at since the theory isn’t about what you’re looking at: it’s about the underlying reality that produces what you’re looking at. You wouldn’t know where to look without the theory.
It is also bizarre that you say evolution follows from molecular biology when it was proposed before molecular biology. But how could evolution be proposed before much was known about molecular biology? Evolution isn’t about molecules per se, it is about what sort of processes can lead to the creation of complexity from relatively simple beginnings. Those processes have to involve things like faithful copying of information, generating variations of that information and then selecting among those variants. You might want to read The Beginning of Infinity by David Deutsch
http://www.amazon.co.uk/gp/product/B004TRQAP4/ref=as_li_ss_tl?ie=UTF8&camp=1634&creative=19450&creativeASIN=B004TRQAP4&linkCode=as2&tag=conjecandrefu-21
especially chapter 4, and “The Selfish Gene” and “The Extended Phenotype” by Richard Dawkins
http://www.amazon.co.uk/gp/product/B000SEHIG2/ref=as_li_ss_tl?ie=UTF8&camp=1634&creative=19450&creativeASIN=B000SEHIG2&linkCode=as2&tag=conjecandrefu-21
http://www.amazon.co.uk/gp/product/0192880519/ref=as_li_ss_tl?ie=UTF8&camp=1634&creative=19450&creativeASIN=0192880519&linkCode=as2&tag=conjecandrefu-21
Between the moment when someone thought that the Earth might be round as opposed to flat, and the moment someone stood on the moon, there must have been a point when the shape of the earth became a fact. Unless of course you think it still a theory? Perhaps Neil turned to Buzz and said, “It may look round, and we may have orbited it several times, but to hold that it actually is round, would be highly irrational”?
There was the theory that matter is made up of atoms. Do you really think it rational to regard that as a theory as opposed to a fact, and not just something like a fact, but an actual fact? I mean, now that technology has reached the point where we can manipulate individual atoms, I feel an irresistible urge to accept that they are really there. I find it bizarre, that you find it bizarre, that this is the chronological order of things. It was once thought that planets orbit in ellipses. Well, they do, but that’s not why, and we don’t need that theory any more.
I was unaware that Darwin expressed his theory in terms of the creation of complexity and of information in the era prior to the advent of molecular biology. He really was ahead if his time! I had thought he was more into pangenesis and the inheritance of acquired traits!
Nevertheless, you claim that evolution is the theory of how complexity is created from humble beginnings. This leads me to ask, “Why do we need such a theory?”
What purpose does it serve to say that some particular items of knowledge are facts? Let’s suppose that somebody claims the Earth is flat. Just saying “it is a fact that the Earth is round” should not convince him. What should get him to change his mind is an argument that explains why his ideas are wrong. Your knowledge that the Earth is flat is a result of understanding some relevant set of explanations. In this particular instance those explanations have no competitors among people who understand them. Is it rational to regard this as a theory? Yes. Is it rational to regard it as a fact? Yes. I can’t currently imagine any change in my worldview that would lead to me thinking of it as false. Likewise for the other facts you mentioned.
You say you were unaware that Darwin expressed his theory in terms of the creation of complexity and information. I never said he did. What I said was that this was known before they discovered the relevant molecules. DNA was discovered in 1953. Von Neumann was lecturing on the theory of self replicating machines in 1948.
You ask why we need a theory of how complexity is created from humble beginnings. If you look at any biological system or any technological artifact, it consists of many parts that work together in such a way that they produce a specific result and if those parts were wrong by more than a small tolerance it would cease to work. How those parts came to be put together with that small tolerance requires an explanation that is different from the explanation of how a stone in a stream gets to be smooth or something like that.
I’m glad you accept the existence of complexity. I would call the phenomenon of complexity a “fact”, and so would most other people. The reason we call it a fact, rather than a theory is that we are confronted by the phenomenon in a very basic way. I don’t doubt that you could argue that every aspect of or declaration of fact-status is theory-dependant, and that there are an infinite number of turtles supporting the “fact”. However, it is clearly more productive for everyone to accept the basic statement that complexity exists – it is a fact.
My contention, to quote Richard Dawkins, is that there is “the fact of evolution”. I heard him say that during one of his futile debates with a religious maniac. I think what he means, and what I actually mean, is that evolution is (nearly) as basic a phenomenon as complexity, which we are confronted by in all sorts of ways. Perhaps declaration of fact-status is a methodological rule to encourage progress? If so, it is a very useful and well-founded rule!
Now, your definition of “evolution” may be different from what is commonly understood – i.e. the phenomenon of biological evolution. Perhaps you mean a general theory, of which biological evolution could be regarded as an experimental test, or a basic statement, or a deduction or whatever. In which case, we are talking about different things.
Theories and facts talk about different things, yes, but a theory can be factual. Evolution is a theory which we take to be a factual description of certain processes in reality. It is only in taking the untenable view of some religionists, that there is somehow a distinction between a theory and a fact that to do with the theories truth value, that leads to your misundanding Alan Forrester’s quite straightforward statements to you. Evolution is a true theory about how complexity arises; it is also a factual description of some domain of the world. The two previous statements are just two ways of saying the same thing.
> But Newton’s theory was replaced by quantum mechanics and general relativity, which contradict one another so they can’t both be true. We don’t know what the replacement will be and it may be the case that there is stuff physicists have badly misunderstood at the foundations of both theories
Opps .. you made a mistake here by saying that both theories have foundations. The idea that theories have foundations is tied up with justificationist ways of thinking . You know this but still slipped up even when explaining how justificationism is a mistake! Such mistakes are common, and there wouldn’t be a Popperian who hasn’t unintentionally made them. Perhaps by foundations you meant universal ideas, but given how easy it is to be misunderstood I think you should have explicitly said that.
I agree with you. But objectively the foundations of a theory are its axioms, or laws. Some people think that evidence is the foundation of a theory. I think foundations is perfectly legitimate use, but that is because, I guess, I would not confuse the epistemological use, with the logical use. What word would you recomend instead, or would you suggest like a footnote or a parenthetical remark noting the difference?