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Question about Popper's critical rationalism
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Atrytone
Graduate Usergroup: Members Joined: Sep 18, 2004 Location: Portland, Oregon Total Topics: 6 Total Posts: 188 |
Posted Oct 11, 2008 - 2:41 PM:
Subject: Question about Popper's critical rationalism Someone pointed out to me today that my epistemology is similar to Popper's critical rationalism. I'd heard of Popper, but hadn't read him, and I'm just starting to look into his epistemology. If time allows I'll probably want to read his work, but so far I've just glanced at the Wikipedia article on critical rationalism. It does indeed sound close to my ideas, but what's up with the bit about preferring the least probable theory that hasn't been falsified? Why does Popper think less probable theories are better? Can anyone give me a brief explanation to get me started? Thanks! |
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unenlightened
modern poster Usergroup: Administrators Joined: Aug 10, 2007 Location: Wales Total Topics: 47 Total Posts: 4726
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Posted Oct 11, 2008 - 3:48 PM:
I think you can safely take that as a misprint for least improbable theory that hasn't been falsified. In one sentence he says that scientific theories are never proved to be true and that a sound theory is one that can in principle be proved false - as distinct from (famously) Freudian theory, for example, which can explain anything whatsoever, and therefore says nothing. ...most of our actions are the result of the past, or according to a future ideal. That's not action, that is just conformity. J Krishnamurti "Philosophy, to the Philistine, is an evolutionary process, watched over by some sort of brisk dynamic Providence, and culminating in the supreme insight of modern thought." John Cowper Powys |
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Banno
the One-Line Wonder! Usergroup: Sponsors Joined: Aug 15, 2004 Location: Oz Total Topics: 180 Total Posts: 9672
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Posted Oct 11, 2008 - 4:01 PM:
unenlightened wrote: I think you can safely take that as a misprint for least improbable theory that hasn't been falsified. No, the article is correct. The least probable theory is easier to falsify, and so is to be preferred. And does not my art show that you have brought forth wind, and that the offspring of your brain are not worth bringing up? |
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sqeecoo
Assistant Professor Usergroup: Members Joined: Oct 05, 2007 Total Topics: 2 Total Posts: 375 |
Posted Oct 11, 2008 - 4:32 PM:
Hi! First of all, you should be careful of what philosophers say about Popper. Almost no-one likes him, and everyone criticizes him. This is great, but unfortunately some of the criticism misunderstands his position, or ignores what he says in anticipation of that exact criticism in the very same book that's being criticized. Which does not, of course, mean that you should reject any criticism of him, but that it's usually good to check it against his actual texts. A great resource is here: http://www.geocities.com/criticalrationalist/ The page includes some of his own articles. I recommend this one as a start: http://cla.calpoly.edu/~fotoole/321.1/popper.html I must say he is my favorite philosopher. His epistemology is powerful, simple, and very no-nonsense, as is his style of writing. He also applies his epistemology to huge variety of things from politics to the mind-body problem. Another guy to look at is David Miller. A lot of his articles can be found here: http://www2.warwick.ac.uk/fac/soc/philosophy/staff/miller/ He is Popper's "pupil", and Miller is more or less the only guy that can be trusted not to misrepresent his position when he says "Popper said X". This is just speaking from experience, I've read almost all of Popper's works and also a lot of criticism and summaries of, and the latter usually have some mistakes - Miller's don't. (For instance, Stephen Hawking calls Popper a "positivist" in one of his books, which is like calling Coleridge a neo-classisist - and this is just a labeling mistake, usually they are more serious, though more complicated, so I chose this one as an example) Popper's works are generally more interesting and easier to read, but Miller is the place to go if you want direct replies and discussion on modern topics - Miller uses very modern terminology and addresses all the latest criticism directly. His book "Critical Rationalism, A Restatement and Defense" is especially good. He also clears up the position of critical rationalism in comparison to skepticism, relativism, and various forms of "justificationalism". This is a good article in that vein, and one I also recommend: http://www2.warwick.ac.uk/fac/soc/...staff/miller/wroclaw2a.pdf Ok. Sorry to be so long winded, I just wanted to point you in the right direction if you want to do some further reading. I certainly suggest it. If nothing else then to read someone clearly expound interesting ideas similar to your own that you needn't agree with - in fact, he says you shouldn't before trying to criticize them! Anyway, to answer your question. The point is that, purely logically speaking, a theory that *says more* is less probable than one that says less. This is due to it having more content, i.e. applying to more cases. In other words, if we are aiming for high probability of truth, we would make our theories as conservative as possible, and have them say as little as possible. Popper says we shouldn't do this, but instead make our theories as bold and improbable as possible, which makes them both more interesting and easier to test. Mind you, we are talking about the logical probability of a theory, that diminishes with the increase in number of cases the theory can be applied to. To give a practical example: People start dying, after turning green and suffocating. Someone who is concerned with high probability will prefer the theory "Whenever someone starts turning green, they will probably die" to the theory "Some kind of algae in the air are settling on the lungs and skin and causing suffocation". But while the latter is not necessarily true, and is logically less probable since it claims more, it's more interesting and fairly easily testable. All this is basically brought up as a by-product of him saying that testing and criticism, not verification, is the best method of science/rational inquiry. There, I hope that's a satisfactory answer. But if it isn't, by all means criticize, and I'll try to reply! ![]() EDIT: Ok, I think I went a bit overboard on the "trust no one!" bit. That wikipedia articles is excellent. However, if you had gone to the Stanford Encyclopedia of Philosophy, usually an excellent source and certainly a more "serious" one, you'd have found some very dubious and/or misleading bits in their article on Popper. I had a lot of experiences like that (try this horrible article http://www.libertarian.co.uk/lapubs/philn/philn065.htm), so I wanted to warn you before you read something incorrect and never had any reason to double-check it ![]() Basically, only Miller and Popper (and Bartley, to an extent) are fully reliable sources on what critical rationalism, as introduced by Popper, actually says. And all criticism should be taken seriously, but checked against Popper's and Miller's works directly. I haven't yet found criticism that they haven't replied to, and quite well at that. Edited by sqeecoo on Oct 11, 2008 - 5:11 PM |
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unenlightened
modern poster Usergroup: Administrators Joined: Aug 10, 2007 Location: Wales Total Topics: 47 Total Posts: 4726
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Posted Oct 11, 2008 - 4:36 PM:
That makes no sense to me at all. Your average conspiracy theory for example is hard to falsify, but highly improbable and not 'to be preferred' at least by me. edit: ah, thanks for that sqeecoo - now I understand. Objection withdrawn mea culpa and all that. Edited by unenlightened on Oct 11, 2008 - 4:41 PM ...most of our actions are the result of the past, or according to a future ideal. That's not action, that is just conformity. J Krishnamurti "Philosophy, to the Philistine, is an evolutionary process, watched over by some sort of brisk dynamic Providence, and culminating in the supreme insight of modern thought." John Cowper Powys |
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sqeecoo
Assistant Professor Usergroup: Members Joined: Oct 05, 2007 Total Topics: 2 Total Posts: 375 |
Posted Oct 11, 2008 - 4:44 PM:
This is not about probability in relation to evidence (evidence can't raise the probability of a theory over 0 anyway), but about *logical* probability, probability in relation to content. Basically, a theory that says more and is better testable and more interesting. But this also means that because it says more, it is thus less probable. Read my example and see if you are satisfied. If not, we can go into it in more detail ![]() EDIT: Glad to have helped, unenlightened. But this is something that it was more than reasonable to ask clarification for, since it's surprising and not explained in detail or especially clearly in the article. So no culpa at all on your part, in my opinion
Edited by sqeecoo on Oct 11, 2008 - 5:30 PM |
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Atrytone
Graduate Usergroup: Members Joined: Sep 18, 2004 Location: Portland, Oregon Total Topics: 6 Total Posts: 188 |
Posted Oct 11, 2008 - 6:43 PM:
No worries about being long-winded, squeecoo. That was very helpful, and just what I was looking for. I'll have to look over some of those articles you recommended and chew on it all a bit, but I understand much better now what he's trying to get at by preferring theories that have a lower logical probability. Thanks a bunch! |
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tormeyg
Graduate Usergroup: Members Joined: Aug 22, 2008 Total Topics: 3 Total Posts: 115 |
Posted Oct 11, 2008 - 7:31 PM:
Atrytone wrote: Someone pointed out to me today that my epistemology is similar to Popper's critical rationalism. I'd heard of Popper, but hadn't read him, and I'm just starting to look into his epistemology. If time allows I'll probably want to read his work, but so far I've just glanced at the Wikipedia article on critical rationalism. It does indeed sound close to my ideas, but what's up with the bit about preferring the least probable theory that hasn't been falsified? Why does Popper think less probable theories are better? Can anyone give me a brief explanation to get me started? Thanks! As one of the poster's stated Popper is routinely misunderstood. His approach to epistemology in science is in strak opposition to that of logical positivists and to those who use Inductive reasoning and probabilities to identify "truth" or knowledge. I put truth in quotations because I refer to it in a broader ontological sense. The issue with preferring the "least probable theory that withstands falsifcation" is based on process of scientific verification. In sceince and especially physics, there are always several different theories that can explain the same phenomena or empirical results. The issue as to which theory becomes 'accepted" or predominant is based on many factors that sometimes are difficult to articulate. Generally we like the theory that postulates the least, or makes the least amount of assumptions, and we prefer the theory that is the most compact or succinct.(both are related of course) So Popper is making an observation, that when we have competing theories that currently agree with empirical data, it is best to choose the least likely one, or the one which makes the most improbable or unique predictions, therefore, it will be easier to "falsify" or verify the theory. Also, making probability assumptions trelies on Inductive reasoning, which of course is prohibited in logic and philosophy. Thus, those theories or hypotheses which appear most 'probable" are probably not true since their "probability" relies on faulty reasoning, namely Induction. Take for example the statement, "All swans are white". Based on empirical data that is fairly probably true, yet its truth value doesn't reveal anything about nature that is fundamental or unique. However, the claim "some swans are black" is improbable, yet if true, would reveal some unique physical phenomenon. Take Einstein's relativity when it was first introduced. There were other theories which explained the data that was available but required one to still postulate the ether. Einstein turned the tables, and postulated that light was the same velocity for all observers, which was highly improbable, yet was fairly easy to falsify and would require the least amount of physical assumptions. So hbis theory was the less probable since its assumptions were unique or different, yet it agreed with all the current data and ended up making new unique predictions. So again, the least probable theory at the time, is the one which makes the most unique assumptions and distinctive physical predictions. If one looks at most successful physical theories, whther relativity or quantum mechanics, one sees that at the time with the available data, those were among the elast probable explanations of the data. Indeed, that is what makes a truth true. In deduction unlike induction, a conclusion or theorem or true statement "must necessarily follow from the axioms while in induction it "may" simply follow. Well, clearly the former would be less likely or more improbale than the latter when compared side by side. I hope that was helpful. |
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sqeecoo
Assistant Professor Usergroup: Members Joined: Oct 05, 2007 Total Topics: 2 Total Posts: 375 |
Posted Oct 12, 2008 - 3:20 AM:
Actually, no number of white swans can raise the probability of the theory "all swans are white" over 0. This is because the theory basically says - any thing, at any time and anywhere, if it's a swan, it's not non-white. Thus, as an universal statement, it applies to an infinite number of cases. Any finite number of confirmations is still infinitely small compared to infinity ![]() (this is one of popper's main arguments against induction) But when he says we should prefer the least probable theory, Popper is talking about logical probability, namely probability in relation to content, and not subjective probability (probability with regards to evidence *we* have) or objective probability (the propensity or tendency of an event to occur). I agree with the rest of what you said though
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tormeyg
Graduate Usergroup: Members Joined: Aug 22, 2008 Total Topics: 3 Total Posts: 115 |
Posted Oct 13, 2008 - 8:09 PM:
sqeecoo wrote: Actually, no number of white swans can raise the probability of the theory "all swans are white" over 0. This is because the theory basically says - any thing, at any time and anywhere, if it's a swan, it's not non-white. Thus, as an universal statement, it applies to an infinite number of cases. Any finite number of confirmations is still infinitely small compared to infinity ![]() (this is one of popper's main arguments against induction) But when he says we should prefer the least probable theory, Popper is talking about logical probability, namely probability in relation to content, and not subjective probability (probability with regards to evidence *we* have) or objective probability (the propensity or tendency of an event to occur). I agree with the rest of what you said though ![]() Thanks for the critique. I was actually using the "all swans are white" as a counter-example. But I think your analysis of the statement is a little questionable. "all swans are white" is making a universal statement. And the reason its considered "highly probable" as an empirical statement is that presumably, all swans ever observed were white. So, the empirical prediction, isn't making a unique or distimctive claim, and I think that was part of what Popper was getting at. If a physical theory cannot make empirical predictions that make unique or distinctive or new or "improbable" claims that can in principle be falsified, than that theory lacks descriptive and ontological value. The issue of how we define probable in this context, I think, is simpy in terms of available or conventional empirical data, which of course is an inductive judgement. And when you say probability in terms of logical probability, or content, I think that may be somewhat paradoxical in a Popperian scheme. Why? Because popper was claiming that in logic, a statement is either true or false, there is no gradation because in deduction, a theoem is necessarily true. If one acknowledges logical probability in he manner you suggest, one is already committing to an inductive reasoning in order to value logical statements which I think popper would disagree with. On the other hand, the "probability" I was attempting to define, was an empirical or subjective one that is based on the empirical descriptions or statements that a prospective theory could generate. That is why Popper suggests appealing to the least probable (in the empirical sense mentioned above), as a rule of thumb, since the theory that initially makes the most improbable physical claims, will if verified, be the most physically descriptive and empirically powerful. So in the end, I think in this context, Popper was referring to what I call empirical or subjective probability regarding the theories' empirical claims. I am confident he was not referring to logical probability in the sense of truth value, since that would be a paradox to Popper. The logical truth of a theory is limited to its mathematical or logical reasoning, which of course, is void of any empirical data since that is inductive. Thus it has only two probability values 1 or 0. Take Einsteinian Relativity, it made phsyical claims that at the time, were highly improbable based on our collective empirical data and sensical intuitions. However, the mathematical reasoning was 100% logically true, since it could only be false or true, or valid or invalid logically. It was the empirical claims that served to buttress the physical axioms or postulates of theory, that is it was able to withstand falsification so far. And the more radical or "improbable" the empirical claims of the theory, in this case curved spacetime, constant light speed etc, the greater the theories' value and power because the greater it descriptive power. |
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