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Can reason defend itself?

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Can reason defend itself?

Lee Kelly
Ametuer Philosopher

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Posted 08/28/07 - 02:01 PM:	#81
Nonblack Raven, You are mistaken to think that what I have written so far captures my own theory of rationality. I certainly think that competing theories of rationality can be understood as responses to the question: what makes a theory problematic? and it is quite clear that I prefer a form of critical rationalism, or as I call it 'criticalism,' but I have hardly even scratched the surface regarding my own views, which would ultimately detract somewhat from the original problem posed in this thread. Regarding your questions, I think that each can be answered satisfactorily. I wrote this recently, I hope it helps some. Methodological Criticism There is nothing intrinsic about logic which implies that we should seek justification as opposed to criticism, or verification as opposed to falsification, nor demands that we assume every theory submitted for rational appraisal is, by default, problematic. It is a matter of methodology, not logic. The study of rationality i.e. rationology, is primarily a study of rational methods: the set of rules we devise to provide purpose, guidance and standards for rational investigation. It is therefore appropriate to consider what I call 'methodological criticism,' which is a type of criticism not intended to imply falsity. In contrast, if I criticise a theory for logical inconsistencies, or falsification by experiment, I mean to imply that the theory is false. However, if I criticise a theory by methodological standards, I simply mean to imply that to prefer such a theory would be bad rational practice, and not that said theory is false. This kind of criticism is necessary where we are faced by two or more competing theories, which are logically valid and consistent with observations. Of course, the goal of rational investigation is true theories, so methodological criticism is meant to step in when 'falsificational criticism' fails to indicate preference, to that end this type of criticism is often employed to encourage further testing and criticism. The two examples of methodological criticism I wish to consider here, are: check of testability check of problematicality 1. The check of testability is a way of forming a critical preference by favouring those theories which are more highly testable i.e. more falsifiable, corroborable, or improbable. Of course, that doesn't mean it is rational to prefer a more testable theory even if it has been falsified, our goal is true theories, not highly testable theories. It is only when selecting between competing unfalsified theories that testability steps up as important. The reason is simple. The more highly testable a theory is, the more potential events it prohibits, and thus the easier it is to falsify. Moreover, the more potential events a theory prohibits, the better guide to future action, and more informative, it is. Such a rule is it not meant to imply that untestable, or less testable, theories are false; only that we should avoid, where possible, adopting theories which are difficult to test, since if such a theory is mistaken we should find it very difficult to refute it. 2. The check of problematicality is a way of forming critical preference against theories which do not address problems, but may possibly be true. It can be understood very simply as a response to the question: when is a theory in need of revision? and answers it: when a theory is problematic. It is always the case, that for any set of facts, there is an infinite number of potential theories, which are logically valid, equally testable, and consistent with that set of facts, yet are mutually incompatible. However, this need not worry the rationalist, or compel him to revise theories, since the mere possibility that a theory is false is not a criticism of that theory, and if a theory has not been criticised, then it is not problematic, and if a theory is not problematic then it is not in need of revising. To provide one example, we might consider the famous grue problem, where two mutually incompatible theories are both logically valid, and consistent with the evidence. The first theory is 'all emeralds are green,' and the second is 'all emeralds are grue, where grue is defined: green up until time t, and blue after time t.' If we define time t in the future, then both theories are logically valid and consistent with the same evidence. Here we might employ the check of problematicality, and note that the theory 'all emeralds are grue' is inconsistent with many physico-chemical theories regarding the composition of emeralds, behaviour of electromagnetic waves, and structure of the human visual system, theories which were proposed to solve old problems. In this case, the theory "all emeralds are grue" does not criticise any of those theories, it merely expresses and alternative possibility, which we can ultimately wait until time t to test. Edited by Lee Kelly on 08/28/07 - 03:07 PM
"Every man, wherever he goes, is encompassed by a cloud of comforting convictions, which move with him like flies on a summer day." - Bertrand Russell

jwdink
Johnnie

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Posted 08/30/07 - 09:59 AM:	#82
So let me put this as simply as possible, let us suppose we actually have to make a decision. Shall we make it based upon reason, or on—what exactly? If something other than reason, why exactly do you think this is superior to reason? And what is your basis for thinking this? No, I do not think that there are optimal positions. Instead, I subscribe to what, for lack of a better term, I will call incremental rationalism. Given I have to make a decision; I will use the best decision making systems available, as tested by the best means available. What exactly is your alternative that is demonstrably superior? NBR, I have time and time again insisted that there is no "superior" approach, there's just no justification for any particular approach. Whether I choose to quench my thirst by getting some water, or whether I choose to quench it by standing on my head and punching myself in the face, one can't, in the very very strictest sense, justify either as more rational. But we will choose the water approach, because we are innately conditioned towards reasoned choices. Of course, that doesn't mean we won't make some very basic mistakes, especially in psychological experiments designed to mess with our intuitions, it just means that our innate bias is towards reasoned approaches, and this bias is unjustified. This is pragmatically irrelevant. I don't actually think that the sun will stop rising for no reason, or that punching myself in the face is a good way to fix thirst.

Nonblack Raven
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Posted 08/30/07 - 07:07 PM:	#83
jwdink wrote: So let me put this as simply as possible, let us suppose we actually have to make a decision. Shall we make it based upon reason, or on—what exactly? If something other than reason, why exactly do you think this is superior to reason? And what is your basis for thinking this? No, I do not think that there are optimal positions. Instead, I subscribe to what, for lack of a better term, I will call incremental rationalism. Given I have to make a decision; I will use the best decision making systems available, as tested by the best means available. What exactly is your alternative that is demonstrably superior? NBR, I have time and time again insisted that there is no "superior" approach, there's just no justification for any particular approach. Whether I choose to quench my thirst by getting some water, or whether I choose to quench it by standing on my head and punching myself in the face, one can't, in the very very strictest sense, justify either as more rational. But we will choose the water approach, because we are innately conditioned towards reasoned choices. Of course, that doesn't mean we won't make some very basic mistakes, especially in psychological experiments designed to mess with our intuitions, it just means that our innate bias is towards reasoned approaches, and this bias is unjustified. This is pragmatically irrelevant. I don't actually think that the sun will stop rising for no reason, or that punching myself in the face is a good way to fix thirst. You have lost me here. Why exactly do you think it is not more rational to satisfy your thirst by getting a drink of water than by standing on your head and punching yourself in the face? Have you not noted that getting a drink of water has satisfied your thirst in the past and that standing on your head and punching yourself in the face has not? Why exactly do you think that doing something that has established evidence of having worked in the past is no more rational than doing something for which there is not a scintilla of evidence it will work? This is a serious question. Why exactly is past evidence rationally irrelevant? Note, I am not saying that past evidence is a source of certainty--I am asking why all past evidence is "rationally" irrelevant? Now it seems to me, if nothing else, what has worked in the past is a better choice, absent any other information, than what has not? Why do you think the two are rationally equal as decisions? Let me try to explore this in more detail. On the one hand, I might think past experience has some finite probability of being relevant. On the other hand, I might be uncertain about this. But if past experience is irrelevant, than any action whatsoever might achieve what I want, and the set of all actions whatsoever is infinite. Now, why exactly do you think it is rational that there is no finite chance that past experience is relevant, and thus doing anything at all is just as good? This is not a matter of habit, but rather of a rational consideration that there is a finite chance that past experience is relevant, and thus better than doing anything at all. Edited by Nonblack Raven on 08/30/07 - 08:01 PM
NBR

Nonblack Raven
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Posted 08/30/07 - 07:30 PM:	#84
Lee Kirby, We seem to have a bit of a difference, but I cannot quite fathom your position. I suggested that a theory can be rendered problematic by other theories that yield different prediction. You appear to agree, asserting that the problem with grue is: "To provide one example, we might consider the famous grue problem, where two mutually incompatible theories are both logically valid, and consistent with the evidence. The first theory is 'all emeralds are green,' and the second is 'all emeralds are grue, where grue is defined: green up until time t, and blue after time t.' If we define time t in the future, then both theories are logically valid and consistent with the same evidence. Here we might employ the check of problematicality, and note that the theory 'all emeralds are grue' is inconsistent with many physico-chemical theories regarding the composition of emeralds, behaviour of electromagnetic waves, and structure of the human visual system, theories which were proposed to solve old problems. In this case, the theory "all emeralds are grue" does not criticise any of those theories, it merely expresses and alternative possibility, which we can ultimately wait until time t to test." So are you saying that all emeralds are grue is problematic not because it differs with the theory that all emeralds are green, or because it differs with other physica-chimcial theories (all of which are subject to grueification-- eg. the structure of the human visual system was such as to find emeralds green before time t, and grue after time t, etc.) After all, what I asserted was not gure, but the existence of a theory P which implied not Q, and a theory Q which implied not P would render both theory P and theory Q problematic. Do you agree or disagree? Doe it depend on the nature of P and Q, and, if so, how? Or are you saying nothing can be said about grue versus green before time t. Both have problems, but either way, you either seem to be saying thoeries can render other theories problematic--exactly what I asserted; or they cannot, which leads directly to my assertions about the uselessness of problematicity for decision making purposes. Choose and we can have a discussion, assert both and I am not sure what to say. Sorry to be so confused as to exactly what you are asserting. added on edit: You assert: "1. The check of testability is a way of forming a critical preference by favouring those theories which are more highly testable i.e. more falsifiable, corroborable, or improbable. Of course, that doesn't mean it is rational to prefer a more testable theory even if it has been falsified, our goal is true theories, not highly testable theories. It is only when selecting between competing unfalsified theories that testability steps up as important. The reason is simple. The more highly testable a theory is, the more potential events it prohibits, and thus the easier it is to falsify. Moreover, the more potential events a theory prohibits, the better guide to future action, and more informative, it is. Such a rule is it not meant to imply that untestable, or less testable, theories are false; only that we should avoid, where possible, adopting theories which are difficult to test, since if such a theory is mistaken we should find it very difficult to refute it." I find this kind of stuff disturbingly vague. Consider hypotheses H, A is always greater than B. Consider H', in a certain very narrow context, A is exactly equal to the square root of C. Suppose neither H or H' has been refuted across many tests. Now, in my very practical world, I need may need to decide whether to use H'. Is H' to be rejected because it rejects fewer potential events than H? Accepted because for the events covered it is more precise than H? Or accepted for reasons you do not offer at all, H' is the best theory for the very narrow context, and H is the best for a broader context? Edited by Nonblack Raven on 08/30/07 - 07:41 PM
NBR

jwdink
Johnnie

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Posted 08/31/07 - 07:15 AM:	#85
Nonblack Raven wrote: You have lost me here. Why exactly do you think it is not more rational to satisfy your thirst by getting a drink of water than by standing on your head and punching yourself in the face? Have you not noted that getting a drink of water has satisfied your thirst in the past and that standing on your head and punching yourself in the face has not? Why exactly do you think that doing something that has established evidence of having worked in the past is no more rational than doing something for which there is not a scintilla of evidence it will work? This is a serious question. Why exactly is past evidence rationally irrelevant? Note, I am not saying that past evidence is a source of certainty--I am asking why all past evidence is "rationally" irrelevant? Now it seems to me, if nothing else, what has worked in the past is a better choice, absent any other information, than what has not? Why do you think the two are rationally equal as decisions? Let me try to explore this in more detail. On the one hand, I might think past experience has some finite probability of being relevant. On the other hand, I might be uncertain about this. But if past experience is irrelevant, than any action whatsoever might achieve what I want, and the set of all actions whatsoever is infinite. Now, why exactly do you think it is rational that there is no finite chance that past experience is relevant, and thus doing anything at all is just as good? This is not a matter of habit, but rather of a rational consideration that there is a finite chance that past experience is relevant, and thus better than doing anything at all. I use the Humean argument about causation to approach this. We can't prove that the tendency of things to be consistent will remain consistent. That is, we cannot rationally back up our belief that things will happen as we expect them to. Inductive inference operates on the principle that the past acts as a reliable guide to the future (sometimes called the principle of the uniformity of nature). For example, if in the past the sun has risen in the east and set in the west, then, inductive inference suggests that it will probably rise in the east and set in the west in the future. But how are we to explain our ability to make such an inference? Hume argued that we cannot explain our capacity as a product of our faculty of reason. For reason could only come in two flavours, and neither of these can be used to ground our inferences. 1. Demonstrative or Intuitive. This sort of reasoning is basically a priori. We cannot determine a priori that the future will be conformable to the past, because it is both (logically) consistent and conceivable that the world stop being uniform. Hume here does not distinguish adequately between the uniformity of nature in general and the persistence of particular regularities. For it is open to a philosopher (perhaps of a Kantian bent) to argue that it is in fact inconceivable that the world not be regular in some ways. However, what is important, and what vindicates Hume, is that for any particular regularity in the operations of nature, it is consistent and conceivable that it might cease. Thus we cannot ground our inductions in a priori reasoning. 2. Inductive. We cannot appeal, either, to our past successes in using inductive inference, to the fact that it has worked in the past, for this would be circular reasoning. Hume thus concludes that our inductive practices have no rational foundation, for no form of reason will certify it.

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