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You seem to be of the opinion that absence of absolute predictability is equivalent to absolute absence of predictability.

Posted by: Floyd ( Darwin Fan Club, Cascadia Libre! ) on January 23, 19100 at 11:45:50:

In Reply to: Sir Karl Popper ( for Gideon et al) posted by Piper on January 19, 19100 at 23:55:13:

[snip eloquent description]

: PROBLEMS FOR SIR KARL
: The central objection to be raised against Popper is that his theory of science accounts only for negative knowledge. He provides no way to show a theory is true and hence there is no way to gain positive knowledge.

There remains a way to refute the false. This makes what is left over (that which has not been falsified) that much more likely. Admittedly, "knowledge" as such, is probablistic, rather than absolute, and the curve of knowledge is asymptotic, but 99% certain is still superior to 50% certain.

: But positive knowledge is supposed to follow from induction (THIS is the important distinction between induction and deduction, induction priovides us with new knowledge about the world). Indeed it is this positive knowledge that makes induction important. Our ability to send people to the moon, to make computers, etc is because we *know* that certain causes have certain results.

I assume you highlighted *know* because you recognize that this knowledge is contingent and probablistic, and is open to revision in the event of further information coming to light.

:Popper does not explain how we might know 'All As are Bs' just that it is false that 'All As are Bs' thus he fails to deal properly with the problem of induction.

: Essentially the problem of induction is how we can base judgments about the future on evidence about the past. To say that scientific theories are just conjectures is to say that we have no rational basis for believing their predictions.

This is true, but misleading. Popperian science doesn't say that theories are just conjectures. It says that theories are constructs of units and the proposed relationships between those units which, together, can be used to generate testable predictions. Theories, themselves, remain untestable (directly, in any case) because they have no empirical component (i.e. they are mental constructs about the world, and ideas can't be tested). Hypotheses that are generated, based on theories, can be tested and falsified. Consistent failure to falsify the hypotheses generated by a theory tends to support the validity of the theory. Consistent success at falsifying the predictions of a theory does successfully falsify the theory however. The removal of that which is false increases the likelihood that that which remains is true.

: i.e. Popper denies we can make rational judgments about the future.
: -Consider: A) I jump out of a plane without my oarachute and i shall fall to my death
: B) When i jump out of the plane without my parachute i shall fly like a bird.

: Clearly it is more rational to believe A), which assumes future like past. But as Popper rejects induction he holds that past evidence does not makes beliefs about the future more rational than any others and thus B is no less rational than A.

Again, slightly misleading example. Recognizing that all predictions are inherently statements of probability is not the same as asserting that there is no basis for choosing between two alternatives. The fact that it is less than 100% certain that a parachute will work does not make it equally rational to jump without one.

: But of course believing A is more rational than believing B (this is why induction is a problem). Problem is to showe why beleiving A is more rational than believing B when induction is not logically compelling. Popper's denial of rational superiority of A over B connotes his failure to recognise that there is in fact a problem with induction.

You seem to be of the opinion that absence of absolute predictability is equivalent to absolute absence of predictability. I suspect that this is a false equation.
-Floyd



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