News

Loading...

Tuesday, September 20, 2005

Induction

Wittgenstein writes in On Certainty:

"And it would be just the same if the pupil cast doubt on the uniformity of nature, that is to say on the justification of inductive arguments. - The teacher would feel that this was only holding them up, that this way the pupil would only get stuck and make no progress. - And he would be right. It would be as if someone were looking for some object in a room; he opens a drawer and doesn't see it there; then he closes it again, waits, and opens it once more to see if perhaps it isn't there now, and keeps on like that. He has not learned to look for things.

"But imagine people who were never quite certain of these things, but said that they were very probably so, and that it did not pay to doubt them. Such a person, then, would say in my situation: "It is extremely unlikely that I have ever been on the moon", etc., etc. How would the life of these people differ from ours? For there are people who say that it is merely extremely probable that water over a fire will boil and not freeze, and that therefore strictly speaking what we consider impossible is only improbable. What difference does this make in their lives? Isn't it just that they talk rather more about certain things that the rest of us?"

And that is essentially the position of the Popperians: they use induction just like the rest of us do, but they simply insist on talking about it in an obscure and convoluted fashion.

9 comments:

  1. Anonymous9:48 AM

    "And it would be just the same if the pupil cast doubt on the uniformity of nature, that is to say on the justification of inductive arguments. - The teacher would feel that this was only holding them up, that this way the pupil would only get stuck and make no progress. - And he would be right. It would be as if someone were looking for some object in a room; he opens a drawer and doesn't see it there; then he closes it again, waits, and opens it once more to see if perhaps it isn't there now, and keeps on like that."

    On the contrary, falsificationists refute its presence in the drawer and look elsewhere. But inductivists need to keep 'supporting' the view that the drawer is empty by repeatedly looking.

    ReplyDelete
  2. But why do you think that not seeing something in the drawer now means it won't be there in a minute? Perhaps because, in the past, you've repeatedly seen that objects don't suddenly appear in drawers, and you've made the inductive inference that objects don't suddenly appear in drawers?

    All you are able to "falsify" is the proposition that the object was in the drawer at the moment you looked. To go beyond that, you need induction.

    ReplyDelete
  3. But how will induction tell you that the object won't be in the drawer in the future, just because it is not in the drawer now?

    ReplyDelete
  4. Of course, it doesn't guarantee that! But from seeing it again and again, we begin to suspect a regularity at work -- non-living objects don't just wander around on their own.

    The two complaints directed at this form of reasoning are:
    1) It's not deductively valid.
    2) There is no grounding for it.

    The answers:
    1) Well, yes, that's why it's called induction, not deduction!
    2) There is no grounding for deduction, either.

    ReplyDelete
  5. "But from seeing it again and again, we begin to suspect a regularity at work -- non-living objects don't just wander around on their own."

    Surely we to go from a theory of the inanimateness of stones; to a prediction that the stone won't move - not the other way around?!

    ReplyDelete
  6. Julius, how did we arrive at a theory that stones are inanimate besides seeing them laying around like rocks all the time? And if we saw them doing the rumba, wouldn't we reconsider our theory?

    ReplyDelete
  7. Anonymous5:06 AM

    "how did we arrive at a theory that stones are inanimate besides seeing them laying around like rocks all the time?"

    By conjecture. It is not possible to observe all stones.

    "if we saw them doing the rumba, wouldn't we reconsider our theory?"

    If we saw even one doing the rumba then the theory [that all rocks are inanimate] would be refuted. That we might see one cannot be ruled out a priori.

    Where does 'induction' come into the picture?

    ReplyDelete
  8. Anonymous5:20 AM

    Gene:

    "But from seeing it again and again, we begin to suspect a regularity at work -- non-living objects don't just wander around on their own."

    How is this not just a guess? Suspecting that objects don't wander about on their own is nothing but conjecture. It may very well be true but epistemologically it is nothing but conjecture. Observing one move though is refutation of our conjecture.

    And that is essentially the position of the 'inductivists': they use conjecture just like the rest of us do, but they simply insist on talking about it in an obscure and convoluted fashion.

    ReplyDelete
  9. Yes, of course it is conjectural!

    And the 400-year-old name for conjectures arrived at by observing the repeated occurence of some type of event is induction. Go back to Bacon and Boyle -- they never claimed that induction yields infallible knowledge.

    ReplyDelete