• apokrisis
    Choose any point you like as the origin, choose any units you like. They can be translated into metric or imperial or cubits or whatever.Banno

    Sure. If you have a theory of abstract reference frames then you can add the further constraint that it’s distances are ruled off in terms of some arbitrary unit. But so far you haven’t shown how that mental construct relates to someone’s world as a useful fact.

    As I say, the aboriginal form of life is said to want to think about spatial distance in terms of duration of effort. The Aussie education system is suppose to recognise that cultural difference in its attempts to teach basic mathematical concepts in a way that don’t continue to favour the later white settlers.

    So is a reply not in metres, or any equivalent notion of counting a unit of distance, going to get marked wrong by you? Does everyone have to conform to your Cartesian conception of reality?

    Speak clearly now. You have probably used up your last chance.
  • Janus
    I could accept abduction as creating hypotheses. But if so, i don't see any advantage in using the term abduction. Why not just talk about creativity? Is it only to place it in the Peircian holy trinity with deduction and induction? Then forget it.Banno

    For me it fits because there seem to be basically three modes of being led in thought.

    The etymology for 'deduce' is "lead down, derive" (in Medieval Latin, "infer logically"), from de- "down" (see de-) + ducere "to lead," from PIE root *deuk- "to lead." ; which seems appropriate since a deduction is an abstracted form of thought.

    The etymology for 'induce' is "to lead by persuasions or other influences," from Latin inducere "lead into, bring in, introduce, conduct; persuade; suppose, imagine,"

    The etymology for 'abduce' is "to draw away" by persuasion or argument, 1530s, from Latin abductus, past participle of abducere "to lead away, take away," also in figurative senses, from ab "off, away from" (see ab-) + ducere "to lead," from PIE root *deuk- "to lead." Related: Abduced; abducing.

    The prefixes 'ab' 'in' and 'de' seem to give clues to the character of each mode.

    'De' is "Latin adverb and preposition of separation in space, meaning "down from, off, away from," and figuratively "concerning, by reason of, according to;"

    'In' is an "element meaning "into, in, on, upon""

    'Ab' is a "word-forming element meaning "away, from, from off, down," denoting disjunction, separation, departure; from Latin ab (prep.) "off, away from" in reference to space or distance, also of time"

    Etymological source: The Online Etymology Dictionary

    And I continue to fail to see how an invalid induction can be used as a justification. Consider an alternative - coherentism, for example. A belief is justified if it coheres with our other beliefs. Isn't that a superior account of justification than an invalid half-argument such as {f(a), f(b), therefor (x)f(x)}?

    A belief "cohering with other beliefs' just is validation by abduction and induction as well as deduction, when you think about it. I think the problem is that you are looking at induction as Hume did, as something that somehow must rely on immediate perception or else amount to nothing. It relies rather on cumulative perception. Humans have always posited causes for observed events, different types of causes for different types of events, and at least since the Enlightenment a nature which consists in a unified concatenation of causes (laws and forces). This is what has evolved into science considered as a whole interrelated system of understanding. All of this has been arrived at by inductive (observational), abductive (speculative) and deductive (logical; for the parts contributed by mathematics and geometry) reasonings. It is that scientific (in the broadest possible sense) body of understanding that determines what is considered plausible; i'e' what "coheres with other beliefs", I would say.
  • Janus
    LOL. But Banno covered that already.... "How we measure that, from base or sea level or your nose or whatever - is up to us."apokrisis

    Ha ha, looks like I was just being pedantic then, wanting to say that the height of the Rock would normally be thought of as its height from the surrounding desert.

    I'm not sure what Banno has in mind; but in general I would agree that some mountains do project up more from the Surface than others, regardless of whether anything has been measured or where you are looking from and so on.

    I had a similar argument with Wayfarer once about one pair of things being closer to each other, than another pair. He wanted to claim that it was a matter of perspective, but I think he was thinking about whether they looked closer or not. Even then, I don't follow Nagel in thinking the "view from nowhere" is unattainable. It is if you think it is truly a view from no perspective at all, but when you realize it is actually a view from no particular perspective, which means from every perspective, then it becomes apparent that it is not incoherent and is, at least in principle, attainable, even if not absolutely attainable (whatever that could mean).
  • Banno

    That's more or less it.

    The extension of the view from somewhere is not the view from nowhere, but the view from anywhere.

    We find it by talking to each other.
  • Banno
    A belief "cohering with other beliefs' just is validation by abduction and induction as well as deduction, when you think about it.Janus

    I can't find much here to disagree with you on.

    There remains a special place for deduction. If one has true premises and a valid argument then the truth of the conclusion must follow. This is not the case with induction and abduction (the word puts me in mind of alien experiments...)

    If one grants abduction and induction, then their place can only be in justifying belief, not in finding truth. Unless one follows @apokrisis in rejecting truth altogether.
  • Janus
    If one grants abduction and induction, then their place can only be in justifying belief, not in finding truth.Banno

    Yes, I think that's right. Science does not give us truth but speculative understanding. Truth (in the propositional sense, at least) is a rather pedestrian affair to do with official facts and figures, and the obtaining of states of affairs.
  • apokrisis
    It is if you think it is truly a view from no perspective at all, but when you realize it is actually a view from no particular perspective, which means from every perspective, then it becomes apparent that it is not incoherent and is, at least in principle, attainable, even if not absolutely attainable (whatever that could mean).Janus

    Yep. It is an interesting exercise to imagine seeing any object from every perspective possible. So Ayers Rock from the inside, from every distance outside, then over all timescales as well. Any notion of its substantial being would become dissolved in some truly panscopic view that built in no preference.

    And then contrast that with the kind of scientific view we aim for where we instead see Ayers Rock in terms of natural laws and initial conditions. More like a wire frame computer simulation.
  • apokrisis
    If one grants abduction and induction, then their place can only be in justifying belief, not in finding truth. Unless one follows apokrisis in rejecting truth altogether.Banno

    Don’t be such a sook. If you agree with Janus, you agree with me. Get over it.
  • Banno

    Ok, then - let's go back a few steps. Picture Newton universalising gravity, apples and all.

    Was that an act of induction? Can you explain how?
  • Janus

    Led by repeated observations of objects invariably falling to Earth and the rising of Sun, moon and planets, to believe that such events will always happen (induction) he imagines that there is a natural law that determines these events, and in a further leap of imagination (abduction) he thinks that these seemingly very different events may be manifestations of a single law or force.

    If this thought process is not essentially deductive (even it can, although not exhaustively, be framed in deductive form) then what would you say it could be other than inductive and/ or abductive?

    I would say that it is inductive in the sense that experience naturally induces us to think that way, and abductive in that our imaginations abduce (which means they lead us away) from concrete instances to generalities and analogies. It's like the abductive thought I mentioned before that if spacetime is curved then it might be expected, analogously to curved glass and other transparent materials, to refract light. I mean this thought is not deductive in the sense that curvature of spacetime logically entails that light will be refracted. So the observed refraction of light does not prove that spacetime is curved.

    Perhaps you could give an account of your thoughts on these specific examples.
  • Janus

    Cool, it's a very interesting thought experiment. From any possible viewpoint it would still be larger (and more enduring and endurant) than an apple, though, it seems.

    Yes, it's hard to imagine Uluru slowly emerging out of some very different milieu, and where in that process we would locate the "initial conditions".
  • Banno
    Have a look a the wiki article.

    It is hard to find in that description events that take the inductive form. So again I suggest that induction is a post hoc account. As such I do not agree that it takes a centra place in science.
  • Janus

    What exactly do you mean "events that take the inductive form" and which description are you referring to?

    I would say that all accounts of human activities and thought processes are "post hoc" so I'm not sure what point you are trying to make in pointing that out in this particular case.

    Apparently Newton thought he was doing inductive reasoning. From the Wiki article you linked:

    "This is a general physical law derived from empirical observations by what Isaac Newton called inductive reasoning."
  • apokrisis
    It is hard to find in that description events that take the inductive form. So again I suggest that induction is a post hoc account. As such I do not agree that it takes a centra place in science.Banno

    So does that account instead describe deduction as being central to the development of the thinking involved? I think not.

    Newton's theory of universal gravitation has of course become a classic test case for philosophy of science. Newton himself rejected a simple hypothetico-deductive model in favour of "the Newtonian style" which endorsed an abductive approach able to take the leap from complex particulars to simple generalities.

    Inference to the best explanation involves a back and forth where the world as it is seen, and the laws that might explain that, swim into view together as the two halves a modelling relation. So the particular is extrapolated to discover some general - motivated by the reasonable metaphysical principle that lawful simplicity underlies all the messy real world complexity. And then the truth of that generality is checked against what it then predicts. It is tested by whether it seems to predict the particulars that were used to predict it.

    So abduction is a mix of the inductive and deductive - but at a still vague level. All it needs is the start of what feels like it is going to become a good fit. Things are starting to snap together. A pattern is beginning to emerge.

    You can try to formalise abduction as an if-then habit of thought. It is a species of induction in attempting the "invalid" thing of going from the particular to the general. And it is also "invalid" in that it accepts vagueness as a suitable grounding. Nothing actually has to be crisply or definitely stated at the beginning. That is instead the desired destination. Meanwhile a loose fit is good enough if it is a fit that seems to be growing tighter as work is done to clarify the direction being revealed.

    Anyway, it is if-then reasoning. If this general rule were the case, these kinds of particular results would not look surprising. These kinds of particular results do exist. Therefore the general rule is probably the case. And historians show that this is the way Newton moved in his reasoning to develop a mathematically-definite theory.

    So all reasoning involves this two-way interaction. We need to go from the particular to the general, and from the general to the particular, in as secure a way as possible. Obviously, deduction is more secure than induction because it introduces no new semantics. But then the cost of that is that deduction can introduce no new semantics.

    Then the sense that this is a real jump, not some gradual change, is explained by the complex world of messy particulars being the state of broken symmetry in nature. And what we are trying to recover - as the trick that makes scientific models work - is the deeper symmetry that got broke.

    We have a smashed up lot of glass bits on the floor. And a lot of bits are probably missing. We theb want to know whether it was once a glass vase or a glass dish, or whatever.

    So the move from the particular to the general is seeking a hidden symmetry that is believed to lurk behind a messy complexity. We can't see that symmetry directly as a further thing to observe - symmetry-breakings tend to be thermally irreversible and so the past is gone. But we can imagine it mathematically. We can recover it as a mathematical idea.

    Any amount of observables can't add up inductively to reveal the hidden whole. What's broke is broke when it comes to our available view of reality. But we can leap imaginatively to the kind of symmetry that could be broken to yield the kind of fragments we see all around.

    So reasoning itself is an irreducible coupling of the inductive and deductive directions of thought. And then abduction goes to the fact that this self-organising loop has to start off as a seed and then grow into full and definite flower.

    Abduction has both flavours of thought coupled together - as it must to be capable of growth towards a definite understanding. But it is that possibly successful thought still in its tentative stage - one where a loose fit is still acceptable. We are in a state of mind where we are allowing ourselves to be guided by some general principles - like that simple symmetries lie behind every messy and complex broken symmetry - and then looking backwards retroductively to see what generalisation can in fact predict the particulars we seem to identify as being suggestive or significant.

    The peculiarity of an elliptical orbit could be explained if it were composed of an inertial straightline motion coupled to a centripetal accelerative force. The inertia is a symmetry, so falls out of the story. You now just have to account for the symmetry breaking which is the centripetal force exerted by a planetary body.

    But why should only planets have gravity? Right, let's again find the symmetry. All masses attract. It is not something special but something which is the same for all. The symmetry of the force is broken only by the accident of the locally differing quantities of mass involved. There is the universal principle - the further inductive leap of imagination - needed to get a proper theory going.

    And so a sharp picture of this thing called gravity swims into theoretical view. Eventually we can crank out predictions and begin to support the theory's newly acquired, strictly deductive, form with a sufficient weight of inductive confirmation.

    Induction and deduction are initially entwined so closely as an if-then inference to the best explanation that the lines are blurred. The mind abductively has to juggle both at once in loose fashion.

    But the goal - as a scientist - is to arrive at a clean separation between a theory and its truth. In the end, you want the deductive bit to stand alone as some mathematical grammar that encodes a symmetry and its symmetry breaking. And then the inductive bit becomes the evidence that supports that theoretical structure in terms of the observables that are close enough to whatever was predicted not to count as an unwanted surprise.
  • Banno
    Indeed, he did use that term in his rules for scientific reasoning.
  • Moliere
    A bit late but I do want to say I didn't want to "out" you in speaking to Banno. I have liked his exchanges with you because it's helped me get a better grasp of your philosophical orientation -- and, even if it may be frustrating for you -- I enjoy that fact.

    I do not think of you as "outsider"; just thought that was worth mentioning with some of your posts I read here.
  • apokrisis
    Hey, that's fine. I don't take things personally. It's all about the cut and thrust of ideas. But thanks for saying that.
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