One solution to Goodman’s new riddle of induction, as proposed by David Lewis and WVO Quine, is that certain languages describe natural properties, which have a special metaphysical status. All things being equal, the evidence will favor the hypothesis that uses languages that have natural properties over any other language in all cases. The problem of choosing between hypotheses that will be favored by the evidence and hypotheses that will not is solved by choosing a hypothesis expressed in a language that uses natural properties. There is, however, a problem with this solution: how can a scientist decide whether a language is using a natural property?
Archive for the ‘quine’ Category
Quine’s problem (which is different from the Duhem problem) begins by calling into question ‘the belief that each meaningful statement is equivalent to some logical construct upon terms which refer to immediate experience.’ (Quine, 39) However it was never Duhem’s intention to save the hypothesis, merely to indicate the element of uncertainty of falsifying evidence. Quine has taken the Duhem problem and extended it so that there is no limit to the set of hypotheses which face a test: “our statements about the external world face the tribunal of sense experience not individually but only as a corporate body.” (ibid, 41)
Of course, Quine is correct in saying that “Any statement can be held true come what may, if we make drastic enough adjustments elsewhere in the system. Even a statement very close to the periphery can be held true in the face of recalcitrant experience by pleading hallucination or by amending certain statements of the kind called logical laws. Conversely, by the same token, no statement is immune to revision,” (ibid, 43) but as Grünbaum shows, this is a trivial result.
It’s best not to reduce Grünbaum’s argument too far, but a brief analysis of the paper is necessary: Grünbaum demonstrates that while the Quine problem is trivially true as a matter of following the rules of logic, it leaves us only with no compelling reason to favor any of our auxiliary hypotheses over our scientific theories, and in its non-trivial form is a non sequitur. Anyone interested in examining Grünbaum’s argument fully can read the paper here [.pdf] (alt link).
In a letter dated June 1, 1962 and printed in Harding (1976), Quine responded to Grünbam. It’s interesting to understand Quine in light of this letter. I’ve reproduced it below, bolding specific passages of note.
Dear Professor Grünbaum:
I have read your paper on the falsifiability of theories with interest. Your claim that the Duhem-Quine thesis, as you call it, is untenable if taken non-trivially, strikes me as persuasive. Certainly it is carefully argued.
For my own part I would say that the thesis as I have used it is probably trivial. I haven’t advanced it as an interesting thesis as such. I bring it in only in the course of arguing against such notions as that the empirical content of sentences can in general be sorted out distributively, sentence by sentence, or that the understanding of a term can be segregated from collateral information regarding the object. For such purposes I am not concerned even to avoid the trivial extreme of sustaining a law by changing a meaning; for the cleavage between meaning and fact is part of what, in such contexts, I am questioning. Actually my holism is not as extreme as those brief vague paragraphs at the end of “Two dogmas of empiricism” are bound to sound. See sections 1-3 and 7-10 of Word and Object.
W. V. Quine
After all, if you see something that appears to be a black swan no matter how many tests are conducted, only by the most tortuous steps can one protect the theory “All swans are white.”
If a basic statement and theory are incoherent, then observation reports cannot inform us that theories are wrong and theories cannot inform us that observation reports are wrong. Either the theories or observation reports are wrong — or both. Neither T1 nor T2 should be adopted a priori, for they effectively annihilate one another: all we can see is an incoherence between T1 and T2.
Furthermore, even after we recognize an incoherence between an observation report and a theory, this ‘recognizing’ is relative to a given system of logic, background assumptions, language, and cognitive framework: we are even fallible in recognizing incoherence. Whatever method or route we follow that leads to preferring one over the other will either not rest on an Archimedean point, or will not be known to rest on an Archimedean point. All is theory-laden and subject to error. We must admit that it is possible to change the logic we employ, statements we adopt, theories we accept, methods we follow, language we use, or the cognitive frameworks we inhabit, for none of them are privileged.
The word ‘induction’ takes on many meanings, always when most convenient. Like a slippery eel, just when a critic of induction has their hands around its neck, it wiggles out once more.
Does induction refer to the ‘context of discovery’ or the ‘context of justification’?
If ‘induction’ refers to the context of discovery, the critic of induction need only point to the greatest historical developments in science. Without blinders on, the critic points out that these theories are birthed in the heat of dealing with significant scientific problems. The framework comes before observation (read: Einstein). How then could enumerative induction work? Theories are then imaginative creations–possible solutions to problems. Even if enumerative induction is permitted during the context of discovery, it does not help the scientist any more than dreaming next to a raging fire (read: Kekulé’s oroboros), drug use (read: Feynman, Kary Mullis), &c., which is to say that is has no privileged position over even the most arbitrary ‘methods.’
If ‘induction’ refers to the context of justification, is this a process of objective inductive verification à la Carnap? If so, then this program is defunct, for no number of verifications can increase the probability assigned to a strictly universal statement. Is this the process of subjective certitude after repeated verifications? Then it contradicts the probability calculus and fails to solve the problem of underdetermination.
If ‘induction’ refers to the metaphysical assumption of regularity of systems, which we may approximate if enough inductions of the system are collected, then the inductivist retreats to asserting only that there exists regularities, calling this assumption ‘induction.’ If a proposed regularity should turn out to be false, then this was either a mistaken induction or not induction at all. If it is not an induction, then this is little more than wordplay: we cannot tell this type of induction apart from a conjecture. If it is a mistaken induction, this type of induction should only be known to be mistaken in hindsight: it tells us nothing until we learn that we are wrong.
And what is that but a falsification?
Positive theories of knowledge assert that, if they are correct, future guesses are guaranteed to have (at least probabilistically) a marked improvement in their objective verisimilitude, not just in their increased empirical adequacy. If this were true, it would be an immense boon for everyone. Logical negativism rules such a possibility out a priori; in fact, it originates in the supposed failure of all positive theories of knowledge. Therefore, the greatest argument one can muster against this dogma in logical negativism is to demonstrate that some kind of necessary increase in verisimilitude occurs when replacing an old theory with a new one.
Teacher: Previously, we touched on how non-scientific statements play a bigger role than Popper first acknowledged. Gamma, you said yesterday that you disagreed with Sigma’s description of the scientific process?
I go to a wedding and I miss a gigantic explosion in the blogosphere over Sir Harold Kroto’s Nobel Laureate lecture. Eh, I’ve missed worse things.
Andrew Brown at The Guardian has an adequate–but far from complete–drubbing of Kroto’s proto-positivist claim that “Science is the only philosophical construct we have to determine TRUTH with any degree of reliability.”
PZ Myers disagrees with Brown, but I’m not surprised. After reading him for a few years, he comes off as a genuine naïve Popperian, saying “If someone were to say something truly false and giggleworthy, like for instance, “all cats are black,” what I’d do is go out and find a Siamese and a white Persian and wave them in his face. Isn’t that obvious?” After Quine, it isn’t so obvious anymore. Isn’t that obvious? PZ is a scientist, and scientists aren’t often paid to think about epistemology, so I won’t hold it against him. Only through a critical discussion can we come to an agreement, tentative though it may be, about things like the color of cats–and yet this agreement is forever provisional. If someone were to point out this distinction in private, PZ would probably temper his initial statement, but headlines sell papers.
Kroto, Myers, and Brown all come off thinking that science is directed at establishing claims–I am apparently the odd man out when I concede that, rather than lifting up other traditions to science’s level, science does not have the epistemic privilege Kroto and PZ think: there is no way to reliably determine the truth.
That said, we can choose to prefer science over other ‘ways of knowing’ for the same reason we can choose to prefer a theory that has survived criticism over one that has not: while its past success at solving our problems provide no ‘good reasons’ for favoring science, the failures of alternative ‘ways of knowing’ are sufficient to provisionally adopt what remains.
One intuitively wouldn’t want to have a set of incoherent beliefs. Preferring incoherence is to be frowned upon, for one belief in this set must be false. Any sort of epistemology should then strive for some kind of coherence and mutual support, and if incoherence is found, of finding a way to determine which member of the set is false and which is true.
There are two kinds of coherentism I’m thinking of: the first kind is sort of a nebulous coherentism, that it is better to prefer a set of beliefs that support one another over a set of incoherent beliefs. I would then call myself a ‘weak’ coherentist in a sense, as would most modern epistemologists, but we strive not just for the coherence of our beliefs as indicating its truth, but for the truth of all of our beliefs.
The second kind of coherentism I will call ‘strict coherentism.’ It sees no recourse necessary to any sort of a posteriori examination. This gambit is played, I think, in order to circumnavigate a serious problem for most justificationists: we may be justified in preferring a coherent system over an incoherent system.
Suppose a man were translated to a planet, the sky of which was constantly covered with a thick curtain of clouds, so that he could never see the other stars. On that planet he would live as if it were isolated in space. But he would notice that it revolves…” (Henri Poincaré, Science and Hypotheses)
Poincaré goes on to note that this man would, if he were observant, notice that a free-swinging pendulum — something akin to Foucault’s pendulum — gradually rotates.
Assume, for the moment, that this man looks around him, at the birds flying through the sky, the trees undulating in the breeze, the houses firmly rooted to the ground, and thinks that the planet does not–cannot–rotate. This is a commonsense conclusion to make. After observing this rotation, the thought-experiment man may conjecture that the planet does or does not rotate.