In It’s Not Easy Being Grue, I argued for skepticism — or at least incredulity — towards any inductive inference made solely by appealing to a posteriori evidence. Two hypotheses, as long as they have a logical content greater than the evidence and are not yet refuted are, as a matter of following the rules of logic, necessarily equally favored by the evidence. Even if one should appeal to one of the two hypotheses having a natural property, this problem still stands, since it cannot be uncovered through a posteriori investigation. Of course, more than two hypotheses fit this criteria — any number of empirically adequate hypotheses with greater logical content than the evidence may be constructed. In sum, favoring one hypothesis over another, even with an a prior warrant, cannot be determined from a posteriori evidence at all.
Archive for the ‘underdetermination’ Category
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?
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?
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.
If argument is to provide sufficient reasons for accepting or rejecting a claim, then why is disagreement possible?
Agreement is valued everywhere: it sounds friendlier and builds communities of like-minded individuals. Valuing unanimity, we may accept tradition without asking too many questions. Agreement is easy, and invites acceptance of ideas without much thought, whereas disagreement is criticism, involving a great deal of creativity and willingness to go against the grain, and more often than not produces conflict. Kuhn advocated agreement in his ‘normal science’, knowing that science and a measure of dogmatism occur naturally: there are far worse traditions than science. There is an alternative to this admittedly irrationalist solution, namely a rational justification: as Bacon said, by far the best proof is experience. The problem then becomes how does experience justify theory?