Tag Archive: theory

Infinite learning

Thus every statement (or ‘basic statement’) remains essentially conjectural; but it is a conjecture which can be easily tested. These tests, in their turn, involve new conjectural and testable statements, and so on, ad infinitum; and should we try to establish anything with our tests, we should be involved in an infinite regress. But as I explained in my Logic of Scientific Discovery (especially section 29), we do not establish anything by this procedure: we do not wish to ‘justify’ the ‘acceptance’ of anything, we only test our theories critically, in order to see whether or not we can bring a case against them. [521]

Severely risky

A serious empirical test always consists in the attempt to find a refutation, a counterexample. In the search for a counterexample, we have to use our background knowledge; for we always try to refute first the most risky predictions, the ‘most unlikely … consequences’ (as Peirce already saw); which means that we always look in the most probable kinds of places for the most probable kinds of counterexamples—most probable in the sense that we should expect to find them in the light of our background knowledge. Now if a theory stands up to many such tests, then, owing to the incorporation of the results of our tests into our background knowledge, there may be, after a time, no places left where (in the light of our new background knowledge) counter examples can with a high probability be expected to occur. But this means that the degree of severity of our test declines. This is also the reason why an often repeated test will no longer be considered as significant or as severe: there is something like a law of diminishing returns from repeated tests (as opposed to tests which, in the light of our background knowledge, are of a new kind, and which therefore may still be felt to be significant). These are facts which are inherent in the knowledge-situation; and they have often been described—especially by John Maynard Keynes and by Ernest Nagel—as difficult to explain by an inductivist theory of science. But for us it is all very easy. And we can even explain, by a similar analysis of the knowledge-situation, why the empirical character of a very successful theory always grows stale, after a time. We may then feel (as Poincaré did with respect to Newton’s theory) that the theory is nothing but a set of implicit definitions or conventions—until we progress again and, by refuting it, incidentally re-establish its lost empirical character. (De mortuis nil nisi bene: once a theory is refuted, its empirical character is secure and shines without blemish.) [325-6]

Fisher’s severe tests

In choosing the grounds upon which a general hypothesis should be rejected, the exprimenter will rightly consider all points on which, in the light of current knowledge, the hypothesis may be imperfectly accurate, and will select tests, so far as possible, sensitive to these possible faults, rather than to others. [47]

The freedom to come up with different answers

Poppers Botschaft ist klar. „Wir können nicht wissen“, sagt er, „wir können nur mutmaßen.“ Da keine wissenschaftliche Theorie endgültig beweibar ist, kommt es darauf an, immer erneut und mit ganzer Kraft zu prüfen, ob akzeptierte Theo­rien falsch sind, irrig oder widerlegt. Um dies zu tun, müssen wir die Bedingungen rationaler, kritischer Auseinander­setzung aufrechterhalten, unter denen es möglich bleibt, verschiedener Auffassung zu sein. Was für unser Wissen gilt, gilt auch für unser Verhalten und unsere Politik. Da niemand alle Antworten kennt, müssen wir vor allem sicherstellen, daß es möglich bleibt, unterschiedliche Antworten zu geben. [13]

Provoking the ‘belief philosophers’

In upholding an objective third world [World 3] I hope to provoke those whom I call ‘belief philosophers’: those who, like Descartes, Locke, Berkeley, Hume, Kant, or Russell, are interested in our subjective beliefs, and their basis or origin. Against these belief philosophers I urge that our problem is to find better and bolder theories; and that critical pre­ference counts, but not belief. [107]

Nothing can be proved

The critical attitude, the tradition of free discussion of theories with the aim of discovering their weak spots so that they may be improved upon, is the attitude of reasonableness, of rationality. It makes far-reaching use of both verbal argu­ment and observation—of observation in the interest of argument, however. The Greeks’ discovery of the critical method gave rise at first to the mistaken hope that it would lead to the solution of all the great old problems; that it would establish certainty; that it would help to prove our theories, to justify them. But this hope was a residue of the dogmatic way of thinking; in fact nothing can be justified or proved (outside of mathematics and logic). The demand for rational proofs in science indicates a failure to keep distinct the broad realm of rationality and the narrow realm of rational certainty: it is an untenable, an unreasonable demand. [67]

Misguided “scientism”

Um den Gehalt dieser meiner Hauptthese und ihre Bedeutung für die Soziologie ein wenig anzudeuten, wird es zweck­mäßig sein, ihr gewisse andere Thesen einer weit verbreiteten und oft ganz unbewußt absorbierten Methodologie gegenüberzustellen.

Da ist zum Beispiel der verfehlte und mißverständliche methodologische Naturalismus oder Szientismus, der verlangt, daß die Sozialwissenschaften endlich von den Naturwissenschaften lernen, was wissenschaftliche Methode ist. Dieser verfehlte Naturalismus stellt Forderungen auf wie: Beginne mit Beobachtungen und Messungen; das heißt zum Bei­spiel, mit statistischen Erhebungen; schreite dann induktiv zu Verallgemeinerungen vor und zur Theorienbildung. Auf diese Weise wirst Du dem Ideal der wissenschaftlichen Objektivität näher kommen, soweit das in den Sozialwissen­schaften überhaupt möglich, ist. Dabei mußt Du Dir darüber klar sein, daß in den Sozialwissenschaften die Objektivität weit schwieriger zu erreichen ist (falls sie überhaupt zu erreichen ist) als in den Naturwissenschaften; denn Objektivität bedeutet Wertfreiheit, und der Sozialwissenschaftler kann sich nur in den seltensten Fällen von den Wertungen seiner eigenen Gesellschaftsschicht soweit emanzipieren, um auch nur einigermaßen zur Wertfreiheit und Objektivität vor­zudringen.

Meiner Meinung nach ist jeder der Sätze, die ich hier diesem verfehlten Naturalismus zugeschrieben habe, grund­falsch und auf ein Mißverständnis der naturwissenschaftlichen Methode begründet, ja geradezu auf einen Mythus – einen leider allzu weit verbreiteten und einflußreichen Mythus vom induktiven Charakter der naturwissenschaftlichen Methode und vom Charakter der naturwissenschaftlichen Objektivität. [83]

The problem is epistemology, not statistics

Significance tests have a role to play in social science research but their current widespread use in appraising theories is often harmful. The reason for this lies not in the mathematics but in social scientists’ poor understanding of the logical relation between theory and fact, that is, a methodological or epistemological unclarity. Theories entail observations, not conversely. Although a theory’s success in deriving a fact tends to corroborate it, this corroboration is weak unless the fact has a very low prior probability and there are few possible alternative theories. The fact of a nonzero difference or correlation, such as we infer by refuting the null hypothesis, does not have such a low probability because in social science everything correlates with almost everything else, theory aside. In the “strong” use of significance tests, the theory predicts a numerical point value, or narrow range, so the hypothesis test subjects the theory to a grave risk of being falsified if it is objectively incorrect. In general, setting up a confidence interval is preferable, being more informa­tive and entailing null hypothesis refutation if a difference falls outside the interval. Significance tests are usually more defensible in technological contexts (e.g., evaluating an intervention) than for theory appraisal. [393]

Scientism: slavishly aping a myth

But I should go even further and accuse at least some professional historians of ‘scientism’: of trying to copy the method of natural science, not as it actually is, but as it is wrongly alleged to be. This alleged but non-existent method is that of collecting observations and then ‘drawing conclusions’ from them. It is slavishly aped by some historians who believe that they can collect documentary evidence which, corresponding to the observations of natural science, forms the ’empirical basis’ for their conclusions. …

Worse even than the attempt to apply an inapplicable method is the worship of the idol of certain or infallible or authoritative knowledge which these historians mistake for the ideal of science. Admittedly, we all try hard to avoid error; and we ought to be sad if we have made a mistake. Yet to avoid error is a poor ideal: if we do not dare to tackle problems which are so difficult that error is almost unavoidable, then there will be no growth of knowledge. In fact, it is from our boldest theories, including those which are erroneous, that we learn most. Nobody is exempt from making mistakes; the great thing is to learn from them. [186]

More falsificationism strawmen going up in flames

A second familiar approach from the same period is Karl Popper’s ‘falsificationist’ criterion, which fares no better. Apart from the fact that it leaves ambiguous the scientific status of virtually every singular existential statement, however well supported (e.g., the claim that there are atoms, that there is a planet closer to the sun than the Earth, that there is a missing link), it has the untoward consequence of countenancing as ‘scientific’ every crank claim which makes ascertainably false assertions. Thus flat Earthers, biblical creationists, proponents of laetrile or orgone boxes, Uri Geller devotees, Bermuda Triangulators, circle squarers, Lysenkoists, charioteers of the gods, perpetuum mobile builders, Big Foot searchers, Loch Nessians, faith healers, polywater dabblers, Rosicrucians, the-world-is-about-to-enders, primal screamers, water diviners, magicians, and astrologers all turn out to be scientific on Popper’s criterion – just so long as they are prepared to indicate some observation, however improbable, which (if it came to pass) would cause them to change their minds. [121]

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