Қуайннің «Эмпиризмнің екі догмасы»: Аналитикалық-синтетикалық айырмашылық пен редукционизмге сын

1951 philosophy article by Willard Van Orman Quine
"Two Dogmas of Empiricism" is a paper by analytic philosopher Willard Van Orman Quine published in 1951. According to University of Sydney professor of philosophy Peter Godfrey Smith, this "paper [is] sometimes regarded as the most important in all of twentieth century philosophy". The paper is an attack on two central aspects of the logical positivists' philosophy: the first being the analytic–synthetic distinction between analytic truths and synthetic truths, explained by Quine as truths grounded only in meanings and independent of facts, and truths grounded in facts; the other being reductionism, the theory that each meaningful statement gets its meaning from some logical construction of terms that refer exclusively to immediate experience. "Two Dogmas" has six sections. The first four focus on analyticity, the last two on reductionism. There, Quine turns the focus to the logical positivists' theory of meaning. He also presents his own holistic theory of meaning.

Analyticity would be acceptable if we allowed for the verification theory of meaning: an analytic statement would be one synonymous with a logical truth, which would be an extreme case of meaning where empirical verification is not needed, because it is "confirmed no matter what". "So, if the verification theory can be accepted as an adequate account of statement synonymy, the notion of analyticity is saved after all." The problem that naturally follows is how statements are to be verified. An empiricist would say that it can only be done using empirical evidence. So some form of reductionism "the belief that each meaningful statement is equivalent to some logical construct upon terms which refer to immediate experience" must be assumed in order for an empiricist to 'save' the notion of analyticity. Such reductionism, says Quine, presents just as intractable a problem as did analyticity. In order to prove that all meaningful statements can be translated into a sense datum language, a reductionist would surely have to confront "the task of specifying a sense datum language and showing how to translate the rest of significant discourse, statement by statement, into it." To illustrate the difficulty of doing so, Quine describes Rudolf Carnap's attempt in his book Der logische Aufbau der Welt. Quine first observes that Carnap's starting point was not the strictest possible, as his "sense datum language" included not only sense events but also "the notations of logic, up through higher set theory Empiricists there are who would boggle at such prodigality." Nonetheless, says Quine, Carnap showed great ingenuity in defining sensory concepts "which, but for his constructions, one would not have dreamed were definable on so slender a basis." However, even such admirable efforts left Carnap, by his own admission, far short of completing the whole project. Finally, Quine objects in principle to Carnap's proposed translation of statements like "quality q is at point instant x;y;z;t" into his sense datum language, because he does not define the connective "is at". Without statements of this kind, it is difficult to see, even in principle, how Carnap's project could have been completed. The difficulty that Carnap encountered shows that reductionism is, at best, unproven and very difficult to prove. Until a reductionist can produce an acceptable proof, Quine maintains that reductionism is another "metaphysical article of faith".

Instead of reductionism, Quine proposes that it is the whole field of science and not single statements that are verified. All scientific statements are interconnected. Logical laws give the relation between different statements, while they also are statements of the system. This makes talk about the empirical content of a single statement misleading. It also becomes impossible to draw a line between synthetic statements, which depend on experience, and analytic statements, that hold come what may. Any statement can be held as necessarily true according to Quine, if the right changes are made somewhere else in the system. In the same way, no statements are immune to revision. Even logical laws can be revised according to Quine. Quantum logic, introduced by Garrett Birkhoff and John von Neumann, abandons the law of distributivity from classical logic in order to reconcile some of the apparent inconsistencies of classical Boolean logic with the facts related to measurement and observation in quantum mechanics. He states also that a revision of the law of excluded middle has been proposed as a means of simplifying quantum mechanics. Quine makes the case that the empirical study of physics has furnished apparently credible grounds for replacing classical logic by quantum logic, rather as Newtonian physics gave way to Einsteinian physics. The idea that logical laws are not immune to revision in the light of empirical evidence has provoked an intense debate (see "Is Logic Empirical?"). According to Quine, there are two different results of his reasoning. The first is a blurring of the line between metaphysics and natural science. The common sense theory about physical objects is epistemologically comparable to the gods of Homer. Quine is a physicalist, in the sense that he considers it a scientific error not to adopt a theory which makes reference to physical objects. However, like Gods of Homer, physical objects are posits, and there is no great epistemic difference in kind; the difference is rather that the theory of physical objects has turned out to be a more efficient theory. After having defined himself an "empiricist", Quine states in Two Dogmas: "The myth of physical objects is epistemologically superior to most in that it has proved more efficacious than other myths as a device for working a manageable structure into the flux of
experience". The second result is a move towards pragmatism. Since, Quine says, the function of science is to predict future experiences in the light of past ones, the only ground for choosing which explanations to believe is "the degree to which they expedite our dealings with sense experiences." While pragmatic concerns are important for Carnap and other logical positivists when choosing a linguistic framework, their pragmatism "leaves off at the imagined boundary between the analytic and the synthetic". For Quine, every change in the system of science is, when rational, pragmatic.

Reprinted in his 1953 From a Logical Point of View. Harvard University Press.