LOGICAL POSITIVISM

LOGICAL POSITIVISM . Narrowly defined, logical positivism was an organized, science-oriented movement centered in Vienna during the 1920s and 1930s, a movement severely critical of metaphysics, theology, and traditional philosophy. Also known as logical empiricism, logical positivism may be more broadly defined as a doctrine born of classical empiricism and nineteenth-century positivism and sharpened by an empirical interpretation of the early logical writings of Ludwig Wittgenstein (1889–1951).

In either case, the distant origins of logical positivism lie in the long history of philosophical empiricism, the tradition holding that all knowledge must be derived from human experience alone. More particularly, the empiricism of John Locke (1632–1704), George Berkeley (1685–1753), and David Hume (1711–1776), with their cumulatively ever more radical elimination of nonempirical sources of knowledge, served as inspiration for the scientific views of the influential Vienna physicist and theorist of science, Ernst Mach (1836–1916). In addition, the positivist movement of the nineteenth century, founded by Auguste Comte (1798–1857), with its intense admiration for natural science, its anticlerical and antimetaphysical commitments, and its self-conscious programs for social and religious reform, lay behind not only Mach but also the small group of mathematical, natural, and social scientists who gathered in Vienna as early as 1907 to discuss Mach's views. In 1922 this group was successful in bringing Moritz Schlick (1882–1936), who was scientifically trained under the great German physicist Max Planck (1858–1947) but also keenly interested in philosophical issues, to the chair once held by Mach at the University of Vienna. Schlick quickly drew around him a circle of like-minded thinkers, mainly from the sciences, some of whom formed in 1928 the Verein Ernst Mach (the Ernst Mach Society). What soon became known as logical positivism was formulated by this group. The Vienna Circle, as they came to be known, issued a "manifesto" in 1929, organized international meetings, and in 1930 took over a journal, renamed Erkenntnis, for the advancement of its increasingly sharp position.

The distinctively "logical" character of the radically empiricist Vienna Circle was derived from the careful study (a line-by-line examination from 1924 to 1926) of Wittgenstein's Tractatus Logico-Philosophicus, which had been completed by 1918 and first published in 1921 (in German under the title Logisch-philosophische Abhandlung ), just prior to the formation of the Vienna Circle. Wittgenstein was never a member of the Circle and was not sympathetic either to its party spirit or to the "grandiloquence" of its pronouncements, but from 1927 to 1929 he engaged in conversations with Schlick and other members of the Circle. Wittgenstein's logical doctrine formed the Circle's sharpest weapon against metaphysics and theology: the characterization of them not merely as false or outmoded, as Comte and the classical positivists had claimed, but as strictly "nonsense."

It was from Wittgenstein that the Vienna Circle drew its insistence that all meaningful statements are either analytic (and logically certain merely because they are tautologies) or synthetic (and "truth-functionally" analyzable into basic propositions corresponding to ultimately simple facts). The Circle gave its own characteristic interpretation of what qualified as these "atomic facts": sense-experiences. With this interpretation came support for two of the Circle's three primary positions: (1) the doctrine of the unity of science, Mach's key project, on the ground that all the sciences can be reduced equally to variously complex ("molecular") reports on experience; and (2) the doctrine of the valuelessness of metaphysics, on the ground that metaphysical utterances, by attempting to go "beyond" experience, fail to point to simple sense-experiences and thus are devoid of cognitive content.

Both doctrines were incorporated in and defensible by the third, the single most characteristic doctrine enunciated by the logical positivists: the verification principle of meaning, fashioned in light of Wittgenstein's analysis of the logic of language. The principle itself, "the meaning of a proposition is the method of its verification," though not appearing in the Tractatus Logico-Philosophicus, was attributed to a remark by Wittgenstein and was first published in the initial volume of Erkenntnis (1930–1931). In all its many later versions, the verification principle was taken to mean that for any nonanalytic (i.e., any would-be informative) statement, the factual meaning of the statement is equivalent to the set of observations (or sense-experiences, or "observation-statements") that would be sufficient to confirm the assertion's truth. Thus a thoroughgoing empiricist interpretation was given to Wittgenstein's more general dictum, and the authority of a powerful theory of meaning was placed behind the old disavowal of metaphysical or theological claims.

Those purported claims, it was said, must (if nontautological) be equivalent to the sensory experiences that might be obtained by an observer ideally positioned to verify the claim. Such confirming experiences, in the end, are alone what the utterances can mean. But if there are (and could be) no such specifiable experiences, as in the case of utterances allegedly "about" nonsensory entities like "God" or the "Absolute," then literally nothing is conveyed by the language, no real claims are made, and no "entity" can be conceived, much less believed in. So ran the fresh, essentially polemical argument of the logical positivists.

This polemic was generally ignored in the German-speaking philosophical world, doubtless because the Vienna Circle was not perceived (and to a large extent did not perceive itself) as engaging in philosophy so much as in a critique, enunciated mainly by professional scientists on behalf of a scientific method and worldview, of philosophy itself. Some English-speaking philosophers, however, long nurtured in the empiricist tradition that had inspired Mach and the Vienna Circle, were quick to notice the logical positivists. Alfred Jules Ayer (1910–1989) and Gilbert Ryle (1900–1976), of Oxford, and John Wisdom (1904–1993) and Susan Stebbing (1885–1943), of Cambridge, were early interpreters of the movement. Ayer, visiting Vienna in 1933, attended the meetings of the Circle, and in 1936 his book Language, Truth and Logic, containing a logical positivist critique of theology and ethics, exploded onto the English-speaking scene.

This radical challenge to the logical intelligibility of central theological utterances—those ostensibly about God, the soul, life after death, and the like—provoked a reaction that, though muted by the outbreak of World War II, intensified again in the early 1950s after a renewed challenge was issued by Antony Flew (b. 1923). Flew drew upon a variation of the verification principle for his question: what empirical observations would be incompatible with (would "falsify") theological assertions? If the answer is none, then are not the assertions in fact empty of definite, thinkable content? Theologians in the Catholic tradition (Roman or Anglican) tended to answer in terms of traditional doctrines of analogy. Members of the reformed tradition replied in fideistic terms. Neither group offered direct responses to the logical positivist attack. On the other hand, a third group, mainly liberal Protestants (including some Anglicans), attempted to vindicate the cognitive meaningfulness of theological discourse by satisfying the conditions set by the verification principle, specifying experiences that would be relevant to the verification or falsification of the claims in question. John Hick (b. 1922) proposed that claims about God could be verified, but only by postmortem experiences. Basil Mitchell (b. 1917) suggested that ordinary historical events or personal experiences are relevant to the verification of these claims, though not conclusively (as in many complex or ambiguous situations in life). He further suggested that faith-commitments are shown to be cognitively significant precisely because of the anguish sometimes felt in maintaining them against the evidence. R. M. Hare (1919–2002) and John Wisdom agreed that ordinary cognitive content is missing from theological claims but that these utterances might still have importance otherwise, offering comprehensive interpretations of particular experiences.

This variety of replies, to which many others could be added, underscores the distance that the postwar discussion had come from the rigorous either/or position of the Vienna Circle. But the sharp sword of the verification principle had already been blunted on issues at the very center of logical positivist concern: issues involving the adequate analysis of scientific assertions themselves. Try as they might, the members and allies of the Vienna Circle were not able to make good their program to include with the same criteria all scientifically essential statements but to exclude all metaphysical and theological ones. It soon became clear that the laws of science, being entirely universal in form, are not conclusively verifiable, since finite numbers of observations cannot in principle verify a universal assertion. ("Some" examples, however many they may be, cannot verify claims about "all.") Furthermore, the proffered suggestion that scientific laws are not, after all, assertions, as they seem to be, but disguised "rules" or other logical entities was too paradoxical for most science supporters. Again, the apparently definite meaning of even straightforward, particular factual assertions of science and daily life was found to melt away under verificational analysis into an infinite series of possible observations. Reversing the problem to the criterion of "falsification" did not help, since although a universal proposition can be falsified (in principle) by a single negative observation, no particular assertion can be so falsified; furthermore, universal laws of science are not, either in logic or in historical fact, at once falsified by negative observations. At most a whole network of theories is shown to need revision by a negative observational result (since it is not immediately clear which of the premises ought to be discarded and which retained). Moreover, as argued by such historians of science as Thomas S. Kuhn (1922–1996), science does not actually develop in any such logically neat way.

Other applications, not directly fashioned by the Vienna Circle, of verificationism to science—for instance, the attempt of the Harvard physicist P. W. Bridgman (1882–1961) to reduce all concepts in science to descriptions of specific procedures ("operationalism")—resulted in the unsatisfactory conclusion that entirely different concepts (for example, of "length" or "time") would be fashioned by the various sciences, depending on their subject matter and characteristic methods. Far from supporting the unity of science, which was a central motive in the founding of the logical positivist movement, operationalism tended to make it logically impossible for astronomy, which measures distance by various sorts of procedures, to share a common concept of distance with geology, biology, or microphysics, which rely upon others. Indeed, even within the same science—or within the same laboratory on different occasions—scientifically essential conceptual generality was seen to be forfeited by the particularistic reductionism of operationalism.

Equally alarming to many more realistically minded scientists and friends of science was the problem of retaining a (non-"metaphysical") concept of the common world studied by science if the meanings of all factual propositions are to be literally equated with those experiences that could verify them. Since experiences are personal and private, the traditional problem of "other minds" (i.e., of how I can escape solipsism if other centers of consciousness are not directly observable by me) was added to the problem of escaping from absolute idealism (i.e., the alarmingly traditional metaphysical view that nothing exists except mentality), even if the egocentric predicament somehow could be avoided.

Finally, the logical status of the verification principle itself could not withstand verificationist analysis. The principle is not just another empirical hypothesis: that is, it certainly does not offer a foothold for confirmation (or falsification) by sense-experiences. Is it then an empty tautology? Most logical positivists took the latter position, holding that the principle was an "important" tautology that had many good reasons for being "recommended" to the intellectual community. This tack, however, allowed others, like Hare and Wisdom, to speak of equally "important" nonverifiable utterances and to make more complex counterrecommendations about the meaning of "meaning."

The disintegration of the organized Vienna Circle can be dated from the murder by a deranged student of Schlick in 1936. Viewed with hostility by the Nazis, the Vienna Circle was formally disbanded in 1938, and in the same year Erkenntnis was moved out of Hitler's direct sphere of control, to Holland, where it lasted only another two years. The end of the broader movement is harder to trace, and in some fashion it remains influential as an overtone in the more radically empirical voices of our time. Still, the gradual abandonment by Wittgenstein of his own either/or position on meaning in the Tractatus Logico-Philosophicus, in favor of a much more pluralistic approach to the functions of human language, pulled the logical rug out from under logical positivism. Its significance for religion and theology continues to lie in the fact that theologians now have been forced to acknowledge the extent to which their claims cannot be treated as simple empirical hypotheses, open to "crucial experiments," as in the contest between Elijah and the priests of Baal (1 Kgs. 18:17–40). Indeed, it may be thought that theology has emerged the better for its cold bath in verificationism, if only because theologians are now required to be aware of the subtlety of their speech and of the many functions it may have both in their technical discourses and in the living religious speech of the faithful.

See Also

Analytic Philosophy; Comte, Auguste; Empiricism; Hume, David; Locke, John; Positivism; Science and Religion; Wittgenstein, Ludwig.

Bibliography

No single book is more important for the understanding of logical positivism than Ludwig Wittgenstein's difficult but fascinating Tractatus Logico-Philosophicus (London, 1922). As a general guide to Wittgenstein's thought and to the Tractatus in particular, one might turn to part 1 of George Pitcher's helpful The Philosophy of Wittgenstein (Englewood Cliffs, N.J., 1964). The thought of the founder of the Vienna Circle is reflected in Moritz Schlick's posthumously published Gesammelte Aufsätze 1926–36 (1938; reprint, Hildesheim, 1962). Other representative writings of the Vienna Circle can be found in Rudolf Carnap's The Logical Structure of the World (London, 1967) and in Foundations of the Unity of Science, vol. 2 of International Encyclopedia of Unified Science, edited by Otto Neurath, Rudolf Carnap, and Charles Morris (1938–1962; reprint, Chicago, 1955–1970). The explosive introduction of logical positivism to the English-speaking world was through Alfred Jules Ayer's Language, Truth and Logic (London, 1936). After World War II, the key book in focusing the theological aspect of the controversy was New Essays in Philosophical Theology, edited by Antony Flew and Alasdair MacIntyre (London, 1955). One of the important sustained efforts to meet the challenge by offering theological verification of a sort, though not in this life, was John Hick's Faith and Knowledge, 2d ed. (Ithaca, N.Y., 1966). A detailed analysis of the arguments leading to the verificationist challenge to religious belief, of various attempted replies, and of the transformation of the issues resulting from this debate can be found in the first chapters of my Language, Logic, and God (New York, 1961). The best recent survey of the whole phenomenon of logical positivism, readable and authoritative, is Oswald Hanfling's Logical Positivism (New York, 1981).

New Sources

Coffa, Alberto. The Semantic Tradition from Kant to Carnap: To the Vienna Station. 1991; reprint New York, 2003.

Fitch, G. W. "On Theoretical Identifications." Philosophical Perspectives 11 (October 2001): 379–393.

Friedman, Michael. Reconsidering Logical Positivism. New York, 1999.

Jones, Todd. "The Virtues of Nonreduction, Even When Reduction Is a Virtue." Philosophical Forum 34 (Summer 2003): 121–141.

Sarkar, Sahotra. Decline and Obsolescence of Logical Empiricism: Carnap vs. Quine and the Critics. Science and Philosophy in the Twentieth Century: Basic Works of Logical Empiricism. New York, 1996.

Schaffer, Jonathan. "Is There a Fundamental Level?" Nous 37 (September 2003): 498–518.

Frederick FerrÉ (1987)

Revised Bibliography