Thursday, August 8, 2019

The History of Positivism (Pt. III): The Vienna Circle and Logical Positivism


(Note: This will make more sense to those who have read part II)

Between 1900 (which is where the last post left off) and 1929, when the Vienna Circle of Logical Positivists published their Manifesto http://evidencebasedcryonic... , there were several developments that influenced the latter. These include Einstein's physics and early Quantum Mechanics; the invention of powerful new formal systems of logic, especially those of Frege, Russell and Whitehead which were thought to provide the foundation for all mathematics; the work of young Ludwig Wittgenstein in separating meaningful from nonsensical statements in his Tractatus Logico-Philosophicus; and the sense after the catastrophe of WWI that a scientific approach to solving social problems and rebuilding society was crucial to a a peaceful, rational and progressive civilization in contrast to the nationalism and irrationalism that had been loosed on Europe during the Great War. These factors and others were taken up in the Logical Positivist/Vienna Circle Manifesto, called The Scientific Conception of the World. Tellingly, the members had backgrounds in diverse disciplines of natural and social science. To take just the most prominent of the leading figures, Moritz Schlick (the nominal leader) was a trained physicist and former student of Max Planck, who had turned largely to what we now call philosophy of science (for logical positivists philosophy itself was more or less equivalent to an applied philosophy of science as we will see). Otto Neurath was a sociologist and political economist with a particular fondness for statistical and other mathematical models; he was one of the more politicized members. Rudolf Carnap had a background in physics and pure mathematics, including the new logic of Frege, Russell and Whithead. There were 14 members and even more "sympathizers" who signed the document and had attended the formative discussions and meetings that had been hosted by the Ernst Mach Society, which Schlick and Neurath (among others) had established. The Manifesto states that not all members agreed on everything, but that the overlaps were significant enough to justify the declaration of a movement that shared a commitment to "what is the essence of the new scientific world conception in contrast with traditional philosophy." (1929; 13)

According to the manifesto the job of logical positivists is not so much to establish novel philosophical assertions as to clarify assertions that have already been put forward in order to separate those which are meaningful statements of logic or fact, and those which are neither, and thus are considered "cognitively meaningless." Such clarification is part of what is called "Logical Analysis" and it was supposed to do at least 2 things: 1) eliminate psuedoscience, theology and metaphysics from scientific consideration, and 2) reveal the logical structure of good scientific theories, whether in physics, biology, sociology or any other area, thus facilitating the improvement of communication between different scientists and leading to a shared general scientific worldview whose applications would improve the human lot. There was thus a socio-political component though, "not every adherent...will be a [politically engaged] fighter."(1929; 16) Nevertheless, the manifesto asserts that all who help to eliminate the residue of metaphysical thinking (which was thought to retard rational thought and the progress of science) are taking part implicitly in the struggle to rationalize and scientize the modern world. The closing words of the document read thus:
"We witness the spirit of the scientific world conception penetrating in growing measure the forms of personal and public life, in education, upbringing, architecture, and the shaping of economic and social life according to rational principles. The scientific world conception serves life, and life receives it." (1929; 16)

The legacy of Auguste Comte looms large here. We must put metaphysics and theology well behind us, clarify the nature of good (i.e. coherent, consistent and fruitful) scientific theories, and map out their internal relatioins and connections to one another via the "Unity of Sciences" project. Though the methods will include the radical empiricism (i.e. phenomenalism) of Mill and above all Mach as they understood him, there will be an emphasis on the role of formal logic in carrying out these ambitious projects. I will summarize briefly a) logical analysis (which involves the famous verifiability criterion of meaning) and b) the unity of science thesis. Reasons for the demise of LP will be mentioned in passing, and discussed in a future post.

Logical Analysis:


Logical analysis is a methodological approach to the precise clarification of conceptual problems that arise in philosophy. It relies on the use of symbolic logic which distinguishes it from earlier forms of empiricism (hence "logical" positivism or empiricism). Symbolic/formal logic is viewed as a precise "Ideal Language" that can be used to evaluate statements in theories for meaningfulness. If any given statement cannot be shown, in principle, to be true or false then it is cognitively meaningless. There are usages that have meaning but are not statements (imperatives and questions for example). But all knowledge claims, all purported cognitive assertions must at least be meaningful before being admitted into a scientific theory or discussion. The cognitive standards of good science are taken to be the cognitive standards of all knowledge claims.

There are 2 kinds of statements-- analytic and synthetic ones. Analytic statements are those which must be true just by virtue of the meanings the terms have. Thus the classic example, "All bachelors are males" is true simply because the definition of the subject (the term, "bachelors") already contains implicitly the definition of the predicate ("males"). By definition bachelors are males. You don't have to do any empirical work to figure that out. One need only know how to understand the terms in play. But there is also nothing new that is learned in such statements according to logical positivists (LPs). If you know what "bachelor" means, you already know that it always refers to males. But scientific knowledge is empirical and additive. The statements used to convey empirical knowledge must be synthetic statements (these terms come from Hume and Kant; and the LPs are largely restating Hume's position here). A synthetic statement would include "There is a bachelor such that he is over the age of fifty." The subject (bachelor) does not contain or entail the predicate ("older than fifty"). This statement must be either True or False. In fancy terms it is "truth apt" (can be true or not-true). Thus it can, in principle, be verified. As long as we know which bachelor is involved and where he is, we can--in principle-- check his birth certificate in order to evaluate the statement as either True or False.

So how does the Analytic-Synthetic dichotomy provide a basis for sorting meaningful and meaningless statements out? Well, there are 2 and only 2 kinds of meaningful statements: a) statements that are true by definition a priori (Analytic statements) and b) empirical statements that can, in principle, be determined to be T or F by means of observations (e.g. checking the birth certificate in above ex.). If a statement occurs which does not conform to these stipulations it is ruled out as meaningless. For example, suppose we are reading Hegel and come across a statement like "Great works of art manifest the Absolute Spirit." Is that true by virtue of the meanings of the terms? Clearly not. The subject-term (Artwork) does not include or entail the meaning of the predicate ("Absolute Spirit"). So it is not an analytical truth. Is it an empirical truth? That is, is it a Synthetic statement which, in principle, could be found to be T or F by means of observation?. That seems unlikely. For just how would one set about verifying that "Great Art manifests Absolute Spirit?" As Moritz Schlick put it, "the meaning of a term is the method of its verification." But what method suggests itself in order to verify or falsify the above claim? None, it would seem. It is consigned to the bin of nonsense statements. Not only are the terms poorly defined in terms of reference, but logical relations between them are utterly lacking. This is the kind of statement LPs deride as metaphysical nonsense obstructing the progress of the scientific worldview which alone leads to knowledge and rational social progress. Yet many philosophers and intellectuals to this day comb through the tomes of Hegel or Schelling, for example, hoping to solve what they take to be serious philosophical problems. The LPs dismiss such matters as "psuedo-problems of philosophy." Similar results follow from their analysis of statements about the divine in religion. Poorly formed scientific hypotheses and "psuedo-science" can also be caught in the net of logical analysis and tossed in the nonsense bin before being taken up by scientists. The LPs thus see themselves as gate-keepers turning away all pretenders to meaningful discourse that do not pass their tests of logical analysis.
In addition to the dichotomy of Analytic and Synthetic statements, there is also a dichotomy between neutral observation terms and theoretical terms. All scientific theory must be reducible to observation statements ("protocol statements") which are uncontaminated by theoretical or speculative baggage--i.e. they must be neutral. In analyzing theories we should come to such statements as "the meter reads notch 6" which is a statement about observations. But that still has theoretical terms like "meter" and "6" which must be reducible to phenomena (as with the extreme empirical views of Mill and Mach on some readings). We must be able to reduce empirical observations to neutral protocol statements like "a rectangular gray patch with a red curved shape at the center" where that may describe a meter with a red dial. This is called "phenomenalism" and though most early LPs favored it, that changed quickly enough as it became clear that such statements themselves stood in need of their own verifiability. Phenomenal experience is as fallible as any other kind, and so new theories of observation which were less stringent appeared. By the mid 30s Carnap and Neurath no longer insisted on phenomenalism (for different and complex reasons). Still, in the 1929 Manifesto the idea was that empirical statements could be reduced to basic phenomenal statements which were unbiased, and so they served as guarantors of empirical legitimacy. In sum, the Theoretical Statements had to be reducible, in principle, to Empirical Statements which had to be capable of being stated in terms of the most basic "Neutral Observation Statements" aka "Protocol Statements. If a theory was to be deemed good, it had to be capable of being stated in terms of symbolic logic which contained analytic and synthetic statements. The synthetic/empirical statements would have to be verifiable to have meaning. They would have to be translatable into the most basic observational statements possible, which statements would have to be entirely free of bias or theoretical baggage. This was the short-lived strong program, circa 1930, which we are examining here. Soon enough revisions, qualifications and intramural disputes in the movement became apparent.

Unity of Science:

As with Auguste Comte, LPs thought of the sciences as unified in terms of a hierarchical and reductionist order. Economics and sociology should, in principle, be reducible to psychology. Psychology should be reducible to biology. Biology should be reducible to chemistry, which should be reducible to physics. Thus, the goal stated in the manifesto was to construct a "Constitutive System" in which all legitimate statements are reduced to lower-level statements which in turn can be reduced to the neutral observation sentences mentioned above.( Note: Reductionism is still alive and well in many quarters of scientific discourse) Aside from reductionism, there was a desire to make the works of scientists working in different disciplines and sub-fields mutually comprehensible. As stated in the manifesto " The endeavor is to link and harmonize the achievements of individual investigators in their various fields of science [in order to facilitate communication and cooperation between these varied scientists]." Ambiguities and misunderstandings were to be eliminated by a logical analysis of the often-sloppy vagaries of natural language. This may have seemed plausible at the time, but the exponential increase in specialization in science has led to a situation in which 2 physicists may not understand each others' research, much less neuroscientists, physicists and sociologists having the ability to keep up with each others' work. Nevertheless, at the time the Vienna group published monographs on the unity of science in Europe until they fled from Nazi persecution in the late 30s.
In the US, many of the emigres continued to pursue the unity of science program by establishing the "International Encyclopedia of Unified Science" which was never completed, though the first section on "Foundations of the Unity of Science" was completed. The entries for that section were published as monograph between 1940 and 1969, and were less unified than was originally hoped. For example, ironically, one entry on the history of science was written by TS Kuhn for a 1962 monograph. It's title is The Structure Of Scientific Revolutions-- a book forever associated with the demise of logical positivism, and associated doctrines. John Dewey, whose pragmatism was only partly compatible with the LPs wrote an early entry on the "Theory of Valuation" in which he employed an instrumental (i.e. non-realist) method in the hope of showing that ethical statements could be treated as scientific working hypothesis subject to some form of verification and falsification. In short, the LPs, now more comfortable with the looser term, Logical Empiricism, had become increasingly diverse and tolerant in approach. Starting in the late 30s Verificationism, a central part of the movement, was already being revised and even abandoned by some members. It was subjected to fierce criticisms in the 50s and 60s (including those of Kuhn published with their own encylopedia's imprimateur). Certainly, by the late 1960s there were few philosophers defending verificationism or clinging to the label "logical positivism." Inasmuch as philosophical movements ever completely "die out," Logical Positivism did just that by the 1970s. Even its former proponents (Ayer, for example) now distanced themselves from the label.

Yet the spirit of the LPs-- their insistence on clarity, rigor, the use of precise formal languages in the service of conceptual analyses-- all these survive to varying degrees in Analytic and so-called "Post Analytic" philosophy today. Also, there has been a revival of interest in the LP movement within the history of philosophy, and it is not inconceivable that those researches may lead to substantive work which draws on some of the scientists and philosophers that constituted the Vienna Circle and LP generally.

----------------------------------------------------------------------------------------------------------------------------------------------

References and Online Resources:

The Scientific Conception of the World: The Vienna Circle (1929) Otto Neurath, Hans Hahn and Rudolf Carnap available online here:  http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.477.4758&rep=rep1&type=pdf

Vienna Circle: Entry in New World Encyclopedia Online: http://www.newworldencyclop...
The Cambridge Companion to Carnap, ed. Michael Friedman & Richard Creath; Cambridge U. Press, 2007

Positivism and Politics; The Vienna Circle as a Social Movement, Marx W. Wartofsky, in The Legacy of The Vienna Circle: Modern Reappraisals, ed. Sahotra Sarkar; Routledge, 1996

The Re-evaluation of Logical Positivism, Michael Friedman; (ibid)

Logical Empiricism: Entry from Stanford Encyclopedia of Philosophy (Online):
https://plato.stanford.edu/...

This 7 minute video is taken from a documentary on 20th century philosophy and provides a short overview of Logical Positivism in the 20s and 30s. Most of the topics I discussed above are summarized in this clip which may help to make early Logical Positivism more accessible.


No comments:

Post a Comment