Logical positivism

Logical empiricism (sometimes called logical empiricism, neo-positivism, or rational empiricism) is a philosophical school primarily exemplified by the Vienna Circle, founded by a group of Viennese scientists and philosophers in the 1920s. The Vienna Circle was above all a place of discussion between scientists (Niels Bohr and Einstein occasionally intervened) and philosophers who did not share the same convictions.

It was formed around the philosopher Moritz Schlick, and it includes the mathematicians Hans Hahn and Karl Menger, the physicist Philipp Frank, the sociologist Otto Neurath, the philosophers Rudolf Carnap and Victor Kraft, as well as philosophy students like Friedrich Waismann and Herbert Feigl. At the same time, in Berlin, sympathizers gathered around Hans Reichenbach and the Gesellschaft für Empirische Philosophie (Society for Empirical Philosophy). Founded in 1928, it included as members Carl Gustav Hempel, Richard von Mises, David Hilbert and Kurt Grelling.

The Vienna Circle is the author of a manifesto, published in 1929 under the title The scientific conception of the world, in which it sets out its main theses. We can also quote Alfred J. Ayer, who summarized the great theses of logical positivism, in his work Langage, Truth and Logic (1936). We can briefly summarize these as follows: there does not exist, as Kant claimed, a synthetic a priori judgment. Therefore, metaphysics cannot be a science. On the other hand, any statement of knowledge is either analytical or synthetic a posteriori, and therefore verifiable by experience. Consequently, ethical and metaphysical statements are, as prescriptive and non-descriptive and verifiable statements, necessarily “meaningless”. Logical positivism is thus at the origin of the sharp dichotomy between “facts” and “values” (taken up by legal positivism), which was subsequently partially questioned.

The positivist legacy

Logical positivism, or neo-positivism, arose from the positivism of Ernst Mach, Henri Poincaré and the thought of young Wittgenstein. Positivism is above all focused on the study of science. He seeks to break with the methods of theology and “metaphysics”, which would seek, according to them, gods or mysterious causes to explain the phenomena. Positivism renounces giving causes to phenomena and seeks only to provide laws making it possible to describe and predict them. On this point, logical positivism is perfectly faithful to the first positivism, formulated in the nineteenth century by Auguste Comte (one could even add that it does not differ, on this point, from the Kantian criticism distinguishing between the knowledge of phenomena and that, impossible, noumena: logical positivism thus shared, to a certain extent, the point of view of Kantianism on the distinction between science and belief). It is a question of describing and justifying scientific discoveries by analyzing their approach and their principles, of asking the question how can the world be like this? (and not why is it so?).

However, it differs from Auguste Comte’s positivism by its empiricism. In Comte, in fact, sensitive experience is very largely determined by the theories at our disposal to understand it and has no priority, whereas logical positivism considers, in the continuation of the empiricism of Locke and Hume, that sensation is the foundation of knowledge. The sensations are absolutely unmistakable, and can therefore, when formulated in precise language, be used to create scientific theories. The sensations must take the form of protocol statements describing that a certain sensation has been felt at such and such a place and time by such and such a person. The protocol propositions being absolutely true, science only has to understand the relations between these propositions to obtain a complete theory of physical reality. In this, Ernst Mach is the true precursor of the Vienna Circle, because he already defended the idea that the concept of objective reality was not useful in science. According to him, science would only organize in a rational and precise way the relations between our sensations.

If the sciences can all be based on protocol proposals, then the sciences will have a unity not only methodological but also theoretical. There is no longer any reason in principle to distinguish the different sciences according to their field, as Comte did. Ultimately, according to Quine, the unity of science is based on the unity of reality. All phenomena (biological, social, cultural, etc.) are reducible to physical phenomena, that is to say they are fully descriptible from the fundamental laws of physics. This reductionism of the sciences to physics alone takes the name of “physicalism”.

On the other hand, logical positivism, like positivism, is not without political concerns. Close to socialism and social democracy, the Vienna Circle and the Berlin Society for Scientific Philosophy identified on the one hand the struggle against German idealism with the global project of eliminating metaphysics, and on the other hand saw their criticism as a form of resistance to the irrationalism of fascist ideology. According to the 1929 manifesto, science is a conception of the world in its own right, and not simply a discipline which one can or cannot engage in. Politics too must renounce its “metaphysical dogmas” and be governed by scientific principles: the Comtian project, precursor of technocracy, is resumed. Neurath, in particular, gave its political dimension to the Vienna Circle.

Includes texts translated from Wikipedia