Logical empiricism , also known as logical positivism or neopositivism , is a position in the philosophy of language , knowledge , science and spirit that is one of the most influential philosophical directions of the 20th century. Its founders include in particular Rudolf Carnap , Hans Reichenbach , Herbert Feigl , Victor Kraft and others; the Vienna Circle and its members played a key role in formulating the program.
Influences, naming and program
The greatest influence on logical empiricism came from thinkers such as Bertrand Russell , Ludwig Wittgenstein and Ernst Mach . So the logical empiricism represents z. B. a strictly anti-metaphysical attitude which he shares with the original empiricism and also with the empirically oriented immanence positivism.
At the same time, the positions of these forerunners were critically questioned and reviewed. For example, Schlick criticized Mach's immanence positivism very early in the 1920s. At that time, Schlick advocated epistemological realism, since it was only possible to gain meaningful scientific knowledge if one can also accept as real things that are not given. At the latest after the protocol sentence dispute at the beginning of the 1930s, the term "immediately given", which is decisive for positivism, was abandoned and fallibilism was accepted instead . Nevertheless, the logical empiricists continued to see themselves in the tradition represented by E. Mach and continued to use the term positivism in a much broader sense for themselves.
The name "logical empiricism" goes back to Hans Reichenbach, who suggested this name as an alternative to the name "logical positivism" used by Herbert Feigl. Other less well-known suggestions were "Consistent Empiricism" (M. Schlick) or "Scientific Rationalism" (O. Neurath).
Usually no distinction is made between the expressions logical empiricism and logical positivism . If a factual distinction is made, logical empiricism is the broader term. The logical positivism is then u. a. conceived as “an important current” of logical empiricism. Historically, members of the Berlin Circle did not use the term positivism for themselves.
One of the main concerns of logical empiricism was to be able to specify precise criteria according to which one can judge philosophical methods as valid or invalid. An important motive for this was the comparison between the development of empirical sciences and mathematics on the one hand and philosophy on the other. While in the former there has been an undeniable increase in knowledge in the last few centuries, from the point of view of the logical empiricists such a progress could be contested in many essential areas of philosophy - despite millennia of tradition. In addition to the communication problem , the lack of criteria for assessing philosophical methods that were as precise as possible was made responsible for this discrepancy . Due to the lack of such compelling criteria as exist in mathematics and natural sciences, no agreement has been reached on the essential philosophical questions to date.
The model of logical empiricism was the logicism Gottlob Freges . Similar to how a program was set up there that tried to reconstruct mathematics in the context of logic, a program was set up in logical empiricism that had the aim of rationally reconstructing the theories of the empirical sciences with the help of logic. Logical empiricism required that all meaningful statements can either be reduced directly to observation sentences, or at least can be brought into a logical relation to observation sentences so that they can be confirmed or checked by accepted observation sentences. The accepted observation sentences are seen as an intersubjective agreement, not as an absolutely secure basis, although they are not denied an objective content. Contrary to some receptions, which assume a traditional epistemological fundamentalism to logical empiricism, which wanted to base secure knowledge on observational propositions that are considered absolutely certain, it is emphasized today that logical empiricism especially in the form as developed by the main representatives Moritz Schlick , Rudolf Carnap and Otto Neurath was promoted, contained an epistemological anti-fundamentalism, which also rejected the view of (scientific) philosophy as a privileged and autonomous authority for the evaluation of scientific knowledge and procedures.
Development and expansion
The Vienna Circle, a weekly meeting of discussion groups that developed in 1923 from a seminar by Moritz Schlick, is considered to be the source of logical empiricism. This group was characterized by its interdisciplinary composition. The participation of R. Carnap, who was appointed to the University of Vienna in 1926 and was to become one of the best-known figures of logical empiricism, was decisive for the development of the Vienna Circle. In addition to Carnap's book The Logical Structure of the World , Wittgenstein's Tractatus Logico-Philosophicus in particular can be mentioned as an influential inspiration at this early period .
In 1928, a similar group was founded in Berlin as the Berlin Society for Empirical Philosophy , including Hans Reichenbach as a leading member. There was also a collaboration between the Vienna Circle and a group around Heinrich Scholz in Münster. Similar groups also formed outside of the German-speaking area, for example the Lemberg-Warsaw School in Poland , a group directed against irrationalist metaphysics, of which Alfred Tarski was one of the most famous members . In Scandinavia, Axel Hägerström founded the Uppsala School as early as 1910 , which anticipated some of the conceptions of later logical empiricism, but only came into contact with the Vienna Circle relatively late, in the 1930s. The Hägerström student Konrad Marc-Wogau and the magazine Theoria formed an important Scandinavian connection to Viennese positivism.
In addition to these groups there are numerous individuals from different countries who can be counted as part of logical empiricism. These include the Scandinavians Eino Kaila , GH von Wright , Arne Næss , Joergen Joergensen , the British Joseph Henry Woodger and Alfred Jules Ayer , the Swiss Ferdinand Gonseth and Karl Dürr ; as well as Louis Rougier from France and the German Paul Oppenheim .
The Vienna Circle first appeared in public in 1929 with a publication entitled "Scientific World Conception: The Vienna Circle". in which the program of the Vienna Circle was explained. This was published by the Ernst Mach association founded in 1928 with the aim of promoting and disseminating a scientific worldview .
Already since the 1920s there has been a lively exchange of ideas between members of the Vienna Circle and American philosophers, and in the 1930s almost all representatives of logical empiricism emigrated from German-speaking countries, most of them to the USA. The reasons for this were partly economic reasons or - as in the case of R. Carnaps - a call to the University of Chicago, but mostly political reasons. Many representatives of logical empiricism were Jews and had to leave the Nazi regime due to rampant anti-Semitism. Many representatives were also active in left or liberal movements and came into conflict with clerical Austrofascism and National Socialism . The consequence of this was a dominant position of logical empiricism in the philosophical faculties of American universities.
With the murder of M. Schlick in 1936 by his former student Hans Nelböck , the Vienna Circle dissolved. With this, logical empiricism also disappeared in the German-speaking area, where it was essentially developed. Only after the Second World War were u. a. of W. Stegmüller of logical empiricism in the form of the essential core idea analytical philosophy reintroduced in Germany.
Link to American pragmatism
With its relocation to North America, logical empiricism entered into a connection with American pragmatism in terms of content and personnel . Leading pragmatists like Charles W. Morris and John Dewey were co-editors of the International Encyclopedia of Unified Science alongside Rudolf Carnap and others . This connection was facilitated by many parallel ideas, for example those of fallibilism , which were found in both philosophies. Ultimately, however, differences over the position of objectivity in science stood in the way of a complete amalgamation of both directions; although here, too, some logical empiricists, such as O. Neurath, took positions that came very close to those of the pragmatists.
The time of the Vienna Circle was a time of great social and scientific upheaval. The emerging logical empiricism also saw itself as a revolutionary movement that wanted to overcome the traditional philosophy, just as relativity theory and other new physical theories had overcome the physical worldview that was valid up to that point.
The revolutionary impulse was not limited to philosophy, however; contrary to today's widespread perception, many representatives of early logical empiricism were strongly politicized and linked to other progressive groups. The American science historian Don Howard compares their position in the left and left-liberal political spectrum of the time with the position of the representatives of the Frankfurt School or Jean-Paul Sartre in the post-war left. Particularly exposed here was the sociologist Otto Neurath , who was President of the Central Economic Office in the Bavarian Council Republic , who politically represented a non-dialectical Marxism and, after the First World War, was one of the best-known intellectuals with strong connections to the Austro - Marxist Austrian social democracy. Neurath in particular saw logical empiricism not only as a purely scientific matter. For him, the new philosophy of science, for example as a philosophical counterpart to the movement for new objectivity , was part of a progressive, comprehensive movement. Phillip Frank, Hans Hahn, Edgar Zisel and Rudolf Carnap are also considered members of the “left wing” of the Vienna Circle, while Moritz Schlick, Friedrich Waismann, Karl Menger and Felix Kaufmann took more individualistic, liberal positions. In his youth, H. Reichenbach was chairman of the Socialist Student Party in Berlin , and the Berlin Society for Empirical Philosophy, which he carried with him, had a left-liberal orientation.
This political tendency earned logical empiricism violent hostility from conservative and right-wing circles, which ultimately led to the expulsion of the new scientific-theoretical direction from Central Europe during the time of National Socialism and to its almost complete relocation to North America. But left circles also attacked the new epistemological direction; For example, the neo-Marxist Max Horkheimer attacked logical empiricism in 1937 because of its hostility to metaphysics.
After the Second World War, logical empiricism was largely depoliticized. The reason given for this is the loss of the cultural background (“Weimar culture”) and the professionalization and establishment of logical empiricism in the academic world. The death of O. Neurath as the driving force of the radical left in the Vienna Circle in 1945 and the fact that with Phillip Frank only one representative of the radical left in the Vienna Circle emigrated to North America played a role here. In addition, the anti-communism of the McCarthy era is assigned a role; this is how Phillip Frank came into the sights of the FBI during this time . Despite this depoliticization of logical empiricism as a movement, some representatives continued to be politically active on an individual basis; R. Carnap traveled to Mexico a few months before his death to support imprisoned communist philosophers, and Carnap's last known photo shows him in the company of human rights activists.
Several series of works were published by the representatives of logical empiricism. To the days of the Vienna Circle the ranks "were unified science " and " writings on the scientific world view " was published, while the International Encyclopedia of Unified Science was published after resolution of the Vienna Circle in the English-speaking world.
In 1930 H. Reichenbach and R. Carnap took over the journal Annalen der Philosophie as editors and continued it under the name Knowledge as an important publication organ of logical empiricism. This magazine was discontinued in 1939 as a result of the Second World War. Realization was 1975, u. a. by W. Stegmüller, re-established as a publication forum for analytical philosophy.
Logical empiricism is a variant of modern empiricism. It saw itself as a “reform movement” and is seen as a “school” that has - critically - attested to “a specifically religious, even sectarian” attitude.
Attempts at labeling
Logical empiricism is not a “unified philosophical position”. There are different attempts to characterize logical empiricism, including:
Wolfgang Detel characterizes logical empiricism as follows:
- “(1) The principles of classical semantics apply.
- (2) All knowledge ... must ultimately be traced back to perceptions ... and observational sentences ...; this tracing must be formulated with the means of formal logic.
- (3) The formal logic presupposes bivalence ... and nominalism (...) (...).
- (4) The central task of philosophy is the semantic and logical analysis of everyday and scientific language in the form of analytical sentences (philosophy is understood as formal science ..., philosophy performs a linguistic turn). "
- In the Stanford Encyclopedia of Philosophy the following specific topics (are issues ) stated:
Rejection of synthetic a priori judgments
The representatives of logical empiricism agree that - contrary to Kant - there are no synthetic-a priori judgments and "all meaningful sentences are either analytical or synthetic".
The anti-metaphysical attitude of logical empiricism is linked to the so-called criterion of meaning . In its original, strict version, only statements that can be empirically verified were accepted as meaningful. For the logical empiricist, statements that do not meet this criterion are empirically meaningless and must be classified as metaphysical. For example, all statements about the existence of God are empirically meaningless. From this point of view, both an atheist and a theist are metaphysicians who make senseless claims.
For Carnap, the fact that there are metaphysical systems at all results from the fact that, in addition to science, there are also art and religion as human spiritual activities. For him, metaphysics is an unclear mixture of these three areas. For Carnap, metaphysicians are like artists without artistic talent who are unable to express their attitude to life in works of art and instead try completely inadequately to express their attitude to life in scientific language. In doing so, they are not doing anything useful for science, nor are they really able to express their attitude towards life, as gifted artists do, for example, by creating great works of art.
The originally strict empirical criterion of meaning has proven to be untenable, on the one hand due to the criticism of the verification method by Karl Popper , on the other hand because of the problems of theoretical terms discovered by Carnap . Carnap then developed a modified, more tolerant criterion of meaning that takes these criticisms into account. According to Stegmüller, this modified criterion of meaning is normative and independent of the rest of the instruments of logical empiricism. Thus, in principle, there is the possibility of either rejecting this criterion entirely or viewing it as a criterion of demarcation between metaphysics and the empirical sciences without declaring metaphysics as meaningless. This makes it possible to apply the methods developed by logical empiricism within rationalistic and metaphysical philosophical directions. As a result, there are currents in today's analytical philosophy , which has developed from logical empiricism, in which old metaphysical questions are treated again on a new basis.
On the basis of the anti-metaphysics of the circle, the abolition of the methodological separation of natural and human sciences in the concept of universal or unified science is called for.
A decisive unitary scientific moment is the common inductive method of generating knowledge: phenomena are experienced sensualistically and lead to hypotheses and theories (see sensualism ) through derivations . This creates levels of different concreteness that are worded differently. The phenomenal level is formulated in elementary sentences or protocol sentences. These alone are directly empirical and contain information that ensures the possibility of empirical reconstruction. They form the starting level for logical deductions in the generation of knowledge. The resulting hypotheses, theories and laws are therefore on the upper, more abstract level. This creates a theoretical network that is connected to the phenomenal level via points of contact.
The points of contact, the relationships between the elements and levels, determine the explanatory and predictive potential of the network and are expressed statistically, namely through correlations.
Unified science, especially by Neurath, is also defined as a cooperative research collective that communicates dynamically as a scholarly republic and agrees on the acceptance or rejection of hypotheses. Scientific knowledge generation is therefore understood as the formation of social, intersubjective consensus.
The protocol records are also subject to this consensus building and remain questionable. They can therefore not be regarded as a secure basis of knowledge. Because this conceptual moment, which basically puts the entire scientific system up for discussion, was mainly represented by Neurath, it is called the Neurath principle . (The corresponding engagement with the other circuit members - in particular with Schlick - on the role of log records was as protocol debate hereinafter).
The conception of the standardized science is based on the one hand on the connection of the specialist disciplines to standardized methodological principles, which are only recognized as generating knowledge. In addition, there is an epistemological reason for their conception: separately acting disciplines cannot map the complex field of conditions that determine worldly phenomena. Therefore they are not able to explain phenomena in their entirety. However, if this is to be a requirement, the linking of many theories from different disciplines in one unified science is imperative.
Critique and Decline of Logical Empiricism
The logical empiricism has been criticized many times. According to the dominant view today, it did not withstand the criticism. As a result, some speak of the “collapse” of logical empiricism and its “dissolution”. Logical empiricism has "hardly any followers today". Others do not fundamentally contradict this, but emphasize that elements of logical empiricism are still relevant. Which exactly is naturally controversial.
In 1967, John Passmore ( treating logical empiricism and logical positivism as synonyms) used a popular phrase: “Logical positivism, then, is dead, or as dead as a philosophical movement ever becomes.” (“Positivism is as dead as one philosophical movement it can only be. ").
According to today's consensus, these ultimately did not stand up to the fundamental criticism of Karl Popper and W. V. O. Quine . Whether the logical empiricism is refuted by further arguments is viewed (more) controversial in case of doubt.
Karl Popper had an ambivalent relationship to logical empiricism and the Vienna Circle . On the one hand, he was one of the sharpest critics of logical empiricism, on the other hand, he also saw allies against irrationalist currents in philosophy in his environment. Popper criticized the possibility of a verification method as logically refuted and opposed the falsification method. According to Popper's resumé in his famous polemic Against the Big Words , this criticism was later largely accepted by some members of the Vienna Circle.
W. V. O. Quine , originally a student of Rudolf Carnap, criticized logical empiricism from the position of radical empiricism. Above all, Quine criticized the (not only) in logical empiricism represented division of all true statements into synthetically true and analytically true statements, which he regarded as metaphysical elements. As a reaction to this point of criticism, Carnap introduced the so-called postulates of meaning . Another point of criticism from Quine is the view that empirical statements can be checked individually. For him, theory and language are inextricably linked, so when checking, a whole system of statements is always in question ( holistic naturalism ).
In a more recent monograph, Adrian Brücker also judges logical empiricism ultimately as inadequate, but defends it against central points of criticism of post-positivist analytical philosophy. Both the analytical / synthetic dichotomy and the assumption of the need to trace meaningful sentences back to a basis in phenomenal experience are very appropriate in a precisely spelled out form.
- Observation record (log record)
- Victor Kraft : The Vienna Circle, The Origin of Neopositivism. 3. Edition. 1950, 1968 and 1997 Springer-Verlag / Vienna, Verlag Springer, Vienna, New York, ISBN 3-211-82956-3 .
- Wolfgang Stegmüller : Main currents of contemporary philosophy, a critical introduction. Volume I. 7th edition. Kröner, Stuttgart 1989, ISBN 3-520-30807-X , Chapter IX: Modern empiricism: Rudolf Carnap and the Vienna Circle .
- Peter Achinstein , Stephen F. Barker: The legacy of Logical Positivism. Studies in the Philosophy of Science. The Johns Hopkins Press, Baltimore MD 1969, ISBN 0-8018-1014-0 .
- Rudolf Haller : Neopositivism. A historical introduction to the philosophy of the Vienna Circle. Scientific Book Society, Darmstadt 1993, ISBN 3-534-06677-4 .
- Nikolay Milkov (ed.): The Berlin group. Texts on logical empiricism by Walter Dubislav, Kurt Grelling, Carl G. Hempel, Alexander Herzberg, Kurt Lewin, Paul Oppenheim and Hans Reichenbach. Meiner, Hamburg 2015.
- Friedrich Stadler : Studies on the Vienna Circle. Origin, Development and Effect of Logical Empiricism in Context. Suhrkamp, Frankfurt am Main 1997, ISBN 3-518-58207-0 . 2nd edition by Springer, Dordrecht 2015.
- Michael Stöltzner, Thomas Uebel (Ed.): Vienna Circle. Texts on the scientific worldview. Meiner, Hamburg 2006, ISBN 3-7873-1811-9 .
- Payne: Logical Positivism
- Richard Creath: Logical Empiricism. In: Edward N. Zalta (Ed.): Stanford Encyclopedia of Philosophy .
- Matthias Neuber: Freedom from dogmas as a principle? Newer literature on logical empiricism (PDF; 164 kB), Journal for Philosophical Research, Volume 65 (2011), 96–114
- Wolfgang Stegmüller therefore describes the characterization of logical empiricism as positivism as inapplicable and demanded that the corresponding designations no longer be used. He justified this with the fact that, on the one hand, there was no uniform philosophical doctrine within the Vienna Circle; there was only agreement on the demand for a scientific attitude that was as exact as possible. Furthermore, only those directions are designated as positivistic which - such as Mach - start from the directly given .
- In his review of K. Poppers “ Logic of Research ”, R. Carnap explains that the sense in which the term “positivism” is used by logical empiricism for itself is very broad. In fact, they would classify all positions as positivism in which the acceptance of theories would ultimately come about through confrontation with reality, whereby even Popper's position would still fall under this broad concept of positivism.
- Albert E. Blumberg, Herbert Feigl: Logical Positivism: A new Movement in European Philosophy. Journal of Philosophy 28, 281-296 (1931)
- see introduction to "Logical Empiricism in North America." GL Hardcastle, AW Richardson (editors), Minnesota Studies in the Philosophy of Science, XVIII, (2003)
- So Richard Creath: Logical Empiricism. In: Edward N. Zalta (Ed.): Stanford Encyclopedia of Philosophy .
- Greimann, Dirk: The logical empiricism and its dissolution in the American post-war philosophy . In: E. Fischer / W. Vossenkuhl: The questions of philosophy. Beck, Munich 2003, p. 346 (351)
- Richard Creath: Logical Empiricism. In: Edward N. Zalta (Ed.): Stanford Encyclopedia of Philosophy .
- Thomas E. Uebel: Anti-Foundationalism and the Vienna Circle's Revolution in Philosophy. Brit. J. Phil. Sci., 47, (1996), 415-440
- Scientific world view: The Vienna Circle ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- see some CW Morris Logical Positivism, Pragmatism, and Scientic Empiricism. Paris 1937.
- Don Howard Two Left Turns Make a Right: On the Curios Political Career of North American Philosophy of Science at Midcentury. in Logical Empiricism in North America. GL Hardcastle, AW Richardson (editors)
- FK Stadler Transfer and Transformation of Logical Empiricism. in Logical Empiricism in North America. GL Hardcastle, AW Richardson (editors)
-  Karl-Peter Schwarz : The end of the Vienna Circle: "So dog, now you have it"
- Steve Awodey, Carsten Klein: Carnap Brought home: the view from Jena. Open Court (2004), ISBN 0-8126-9551-8 , p. 35.
- Detel, Wolfgang: Basic Course Philosophy IV: Epistemology and Theory of Science. Reclam, Stuttgart 2007, p. 55.
- Greimann, Dirk: The logical empiricism and its dissolution in the American post-war philosophy . In: E. Fischer / W. Vossenkuhl: The questions of philosophy. Beck, Munich 2003, p. 346.
- Chalmers (1999/2007), Wissenschaftstheorie, p. 7 (for logical positivism ); IM Bocheński, European Philosophy of the Present , Tübingen, Basel, Francke, 3rd edition (1994), p. 66 (for neopositivism)
- IM Bocheński: Contemporary European Philosophy. 3. Edition. Francke, Tübingen, Basel 1994, p. 66.
- Russ, Hans Günther: Theory of Science, Epistemology and the Search for Truth. Kohlhammer, Stuttgart 2004, p. 58.
- Wolfgang Detel : Basic Course Philosophy IV: Epistemology and Theory of Science. Reclam, Stuttgart 2007, p. 56.
- Creath, Richard: Logical Empiricism. The Stanford Encyclopedia of Philosophy (Spring 2014 Edition), Edward N. Zalta (ed.), URL =
- Russ, Hans Günther: Theory of Science, Epistemology and the Search for Truth. Kohlhammer, Stuttgart 2004, p. 58.
- Detel, Wolfgang: Basic Course Philosophy IV: Theory of Knowledge and Science. Reclam, Stuttgart 2007, p. 56: "Core Thesis".
- Neurath, Otto (1931): Physicalism: The Philosophy of the Vienna Circle. In: ders .: Collected, philosophical and methodological writings 1. Ed. Haller, Rudolf / Rutte, Heiner. Vienna 1981, p. 416.
- Neurath, Otto (1936): The encyclopedia as a model. In: ders .: Collected, philosophical and methodological writings 2nd ed. Haller, Rudolf / Rutte, Heiner. Vienna 1981, p. 733.
- Neurath, Otto (1930): Uniformity of the objects of all sciences. In: ders .: Collected, philosophical and methodological writings 1. Ed. Haller, Rudolf / Rutte, Heiner. Vienna 1981, p. 394.
- Geier, Manfred: The Vienna Circle. Reinbek near Hamburg 1995, p. 74.
- Tschamler, Herbert: Theory of Science. An introduction. Munich 1977, p. 44f.
- Haller, Rudolf: Neopositivism. A historical introduction to the philosophy of the Vienna Circle. Darmstadt 1993, pp. 71, 160.
- Neurath, Otto (1928): Lifestyle and Class Struggle. In: ders .: Collected, philosophical and methodological writings 1. Ed. Haller, Rudolf / Rutte, Heiner. Vienna 1981, p. 279.
- Haller, Rudolf: History and scientific system with Otto Neurath. In: Berghel, Hal u. a. (Ed.): Wittgenstein, the Vienna Circle and critical rationalism. Vienna 1979, p. 304ff.
- Neurath, Otto (1932/33): Protocol sentences. In: ders .: Collected, philosophical and methodological writings 2nd ed. Haller, Rudolf / Rutte, Heiner. Vienna 1981, p. 579.
- Haller, Rudolf: History and scientific system with Otto Neurath. In: Berghel, Hal u. a. (Ed.): Wittgenstein, the Vienna Circle and critical rationalism. Vienna 1979, p. 305.
- Neurath, Otto (1931): Empirical Sociology. In: ders .: Collected, philosophical and methodological writings 1. Ed. Haller, Rudolf / Rutte, Heiner. Vienna 1981, p. 434.
- Uebel, Thomas: Critique of Reason and Science. Otto Neurath and the first Vienna Circle. Vienna / New York 2000, p. 50.
- Hans-Johann Glock : What is analytical philosophy? WBG (Scientific Book Society), Darmstadt 2014, ISBN 978-3-534-25496-5 , pp. 58-62: The collapse of logical positivism. ; similar: Moulines, Carlos Ulises: The development of modern philosophy of science (1890-2000). Hamburg, Lit 2008, p. 75: The collapse of positivism.
- See the title: Greimann, Dirk: The logical empiricism and its dissolution in the American post-war philosophy . In: E. Fischer / W. Vossenkuhl: The questions of philosophy. Beck, Munich 2003, p. 346 ff.
- Saporiti, Katia: Empiricism. In: Jordan / Nimtz (Ed.): Lexicon Philosophy: Hundred Basic Concepts. Reclam, Stuttgart 2009, p. 73 (75)
- Creath, Richard: Logical Empiricism. The Stanford Encyclopedia of Philosophy (Spring 2014 Edition), Edward N. Zalta (ed.), URL =: Kapitel Impact
- Quoted in Popper and in Creath, Richard: Logical Empiricism. The Stanford Encyclopedia of Philosophy (Spring 2014 Edition), Edward N. Zalta (ed.)
- Passmore, J .: 1967, Logical Positivism, ”The Encyclopedia of Philosophy (Volume 5). P. Edwards (ed.), New York: Macmillan, 52 (57), quoted from Creath, Richard, Logical Empiricism. The Stanford Encyclopedia of Philosophy (Spring 2014 Edition), Edward N. Zalta (ed.), URL =
- Moulines, Carlos Ulises: The Development of Modern Philosophy of Science (1890-2000). Hamburg, Lit 2008, p. 60 (speaking about modern philosophy of science, meaning logical empiricism).
- Hans-Johann Glock : What is analytical philosophy? WBG (Scientific Book Society), Darmstadt 2014, ISBN 978-3-534-25496-5 , p. 61.
- "... In this new preface I intend to explain my attitude towards the present situation, and the two main schools of language analysis today. Now as then, language analysts are important to me; not only as opponents, but also as allies, in so far as they seem to be almost the only philosophers left who keep alive some of the traditions of rational philosophy. “from the preface to the first english edition of Popper's The Logic of Scientific Discovery (1959)
- W. V. Quine Two Dogmas of Empiricism 
- Adrian Brücker: Language, Knowledge and Science. A fundamental analysis of the possibilities and requirements of knowledge and the logical stages of the knowledge process, Volume 1: Knowledge and meaning. Bouvier, Bonn 2017, ISBN 978-3-416-04017-4 .
- Brücker sees a central weakness of logical empiricism in the underestimation of persistent skeptical problems, which are expressed above all in the highly theoretical character of normal language terms and sentences, with the result that the truth conditions of these sentences are very complicated in relation to unreal conditionalities counterfactual perceptions depended in counterfactual circumstances. Logical empiricism “failed to bring back the travel-physicalistic thing-language satisfactorily to the directly perceived sensory data or phenomena” (Ibid., P. 733), although such a program is by no means doomed to failure in principle.