Is rationalism unfounded

Sir Karl Popper, the theorist of open thinking, was born in Vienna 100 years ago: The philosopher of rationalism

Popper's great response is due not least to the fact that he differed from (almost) all other philosophers in more ways than one. He always started from pressing problems and tried to present his problem analyzes and proposed solutions as clearly and simply as possible. What he wrote was very deliberately not "professorial philosophy for philosophy professors". He distrusted words and kept most discussions about definitions or the meaning of words for wasted time. He believed that all great philosophy consisted in an attempt to solve problems that arose outside of philosophy, and he saw the very special responsibility of intellectuals to be to present their results in the simplest, clearest and most humble form. Everything you investigate is complex, but "everything that can be said in a finite life and with as few words as possible is simple things that nevertheless shed light on the world around us: the more light and the simpler , the better". And further: "incomprehensibility has its cause either in incompetence or the attempt to impress people with words", in which Popper saw a violation of the elementary moral imperative of intellectual honesty.

A thinker for realists

There were and are philosophically awake non-philosophers, especially natural scientists, who are the sounding board for Popper's ideas, because when reading Popper they have the feeling that their cause is being negotiated here: someone who, like most natural scientists, was a realist, is speaking and has made contributions to individual sciences himself.

Natural scientists were Popper's preferred discussion partners: Niels Bohr, Albert Einstein, Erwin Schrödinger, John Eccles, Peter Medawar, Jaques Monod, Konrad Lorenz, Max Perutz - to name, somewhat arbitrarily, only those who were awarded Nobel Prizes. Popper has always considered it the greatest of his countless awards that Niels Bohr and Albert Einstein came to his seminar lecture on "Indeterminism in Classical Physics and Quantum Theory" at Princeton and discussed them with him when everyone else had long left. (The extraordinary diversity of the problems discussed by Popper leads - as recently once again at the Popper Congress in Vienna - to "segregation phenomena" among the participants: the experts in quantum logic have little to contribute to the interpretation of the writings of the pre-Socratics - and vice versa) .

For today's natural scientists, it is above all Popper's methodology that they recognize in their work: the central role of the problem and the analysis of the problem situation, the irrelevance of the way in which one comes to a proposal for the solution of the problem, and the worlds that lie between a hypothesis that cannot be empirically tested (and therefore, in Popper's sense, metaphysical) and an empirically refutable or even already refuted hypothesis. Under the impression of the overwhelming success of their research methodology, they are - like Popper - convinced that of two theories, the one with the greater empirical content is to be preferred. And they - like Popper - have no qualms about the assumption that the second theory comes closer to truth in a certain sense, even if, like all other people, they cannot offer a criterion with which to diagnose the existence of truth could. They experience more directly than others that absolutely certain (or justified) knowledge is beyond the reach of their method - even if they had worked out a true theory, they could not prove it.

Popper's epistemology builds - in the tradition of Kant - on Albert Einstein's refutation of Newtonian mechanics and Einstein's theory of knowledge. In his intellectual autobiography "Starting points", Popper described how he came to his criterion for the delimitation of empirical scientific theories from other scientific theories or pseudosciences and to his "solution" to the induction problem. The Israeli historian of ideas Malachi Haim Hacohen showed with his extraordinary analysis of the development of Popper's thinking published two years ago that Popper presented his intellectual development in the light of his later thinking in his autobiography. Philosophy historians such as Friedrich Stadler point out today that Popper's interactions with philosophers from the Vienna Circle were much more intense than the "starting points" suggest, but that does not change the fact that Popper's devastating criticism of verification was the decisive one The criterion for distinguishing meaningful from meaningless sentences was, which is generally accepted today and has given the critical discussion of metaphysical ideas their weight again.

Forced emigration

Just as Popper's work on problems in the field of statistics, quantum physics and epistemology was about to gain international recognition, it was abruptly interrupted by the need to flee from the National Socialists. Emigration took him to Christchurch in New Zealand in March 1937, at that time still cut off from the world - for Hennie, his self-sacrificing wife, "halfway to the moon": 100,000 residents, normal mail to Europe and the USA all three Months, sometimes airmail via Australia, which took three weeks. Canterbury College had about 100 students at the time and its library had about 15,000 books - about as many as Popper's father had at Farmers Market 1. 40 of them dealt with philosophical questions and had appeared in the 20th century, the youngest was not even older than 10 years.

There he completed - as he wrote, "neither by training nor by inclination to be a social or political scientist" - the first version of his book "The misery of historicism" and wrote in the years from 1938 to 1942 "The open society and their enemies ". In this analysis of the roots of every kind of totalitarianism Popper saw his contribution to the struggle against fascism and totalitarian socialism, written against the background of his political experiences in the interwar years in Vienna. He saw in fascist movements a trend back to a closed society, born out of fear of change, prepared in the totalitarian traits of the philosophy of Plato and Hegel. In contrast, Marx and the socialists seemed to him to be in the progressive camp, burdened by their ambivalent attitude with regard to the legitimation of the use of force and their supposedly "science" based belief in historical processes, which was not only unfounded, but weakened the ability of European democracies to resist totalitarian fascism and totalitarian communism effectively.

Theory of democracy

With the exception of a few very prominent scientists and historians - such as Bertrand Russel or Gilbert Ryle - the experts reacted largely negatively: most of them did not recognize "their" Plato and "their" Hegel in Popper's reconstruction of the problem situation, and many Marxists kept the book - especially when it was later read in the light of the Cold War - for a frontal attack launched with transparent motives. On the other hand, however, stood the extremely positive reaction of the general public: The book has been reprinted for almost 50 years and has been translated into more than 30 languages. A discussion about the theory of democracy, about Plato or Marx would not be up to date today without going into what Popper wrote about it in the "Open Society". This book has also been called a pillar of the philosophy of social democracy - a philosophy of constantly revised changes in a democratic society in a rational and humane way.

After moving to the London School of Economics in 1947, Popper returned to his old field of work. The following decades were extremely fruitful scientifically. All the works on quantum theory, determinism and indeterminism, realism and the goal of science, scientific revolutions and the philosophy of mind, his "three worlds theory" and his theory of the evolutionary growth of knowledge in all its facets were created - works, which today make up the second focus of his scientific fame.

Critical Rationalism

What Popper, his students and colleagues worked out is usually summarized today under the name "critical rationalism" and is the most modest form of knowledge: the result of the insight into the fallibility of knowledge and the possibility of learning from mistakes, which lives everywhere wherever there is institutionalized critical discussion.

Popper's critical rationalism will remain all the more important, the more urgent the new, extra-philosophical problems that are taken up in his mind. His "Open Society" is a utopia that real societies only approach to a certain extent. Just a few years ago, this extent was greater than it is today - at a time when problems were networked around the world, when the clash of different cultures is perceived not as an opportunity but as a threat, and when violence threatens to become respectable again as a means of politics; a time in which peaceful attempts to solve problems, such as long-term negotiated international treaties, are terminated or not ratified and the life chances of people in poor and rich countries are destroyed by forms of the capital market that have gotten out of hand. Popper's life and philosophy can be encouraging: despite everything, he remained an optimist.

Sir Karl Popper 1902 to 1994

1902 Karl Raimund Popper was born on July 28th in Ober St. Veit (Vienna).

1918/19 work with socially vulnerable children at Alfred Adler; short term communist.

1922 apprenticeship as a carpenter; Matriculation examination.

1924/25 completed his apprenticeship as a carpenter; Teaching examination for elementary schools.

1928 PhD.

1929/30 teaching examination for secondary schools; Contact with members of the Vienna Circle. The first book: "The two basic problems of epistemology".

1930 employed as a secondary school teacher; Marriage to Josefine Anna Henninger.

1934 "The Logic of Research".

1937 emigrated to New Zealand; Lecturer at Canterbury University College;
1938 - 1943 Creation of "The Open Society and its Enemies" (published 1945); (German: "The open society and its enemies").

1943/1944 publication of "The Poverty of Historicism" (as a book 1957, German: "Das Elend des Historizismus").

1946 ao. Professor at the London School of Economics (LSE).

1949 professor at the LSE.

1963 "Conjectures and Refutations." (German: "Assumptions and Refutations", 1994).

1965 "Sir" Karl Popper.

1969 retirement.

1972 "Objective Knowledge: An Evolutionary Approach". (German: "Objective Knowledge: An Evolutionary Design").

1974 autobiography "Unended Quest." (German: "starting points").

1985 Josefine Popper dies.

1994 Popper dies.