Popper in 60 Minutes E-Book

Walther Ziegler

• Herausgeber: Books on Demand
• Kategorie: Geisteswissenschaft
• Sprache: Englisch
• Veröffentlichungsjahr: 2020

Seitenzahl: 78

Beschreibung

Karl Popper (1902-1994) is one of the great thinkers of the modern age. He developed his key idea, the "open society" already at age 17. Popper at the time believed passionately in Newton's theory of gravitation, by which the science of the day explained the motion of all bodies on earth and in the heavens. But during the great eclipse of 1919 observations were made that confirmed for the first time Einstein's theory of relativity. The London Times wrote: "Scientific Revolution; New Theory of the Universe; Newton's Conception Overthrown." If this is so, concluded Popper, and if a genius like Newton can prove to have been wrong and his knowledge, after two hundred years, can be replaced by a better knowledge, then perhaps there are no such things as truths "true once and for all". It was at this point that he developed his brilliant key idea: "Scientific knowledge is not knowledge; it is only conjectural knowledge." Every scientific theory must count as "true" only for so long as it cannot be refuted by some counter-example or replaced by a better theory. And just for this reason modern society must always be open to critiques and new theories. This applies also, indeed quite especially, to politics. Instead of calling, like Plato, for an ideal state, or pursuing, like Marx and Hegel, "totalitarian" philosophical-historical goals, the scientific method of trial and error must also be applied to politics. Was Popper right? Is all our knowledge merely conjectural knowledge resting on trial and error? And did Plato, Hegel and Marx really pave the way for totalitarianism? Is what we need to improve society really rather the method of "hard science"? Can we solve our problems using Popper's "piecemeal social technology"? Popper gives clear and unmistakable answers. The book appears as part of the popular series "Great Thinkers in 60 Minutes".

Leseprobe

My thanks go to Rudolf Aichner for his tireless critical editing; Silke Ruthenberg for the fine graphics; Lydia Pointvogl, Eva Amberger, Christiane Hüttner, and Dr. Martin Engler for their excellent work as manuscript readers and sub-editors; Prof. Guntram Knapp, who first inspired me with enthusiasm for philosophy; and Angela Schumitz, who handled in the most professional manner, as chief editorial reader, the production of both the German and the English editions of this series of books.

My special thanks go to my translator

Dr Alexander Reynolds.

Himself a philosopher, he not only translated the original German text into English with great care and precision but also, in passages where this was required in order to ensure clear understanding, supplemented this text with certain formulations adapted specifically to the needs of English-language readers.

Inhalt

P

opper’s Great Discovery

Popper’s Central Idea

Popper’s Revolutionary Theory of Knowledge: Science as Merely Provisional Truth

Deduction Instead of Induction:

“A Human Being is not a Bucket”

Open and Closed Societies

The “Open Society” Instead of Plato’s “Government by the Best”

The False Prophets Hegel and Marx

Critical Rationalism as Constant Renewal of Knowledge and Society

Of What Use is Popper’s Discovery for Us Today?

Popper’s Notion of the “Step-by-Step Improvement of Life”

Is Popper Right? Did Plato, Hegel and Marx Prepare the Way for Totalitarianism?

The Positivism Dispute: Critical Rationalism Instead of Critical Theory?

Popper’s Legacy: All Life is Problem-Solving

Bibliographical References

Popper’s Great Discovery

Karl Popper (1902-1994) is indisputably one of the truly great thinkers of the modern age. At once scholar of the natural sciences and philosopher of society, he has left a profound and decisive mark both on the theory of scientific knowledge and on our political and social self-understanding.

Born in Austria, he spent most of his professional life as a professor of philosophy in London, where he acquired, in 1949, British citizenship. In 1965 he was even knighted by the Queen. When Sir Karl Popper died at the age of 92 he was celebrated as “the philosopher of the 20th century” and as the last in the row of the great men of the Enlightenment. The key idea which was later to bring him world renown he developed already as a 17-year-old in the city of his birth, Vienna. He counts, indeed, along with Rousseau and a handful of others, as one of those exceptions among philosophers whose key notions suddenly come to them in perfect clarity, as a sort of epiphany or moment of sudden sublime insight, in their most tender years. Paradoxically, the moment of “illumination” in Popper’s case was a moment of sudden darkness, namely, a solar eclipse:

This solar eclipse of 1919 and the photographs taken of it by the British astronomer Eddington became, for Popper, a turning point in his life. Whereas he had been, up until then, a passionate adherent to the views of Newton, whose theory of gravitation he considered to be irrefutably true, he was now forced to entirely rethink his position. Because it was Eddington’s photos of the positions of two particular stars that enabled Einstein to offer, for the very first time, real-world evidence of the truth of his revolutionary new theory of relativity.

In the celestial mechanics developed by Newton space is only a sort of receptacle which the various celestial bodies traverse, as time elapses, in perfectly straight lines. That a planet like Earth nonetheless takes a circular course around the sun is, according to Newton, due to the attraction of the “gravitational force” existing between sun and Earth. For Einstein, on the other hand, space and time are not independent magnitudes but rather blend together into a geometrical, four-dimensional continuum that Einstein referred to as “spacetime”, this “spacetime” being the true cause of the curvature of the courses followed by all celestial bodies. The spacetime continuum, claimed Einstein, can even bend light and for this reason, he went on, it is possible to see in the night sky on certain days, such as the day of the eclipse on that 29th of May, stars which are in fact located far behind the sun and which ought, therefore, not to be visible. While the moon passes, for some minutes, directly in front of the sun and darkens the latter’s brightness it is even possible to take photos of these stars. Through such photos, Einstein recognized, his theory of relativity would be either proven or dis-proven and Einstein even invited other researchers to proceed to such a real-world testing of his claims.

Though in that year of 1919 hostilities had barely ended between Germany and Great Britain, it was the latter country that mounted two expeditions to carry out this, the German physicist’s wish. One of these was led by Eddington. And lo and behold, the photos taken by Eddington’s expedition did indeed show the stars in question to be in positions that confirmed Einstein’s hypothesis of a “curvature of spacetime” and not in those that they would, had the Newtonian gravitational theory held true, be expected to be in. Also according to this latter theory, indeed, the light of the stars in question would have succeeded in bypassing the sun; but this light would have been perceptible at quite other points and with a much smaller deviation.

In divergence from these Newtonian expectations, Einstein had predicted, on the basis of his idea of a curvature of spacetime, that the light-rays of the stars in question would undergo a deflection of 0.83 arc-seconds. And the measurements taken by Eddington turned out indeed to coincide astonishingly precisely with this prediction. This made Einstein a superstar of science overnight. The London Times headlined “Scientific Revolution. New Theory of the Universe. Newton’s Conception Overthrown.” The headline was no exaggeration because since Newton’s founding, with his groundbreaking Philosophiae Naturalis Principia Mathematica of 1687, of classical mechanics and modern physics, everyone had believed that the key to the movement of physical bodies on the earth and the course of celestial bodies beyond it had once and for all been found. Now, however, the world in general, and Popper in particular, found they had to think again:

If this is indeed the case, if even a genius like Newton could be wrong and his knowledge could have to be replaced after two hundred years by a better knowledge, then, so thought Popper, perhaps there are no such things as truths found “once and for all” at all. It was just at this point that Popper conceived his brilliant central idea:

He formulates, indeed, this idea in still more radical terms:

The reason for this is not that Newton and other scientists did sloppy or methodologically imprecise work. It is rather a matter of the most basic and essential characteristics of the processes by which truth is discovered in the sciences. Popper’s great discovery was that scientific knowledge consists, in principle, just in a series of ever-renewed hypotheses and models of explanation which count as true hypotheses and models only for so long as no counterexample, or no better model of explanation, has been found. With this discovery Popper placed in question the notion generally accepted by his contemporaries that scientific theories could be definitively proven by conducting series of experiments. Because, as Popper argued, even if a scientist succeeds in finding in the real world a thousand examples and proofs of the theory he is advancing, it is always possible that a counter-example will turn up and throw everything back into question. In his main work on the theory of the sciences, The Logic of Scientific Discovery of 1932, he illustrates this idea by the famous example of the swan:

Popper is referring here to an item of supposed knowledge that had been accepted for centuries. Swans had been known in Europe since earliest times and always as a large bird with white plumage. For centuries, therefore, the sentence “all swans are white” had counted as an example of evident truth. When Europeans first came to Australia, however, they were amazed to discover a type of swan with black plumage. That long-established textbook example of a true proposition to the effect that “all swans are white” was suddenly proven to be false or, as Popper puts it, was “falsified”.

“Falsification”, indeed, is the concept that is key to understanding of Popper’s theory of science. Scientific progress, so runs his provocative thesis, does not rest, as so many of his contemporaries believed it did, on induction: i.e. on the logical derivation of regularities from knowledge acquired by experiment. On the contrary, it rests on theoretical hypotheses and on these latter’s “falsification” once they have been advanced. As soon as a hypothesis has been proven false by the emergence of a counter-example to whatever it advances, it must be replaced by a new and better hypothesis – a process which leads us, over the long term, closer and closer to truth. This process of drawing ever closer is the core and the essence of scientific progress.

We may predict, with Popper, that even Einstein’s much-celebrated theory of relativity will count as true only until some better explanatory model is discovered. And where does this end? Might we arrive after all, even if only in ten or a hundred thousand years, at some final certainty, some definitive and absolute truth? Popper’s answer here is a sobering one. He cites the Pre-Socratic philosopher Xenophanes:

In a newspaper interview given toward the end of his life, Popper confessed: