O paradoxo de Karl Popper

segunda-feira, agosto 27, 2018

The Paradox of Karl Popper

The great philosopher, renowned for his ferocious attacks on scientific and political dogmatism, could be quite dogmatic

By John Horgan on August 22, 2018

Karl Popper said he was the happiest philosopher he knew. "Most philosophers are really deeply depressed," he explained, "because they can’t produce anything worthwhile.” Credit: LSE Library Flickr

The world has been paying lots of attention to philosopher Karl Popper lately, although surely not as much as he would think he deserves. Popper, 1902-1994, railed against dogmatism in all forms. He is best-known for the principle of falsification, a means of distinguishing pseudo-scientific theories, like astrology and Freudian psychoanalysis, from genuine ones, like quantum mechanics and general relativity. The latter, Popper pointed out, make predictions that can be empirically tested. But scientists can never prove a theory to be true, Popper insisted, because the next test might contradict all that preceded it. Observations can only disprove a theory, or falsify it. In The Open Society and Its Enemies, published in 1945, Popper asserted that politics, even more than science, must avoid dogmatism, which inevitably fosters repression. Open Society has been invoked lately by those concerned about the rise of anti-democratic forces. Popper’s falsification principle has been used to attack string and multiverse theories, which cannot be empirically tested. Defenders of strings and multiverses deride critics as “Popperazzi.” [See note below on spelling.] Given the abiding interest in this complex thinker, I am posting an edited version of my profile of Popper in The End of Science. Please also check out my profiles of two other great philosophers of science, Thomas Kuhn and Paul Feyerabend. –John Horgan

I began to discern the paradox lurking at the heart of Karl Popper's career when, prior to interviewing him in 1992, I asked other philosophers about him. Queries of this kind usually elicit dull, generic praise, but not in Popper’s case. Everyone said this opponent of dogmatism was almost pathologically dogmatic. There was an old joke about Popper: The Open Society and its Enemies should have been titled The Open Society by One of its Enemies. 

To arrange an interview, I telephoned the London School of Economics, where Popper had taught since the late 1940s. A secretary said he generally worked at his home in a London suburb. When I called, a woman with an imperious, German-accented voice answered. Mrs. Mew, housekeeper and assistant to “Sir Karl.” Before he would see me, I had to send her a sample of my writings. She gave me a list of a dozen or so books by Sir Karl that I should read before the meeting. After numerous faxes and calls, she set a date. When I asked for directions from a nearby train station, Mrs. Mew assured me that all the cab drivers knew where Sir Karl lived. “He’s quite famous.”

“Sir Karl Popper's house, please,” I said as I climbed into a cab at the train station. “Who?” the driver asked. Sir Karl Popper? The famous philosopher? Never heard of him, the driver said. He knew the street on which Popper lived, however, and we found Popper's home, a two-story cottage surrounded by neatly trimmed lawn and shrubs, with little difficulty.

A tall, handsome woman with short dark hair, wearing black pants and shirt, answered the door. Mrs. Mew was only slightly less forbidding in person than over the telephone. As she led me into the house, she told me that Sir Karl was tired. He had endured many interviews and congratulations brought on by his 90th birthday last month, and he had been toiling over an acceptance speech for the Kyoto Prize, known as Japan's Nobel. I should expect to speak to him for only an hour at the most.

I was trying to lower my expectations when Popper made his entrance. He was stooped and surprisingly short. I had assumed the author of such autocratic prose would be tall. Yet he was as kinetic as a bantamweight boxer. He brandished an article I had written for Scientific American about how quantum mechanics is raising questions about the objectivity of physics. “I don’t believe a word of it,” he declared in a German-accented growl. “Subjectivism” has no place in physics, quantum or otherwise, he informed me. “Physics,” he exclaimed, grabbing a book from a table and slamming it down, “is that!”

He kept jumping up from his chair to forage for books or articles that could buttress a point. Striving to dredge a name or date from his memory, he kneaded his temples and gritted his teeth as if in agony. At one point, when the word "mutation" eluded him, he slapped his forehead repeatedly with alarming force, shouting, “Terms, terms, terms!”

Words poured from him so rapidly and with so much momentum that I began to lose hope that I could ask my prepared questions. “I am over 90, and I can still think,” he declared, as if I doubted it. Popper emphasized that he had known all the titans of twentieth-century science: Einstein, Schrodinger, Heisenberg. Popper blamed Bohr, whom he knew “very well,” for having introduced subjectivism into physics. Bohr was “a marvelous physicist, one of the greatest of all time, but he was a miserable philosopher, and one couldn’t talk to him. He was talking all the time, allowing practically only one or two words to you and then at once cutting in.”

As Mrs. Mew turned to leave, Popper asked her to find one of his books. She disappeared and returned empty-handed. “Excuse me, Karl, I couldn't find it,” she reported. “Unless I have a description, I can't check every bookcase.”

“It was actually, I think, on the right of this corner, but I have taken it away maybe...” His voice trailed off. Mrs. Mew somehow rolled her eyes without really rolling them and vanished.

He paused a moment, and I seized the opportunity to ask a question. “I wanted to ask you about...”

“Yes! You should ask me your questions!  I have wrongly taken the lead. You can ask me all your questions first.”

I noted that in his writings he seemed to abhor the notion of absolute truths. “No no!” Popper replied, shaking his head. He, like the logical positivists before him, believed that a scientific theory can be “absolutely” true. In fact, he had “no doubt” that some current theories are true (although he refused to say which ones). But he rejected the positivist belief that we can ever know that a theory is true. “We must distinguish between truth, which is objective and absolute, and certainty, which is subjective.”

Read more here: Scientific American