The Stanford Encyclopedia of Philosophy writes that Popper "is generally regarded as one of the greatest philosophers of science of the 20th century." It is Sir Karl Popper: he was knighted by Queen Elizabeth II in 1965.
Fundamental to Popper's point of view is his belief in what he called the Open Society. Science, he believed, worked best where people were free. Authoritarian governments were inclined toward myth. He believed that ideologues in power, as in Hitler's Germany or Stalinist Russia, had an interest in maintaining myth, and he saw science as always involved in refuting myth. During World War II he wrote his well-known two volumes The Open Society and Its Enemies, critical of Plato, Hegel, and Marx.
About knowledge and science, Popper began with our limitations: "Our knowledge can only be finite, while our ignorance must necessarily be infinite."
There was a pragmatic element to Popper's philosophy. Life is continuing problem solving. The growth of human knowledge proceeds from our problems and our attempts at solving them. He had respect for the everyday need for a common understanding of the meaning of words, but he had little respect for philosophy's "linguistic puzzles." For example, he derided the philosophical quibble over the difference between "being" and "existing." This put him at odds with Ludwig Wittgenstein, who has been described (unfairly) as seeing language as the key to dissolving all philosophical problems. At a meeting attended by the two on a cold winter day, Wittgenstein threatened Popper with a fireplace poker and then stormed out of the room. (See Wikipedia's Wittgenstein's Poker.)
Popper limited scientific knowledge to that which was available to challenge. We can challenge claims as to global warming and various conclusions drawn from laboratory research and experimentation, but we cannot disprove that God is great. In other words, Popper did not leave simple empiricism or the inductive method as a criterion for science. Astrology was to an extent empirical, and most students of philosophy know about the induction fallacy. The induction method looks for confirmation while Popper's method does the opposite: it attempts refutation.
Popper critics among scientists hold that Popper's idea of what is science is too limited. He was falsely accused of missing out on the larger scientific theories. And it was pointed out that some successful theories were at the start refuted. The Copernican Revolution, for example, required several different developments over the course of over a century. But Popper realized that theories, scientific and otherwise, embody a body of factual connections and that a theory once refuted can be rehabilitated by replacing that part which is false with a fact that is refutable, keeping alive the larger theory, scientifically if the theory is built with refutable parts. Popper's criterion for science, plus his view of the world as an interconnection of forces, mixed with the infinity of our ignorance, is compatible with what has been described by others as working toward truth through approximation – which stands apart from those who believe that they have a grasp of theory completely devoid of ignorance, to a point that they do not recognize their theory as theory.
Applied to history, Popper claimed that we do not know exactly what the future holds because we do not know the choices that people are going to make. He argued against the idea that history was on an inevitable course, as held by Hegel and Marx. He saw a difference between conditional predictions: if A happens then B will happen, as opposed to the claim that B is going to happen regardless.
Time will tell, it has been said. Time has exposed Hegel's idea about the future as false. Marx's view of the future differed from Hegel's. He saw the future in terms of broad sociological forces which we might say still exist, or we can be generous and say that the world Marx knew has changed and that Marxism is today as irrelevant as it seems to be in China – something Marx didn't foresee.
Copyright © 2016 by Frank E. Smitha. All rights reserved.