There’s a straightforward path to philosophy. That is, we each have prejudices — racial prejudices, class prejudices, religious prejudices, sexual prejudices, academic prejudices, the list goes on. And the important thing about philosophy is that it criticize these prejudices. It shows, through criticism, how dependent and false these prejudices are, and then attempts to improve or eliminate those which we find objectionable.

Philosophy of Science

This philosophical path is even true of science, of scientific prejudices or theories. Scientific laws can never be proved, neither by experiements, nor by logical deduction. All scientific theories are conjectures, ingeniously conceived hypotheses, which can never be translated into truths.

One must proceed differently, indirectly. One must try to show the falsity of a theory — try to falsify it, as Popper says. If an error is found, then the scientific conjecture is untrue, and a new draft that avoids this possible error will come a bit closer to truth. This was the underlying theme of Popper’s revolutionary book, the Logic of Scientific Discovery, which was published in 1934.

One good and interesting example to demonstrate Popper’s point is Einstein’s theory of gravitation. One consequence of Einstein’s theory — one deduction — is that light coming from a distance star to the earth will be deflected near the sun. Einstein calculated that under certain conditions, even in Newtonian theory, such a deviation would result, but far less than his own theory.

Now, you normally can’t see a star when it is close to the sun. But Einstein realized that during a solar eclipse, when the moon is in front of the sun, one could photograph the stars around the sun and compare it with a photograph taken of the same group of stars without the sun. One just needs to take a picture of the same group of stars six months later when the sun isn’t in the location of the stars.

This was done by Eddington in 1919. The cluster of stars where the sun was expected were photographed six months before the solar eclipse. And then during the solar eclipse the same cluster of stars were recorded when they were near the sun. And it turned out that the stars were exactly where they had been predicted.

Popper’s explanation of the scientific character of Einstein’s theory provoked the question whether Eddington’s observations had proved the theory. ‘Of course not,’ Popper argued. One cannot prove scientific theories at all. A scientific theory is rich with many consequences, much can be derived from it. Einstein, for example, had no idea at the time he had created his theory of general relativity that one of its consequences leads to regions in space where gravity is too strong for anything to escape — black holes.

In any case, a proof that one consequence (or any number of consequences) is correct cannot prove that all the other consequences are correct — there are infinitely many. The theory can, however, become more interesting, it can succeed or stand the test. But it cannot be proved. If, on the other hand, Eddington’s observation had turned out the other way, if it hadn’t led to the deviations predicted by Einstein’s theory, the theory would’ve been refuted.

Another important point, which Popper has tried endlessly to keep in the minds of philosophers and scientists, and as Einstein’s theory demonstrates, theories always come before observations. Only after you have a theory, can you then know where to look and what to look for. The important thing here to understand, especially for scientists, then, is that experiments, though they may seem to prove a theory, in reality, can only refute them. There is no way to confirm a theory as absolutely true, since all science is hypothetical.

This is an idea that completely distinguishes Popper from the so-called positivists, who seek to build science only on empirically justifiable and certain grounds, whereas Popper claims that science, because it is conjectural, cannot rest on solid ground. Science, as with the growth of all knowledge, proceeds speculatively, and observation and experimentation are used only to refute theories, not to prove them as demonstrably true. We can only learn from mistakes.

“While differing widely in the various bits we know, in our infinite ignorance we are all equal.” — Popper

Philosophy of Society

Societal experience is a strong motivating factor in Popper’s thought. He has written in detail, as a second major theme of his philosophy, about the problems of society. Popper examined extensively Western history and the underlying ideas operating throughout its cultures. And he discovered that, at the start of dictatorial movements, there were often men who claimed to have found the true laws of history, which allowed them to deduce the ultimate or ideal state — heaven on earth.

One of the main offenders, Popper argues, is Plato, who designed an ideal authoritarian state where philosopher kings rule. Popper also identified Hegel and Marx, as well as their successors, as soothsayers who ignited totalitarian regimes, after claiming to have found in the history books the laws of society. (See The Open Society and its Enemies.)

False prophets, as Popper calls them, tend to act with the best of intentions. But they want to impose salvation on all by force, bringing a new murderous misery to mankind, justifying it with the promise of the final goal of paradise on earth. Closed societies emerge, then, when dissenters and critics are brutally persecuted in the name of some ideal — the perfect state.

What is meant by an Open Society, on the other hand, is a society in which one can breathe freely, think freely, one in which every human has a value, and in which society doesn’t exert a superfluous constraint on people.

There are societies that are more or less open, and there are societies that are not open at all. Our Western democracies were largely open societies even during the War. But since then, unfortunately, more and more politics has become so intricate, and party discipline has become so tight, that party leaders, and those lobbyists which fund them, have almost dictatorial powers.

This is some bad shit. And it’s the fault of no one but ourselves that our constitutions give parliaments this power. Individuals create constitutions. And only individuals can change them. And we should, since this near omnipotence of parliaments has the effect of making the ruling party practically all-powerful, which, as already suggested, makes the governing party leader practically all-powerful.

The basic idea of all democracy is to limit power, to control it. Power has to be distributed so that there’s not too much in a single hand or group. This can and should be done by relatively simple things, through relatively simple constitutional changes.

Democracy is a great experiment. And the various forms of democracy have to be tested against each other. No one is capable of foreseeing all the difficulties of possible internal contradictions which are actualized in legislation, put into effect through legislation. There is always something awry in a way that one can’t anticipate. But that is precicesely the reason why in politics one should adopt a more experimental attitude.

“The problem in political philosophy should not be ‘Who should rule?’, but rather ‘How can we organize political institutions so that bad or incompetent rulers can be prevented from doing too much damage?”

Clear Thinking, Writing, & Communicating

This experimental attitude also has the striking feature of being very easily and clearly formulated. In Popper’s opinion, it’s a life task to train to speak as clearly as possible. This isn’t achieved by paying special attention to words, but by formulating ideas clearly, clearly enough so as to be criticizable or testable. People who speak too much about words or concepts or definitions don’t actually bring anything to the table. So, you can’t do anything with or against their definitions, since they are void of content.

A definition is a purely conventional matter. There is an attitude here, which is utterly ruinous for philosophy. Namely, the attitude that expects everyone to be able to define the terms they use. If, for example, someone says to define human, and one gives the answer: ‘Human, that’s a featherless biped’ or ‘a biped without feathers,’ or the other Aristotelian definition: ‘A human is a rational animal.’ Do we then know more about humans? If we didn’t first know something about humans, we won’t know after the definition either.

Definitions don’t really help. They only lead to a pretentious, false precision, the impression that one is particularly precise. But it’s a sham precision, it’s not genuine clarity. For that reason, Popper is against the discussion of terms and definitions. He prefers simple and clear speaking. But unfortunately his request has been largely ignored, especially in philosophy and politics.

In the Open Society, Popper showed particularly that political philosophy and political discussion is full of definitions and discussions of terms. He therefore argued that one should replace this approach with a discussion of political proposals — proposals of what one should actually accomplish. This doesn’t depend on the definition of words. We can use yours or mine, as long as we understand the proposal. Instead of political philosophy repeatedly discussing ‘what is sovereignty?’ or ‘what is the state?’ and similar questions that don’t lead anywhere at all, one should instead discuss things like: ‘To what extent should the state interfere in the private affairs of citizens? And when?’ That is a real problem, not ‘what is the state?’.

Many have claimed that Popper’s thinking leads to relativism, since a final recognition of absolute truth is ruled out by Popper in all areas. But in his philosophy there is talk of verisimilitude — or a continuous approximation to the truth. This means that there is absolute truth, although we never know if we’ve reached it. In other words, there is an objective reality, indeed of which we are a part. And every philosophy stands or falls with its position on the issue of truth.

Objective Knowledge & Truth

The concept of objective truth has unfortunately become unfashionable. It has become unfashionable because the people who believed in absolute truth also believed that they had the absolute truth in their pocket. They put forward all sorts of theories that they claimed as absolutely true. That is why the absolute concept of truth has precisely been rejected by more modest thinking. But that was an error.

The right attitude is to say there is an absolute truth, but unfortunately, even when we try to express truth, we often don’t know whether it’s really true. A scientific theory may be very much like truth, but we cannot prove it. We can only say it has succeeded, thus far, to stand up to our severests criticisms. But we never can hold the truth in our pocket. For this reason, the concept of an absolute objective truth is to be used cautiously, only as an ideal or as what Kant called a ‘regulative idea’.

A regulative idea guides us, it regulates our thinking, but it isn’t an idea that we can achieve. We must approach the question of truth by critical discussion. Only through critical discussion, by chipping away at our mistakes, can we get closer to the question of whether a claim is true or false. But we mustn’t confuse our claims with absolute truth. They will always be conjectures — sometimes very good conjectures, very well-corroborated and well-tested conjectures, like some of our best scientific theories, but conjectures nonetheless.

This discussion of truth is very important. For it’s only when we establish a concept of absolute truth that we can really see how modest or humble we must be, because we simply don’t have any criterion of truth. This is called ‘fallibilism’, which means the fallibility not only of every person, but of the process of science, which is a very important position. Fallibilism requires a notion of absolute truth — an objective reality — by which we can measure our errors of judgment, our weaknesses.

Moral Philosophy

This naturally leads to the question: Are there any connections between truth and the issue of ethics? Yes, Popper argues, many connections. Most ethical criticisms of society begin by repeatedly criticizing the hypocrisy or mendacity of society, which is a direct attack on our societal relations with the concept of truth. This attack clearly implies that truth is considered an ethical value to begin with.

Even science, which many people claim to be void of ethics or values, is very much dependent on ethical principles — principles that are manifested in its search for truth. This ethical principles is indirectly anchored in science. It’s not a consequences of science, but a pre-condition of it.

Samuel Johnson, to refute Bishop Berkeley’s immaterialism, kicked a rock and said, ‘I refute him thus!’

Popper’s philosophy has been a strong orienting force, though he never makes unfulfillable promises. Popper has defended reason, which is often threatened today, without building a restrictive system in its name. False prophets from all camps fear the critical potency of his philosophy. It is an effective remedy against all intellectual seduction. Its restraint avoids criticism of resignation and sullenness.


Let me close with what Popper referred to as our duty: our duty to remain optimists. We are products of nature, but nature has made us together with our power of altering the world, of forcing and of planning for the future, and of making far-reaching decisions for which we are morally responsible. Thus, the future is open. And it depends on us, on our beliefs, on our actions. It is up to you, then, to build a better tomorrow.

By John Driggs

Karl Popper’s Bibliography: