Tolerance, Truth, and Mistakes : Popper

karl popper, tolerance, intolerance, intolerance, philosophy, idols of the tribe, s. conde

“Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them.” – Karl Popper, On the Paradox of Tolerance, in The Open Society and Its Enemies, 1945

I would like to copy and paste the entirety of “The Open Society and Its Enemies” here, but I can not.

Please take a moment to read the paper “Toleration and Intellectual Responsibility” by Popper posted below.  We owe it to ourselves during this upcoming political cycle and always.


Toleration and Intellectual Responsibility

Sir Karl Popper[1]


I have been asked here today to repeat a lecture which I gave in Tübingen, on the theme “Toleration and Intellectual Responsibility.” The lecture is dedicated to the memory of Leopold Lucas, a scholar, a historian, a man of toleration and humanity who became a victim of intolerance and inhumanity.

At the age of seventy, in December 1942, Dr. Leopold Lucas and his wife were imprisoned in the Theresienstadt concentration camp, where he worked as a rabbi: an immensely difficult task. He died there ten months later. Dora Lucas, his wife, was kept in Theresienstadt for another thirteen months, but she was able to work as a nurse. In October 1944 she was deported to Poland, together with 18,000 other prisoners. There she was put to death.

It was a terrible fate. It was the fate of countless human beings; people who loved other people, who tried to help other people; who were loved by other people and whom other people tried to help. They belonged to families which were torn apart, destroyed, exterminated.

I do not intend, here, to talk about these dreadful events. Whatever one may try to say – or even to think – it always seems like an attempt to belittle events that defy the imagination.

But the horror continues. The refugees from Vietnam; the victims of Pol Pot in Cambodia; the victims of the revolution in Iran; the refugees from Afghanistan and the Arab refugees from Israel: time and time again, children, women and men become the victims of crazed fanatics.

What can we do to prevent these monstrous events? Can we do anything at all? My answer is: yes. I believe that there is a great deal that we can do. When I say “we,” I mean the intellectuals, that is, human beings who are interested in ideas; especially those who read and, perhaps, write.

Why do I think that we, the intellectuals, are able to help? Simply because we, the intellectuals, have done the most terrible harm for thousands of years. Mass murder in the name of an idea, a doctrine, a theory, a religion – that is all our doing, our invention: the invention of the intellectuals. If only we would stop setting man against man – often with the best intentions – much would be gained. Nobody can say that it is impossible for us to stop doing this.

The most important of the Ten Commandments is: Thou shalt not kill! It contains nearly the whole of ethics. The way in which Schopenhauer, for example, formulates ethics is merely an extension of this most important commandment. Schopenhauer’s ethics are simple, direct and clear. He says: Hurt no one, but help all, as well as you can!

But what happened when Moses came down for the first time with the stone tablets from Mount Sinai, before he could even announce the Ten Commandments? He witnessed a horrible heresy, the heresy of the golden calf. At this he forgot all about the commandment “Thou shalt not kill!” and he shouted (Exodus 32):

Who is on the Lord’s side? Let him come unto me And he said unto them, Thussaith the Lord God of Israel, Put every man his sword by his side, and slay everyman his brother, and every man his companion, and every man his neighbour And there fell of the people that day about three thousand men.

That was, perhaps, the beginning. But what is certain is that things continued to go on in this way; in the Holy Land, and later here in the West. And in the West especially, after Christianity attained the status of an official religion. It became a terrible story of religious persecution, persecution for the sake of orthodoxy. Later – above all in the seventeenth and eighteenth centuries – still other ideologies competed in justifying persecution, cruelty and terror: nationalism, race, political orthodoxy and other religions.

Behind the ideas of orthodoxy and of heresy the pettiest of vices lie hidden; those vices to which the intellectuals are particularly prone: arrogance, smugness verging on dogmatism, intellectual vanity. All these are petty vices – not major vices like cruelty.


The title of my lecture, “Toleration and Intellectual Responsibility,” alludes to an argument of Voltaire, the father of the Enlightenment; an argument in defence of toleration.[2] Voltaire asks, “What is toleration?” and he answers:

Toleration is the necessary consequence of realizing our human fallibility: to err is human, and we do it all the time. So let us pardon each other’s follies. This is the first principle of natural right.

Here Voltaire is appealing to our intellectual honesty: we should admit our mistakes, our fallibility, our ignorance. Voltaire knows full well that utterly convinced fanatics do exist. But is their conviction truly honest? Have they honestly examined themselves, their beliefs and their reasons for holding those beliefs? And is not a self-critical attitude part of all intellectual honesty? Is not fanaticism often an attempt to drown our own unadmitted disbelief that we have suppressed and are therefore only half conscious of?

Voltaire’s appeal to our intellectual modesty and above all his appeal to our intellectual honesty made a great impression on the intellectuals of his time. I should like to restate this appeal here.

The reason given by Voltaire in support of tolerance is that we should pardon each other’s follies. But a common folly, that of intolerance, Voltaire finds, quite rightly, is difficult to tolerate. Indeed, it is here that tolerance has its limits. If we concede to intolerance the right to be tolerated, then we destroy tolerance, and the constitutional state. That was the fate of the Weimar Republic.[3]

But apart from intolerance there are still other follies that we should not tolerate; above all that folly which makes intellectuals follow the latest fashion; a folly which has caused many a writer to adopt an obscure, impressive [and cryptic] style. This style, the style of big and obscure words, of words bombastic and incomprehensible, this manner of writing should no longer be admired, nor even tolerated by intellectuals. It is intellectually irresponsible. It destroys healthy common sense; it destroys reason. It makes possible the philosophy that has been described as relativism; a philosophy that amounts to the thesis that all theses are intellectually more or less equally defensible. Anything goes! So the thesis of relativism leads to anarchy, to unlawfulness; and to the rule of violence.

My theme, toleration and intellectual responsibility, has thus led me to the question of relativism.

At this point I would like to compare relativism with a position which is almost always confused with relativism, yet is in fact entirely different from it. I have often described this position as pluralism; but this has simply led to these misunderstandings. I will therefore characterize it here as critical pluralism. Whilst relativism, arising from a lax form of toleration, leads to the rule of violence, critical pluralism can contribute to the taming of violence.

In order to distinguish relativism from critical pluralism, the idea of truth is of crucial importance. 

Relativism is the position that everything can be asserted, or practically everything, and therefore nothing. Everything is true, or nothing. Truth is therefore a meaningless concept.

Critical pluralism is the position that in the interest of the search for truth, all theories – the more, the better – should be allowed to compete with all other theories. This competition consists in the rational discussion of theories and in their critical elimination. The discussion should be rational – and that means that it should be concerned with the truth of the competing theories: the theory that seems to come closer to the truth in the course of the critical discussion is the better one; and the better theory replaces the inferior theories. It is therefore the question of truth which is at stake.


The idea of objective truth and the idea of the search for truth are of decisive importance here.

The first thinker to develop a theory of truth, and to link the idea of objective truth with the idea of our basic human fallibility, was the Pre-socratic Xenophanes.[4] Born in 57! BCE in Ionia, Asia Minor, he was the first Greek to write literary criticism; the first moral philosopher; the first to develop a critical theory of human knowledge; and the first speculative monotheist.

Xenophanes was the founder of a tradition, of a way of thinking, to which have belonged, among others, Socrates, Erasmus, Montaigne, Locke, Hume, Voltaire and Lessing. This tradition is sometimes called the sceptical school. Such a description, however, can easily lead to misunderstandings. The Concise Oxford Dictionary, for example, says: “Sceptic. ..person who doubts truth of … religious doctrines, agnostic, … atheist; … or who takes cynical views.” But the Greek word from which the word is derived means (as the Oxford Dictionary tells us) “to look out,” “to inquire,” “to reflect,” “to search.”

The sceptics Xenophanes, Socrates, Erasmus, Montaigne, Locke, Voltaire and Lessing were all theists or deists. What all the members of this sceptical tradition have in common …and what I also share with this tradition is that we stress our human ignorance. From this we can point to important ethical consequences: toleration, but not toleration of intolerance, of violence or cruelty.

Xenophanes stated, clearly and honestly, that his theory was no more than conjecture. This was a victory of self-criticism without equal, a victory of his intellectual honesty and of his modesty.

Xenophanes generalized this self-criticism in a manner which, I think, was characteristic of him: it was clear to him that what he had discovered about his own theory – that it was nothing more than conjecture in spite of its intuitive power of persuasion – must be true of all human theories: everything is only conjecture. This seems to me to reveal that it had not been easy for him to view his own theory as conjecture.

Xenophanes formulated his critical theory of knowledge – everything is conjecture – in six beautiful lines of verse:

But as for certain truth, no man has known it,

Nor will he know it; neither of the gods,

Nor yet of all the things of which I speak.

And even if by chance he were to utter

The perfect truth, he would himself not know it:

For all is but a woven web of guesses.

These six lines contain more than a theory of the uncertainty of human knowledge. They contain a theory of objective knowledge. For Xenophanes tells us here that, whilst something I say may be true, neither I nor anybody else will know that it is true. This means, however, that truth is objective: truth is the correspondence of what I say with the facts; whether or not I actually know that the correspondence exists.

In addition, these six lines contain another very important theory. They contain a clue to the difference between objective truth and the subjective certainty of knowledge. For the six lines affirm that, even when I proclaim the most perfect truth, I cannot know this with certainty. For there is no infallible criterion of truth: we can never, or almost never, be quite sure that we have not been mistaken.

But Xenophanes was not an epistemological pessimist. He was a searcher; and during the course of his long life he was able, by way of critical reexamination, to improve many of his conjectures, and more especially his scientific theories. These are his words:

The gods did not reveal, from the beginning,

All things to us; but in the course of time,

Through seeking, we may learn, and know things better.

Xenophanes also explains what he means by “to know things better”: he means the approximation to objective truth: closeness to truth, similarity to truth. For he says of one of his conjectures:

These things, we may well conjecture, resemble the truth ….

In Xenophanes’ theory of truth and of human knowledge we may find the following points:

  1. Our knowledge consists of statements.
  2. Statements are either true or false.
  3. Truth is objective. It is the correspondence of the content of a statement with the facts.
  4. Even when we express the most perfect truth, we cannot know this – that is, we cannot know it with certainty.
  5. Since “knowledge” in the usual sense of the word is “certain knowledge,” there can be no knowledge. There can only be conjectural knowledge: “For all is but a woven web of guesses.”
  6. But in our conjectural knowledge there can be progress to something better.
  7. Better knowledge is a better approximation to the truth.
  8. But it always remains conjectural knowledge – a web of guesses.

For an understanding of Xenophanes’ theory of truth it is important to stress that Xenophanes differentiates clearly between objective truth and subjective certainty. Objective truth is the correspondence of a statement with the facts, whether we know this – know it for certain – or not. Thus, truth must not be confused with certainty or with certain knowledge. He who knows something for certain is he who knows the truth. But it often happens that someone conjectures something without knowing it for certain; and that his conjecture is actually true since it corresponds to the facts. Xenophanes implies quite correctly that there are many truths – and important truths – which nobody knows for certain; and that there are many truths which nobody can know, even though they may be conjectured by some. And he further implies that there are truths which nobody can even conjecture.

Indeed, in any of the languages in which we are able to speak of the infinite sequence of natural numbers, there exists an infinite variety of clear and unambiguous statements (for instance: 172 = 627 + 2). Each of these statements is either true or, if it is false, its negation is true. There are, therefore, infinitely many different true propositions. And from this it follows that there exist infin-itely many true propositions which we shall never be able to know – there are infinitely many unknowable truths.

Even today there are many philosophers who think that truth can be of significance for us only if we possess it; that is, know it with certainty. Yet the knowledge of the existence of conjectural knowledge is of great importance. There are truths which we can only approach by laborious searching. Our path, nearly always, winds its way through error. And without truth there can be no error (and without error there is no fallibility).


Some of the views which I have just described were more or less clear to me, even before I read Xenophanes’ fragments; perhaps I would not have understood them otherwise. It had become clear to me through Einstein that our best knowledge was conjectural, that it was a woven web of guesses. For he pointed out that Newton’s theory of gravity – just like Einstein’s own gravitational theory – is conjectural knowledge, despite its immense success; and, just like Newton’s theory, Einstein’s own theory appears to be only an approximation to the truth. I do not believe that the significance of conjectural knowledge would ever have become clear to me without the work of Newton and Einstein; and so I asked myself how it could have become clear to Xenophanes 2,500 years ago. Perhaps the answer to this question is this: Xenophanes first accepted Homer’s picture of the universe, just as I accepted Newton’s picture of the universe. His first belief was shattered for him just as it was for me: for him through his own criticism of Homer, for me by Einstein’s criticism of Newton. Xenophanes, just like Einstein, replaced the criticized picture of the universe with another; and both were aware that their new picture of the universe was merely conjecture.

The realization that Xenophanes had anticipated my theory of conjectural knowledge by 2,500 years taught me to be modest. But the idea of intellectual modesty was likewise anticipated for nearly as long. It comes from Socrates.[5]

Socrates was the second, and much more influential, founder of the sceptical tradition. He taught: only he is wise who knows that he is not.

Socrates and, at about the same time, Democritus made the same ethical discovery quite independently of each other. Both said, in very similar words: “It is better to suffer injustice than to commit an injustice.”

One can claim that this insight – at least if combined with the knowledge of how little we know -leads, as Voltaire taught much later, to toleration.


I shall now turn to the contemporary significance of this self-critical philosophy of knowledge.

First, we must discuss the following important objection. It is true, somebody may say, that Xenophanes, Democritus and Socrates did not know anything; and it was indeed wise that they recognized their own lack of knowledge; and perhaps even wiser that they adopted the attitude of seeking or searching for knowledge. We – or more precisely our scientists – are still searchers, researchers. But today scientists are not only seeking but also finding. And they have found a great deal; so much indeed that the very volume of our scientific knowledge has become a problem. Is it right, therefore, that we should continue even now in all sincerity to build up our philosophy of knowledge upon the Socratic thesis of lack of knowledge?

The objection is correct, but only in the light of four very important additional points.

First, when it is suggested that science knows a great deal, this is correct, but the word “knowledge” is used here, apparently unconsciously, in a sense which is completely different from that intended by Xenophanes and Socrates, and also from the meaning given to the word “knowledge” in current everyday usage. For by “knowledge” we usually mean “certain knowledge.” If someone says, “I know that today is Tuesday but I am not sure that today is Tuesday,” he is contradicting himself, or retracting in the second half of his statement what he is saying in the first half.

But our scientific knowledge is still not certain knowledge. It is open to revision. It consists of testable conjectures, of hypotheses – at best, of conjectures that have been subjected to the most stringent tests, yet, still, of conjectures only. This is the first point, and it is in itself a complete justification of Socrates’ emphasis on our lack of knowledge, and of Xenophanes’ comment that, even when we speak the perfect truth, we could not know that what we have said is true.

The second point, which must be added to the objection that we know so much nowadays, is this: with almost every new scientific achievement, with every hypothetical solution of a scientific problem, both the number of the unsolved problems and the degree of their difficulty increase. In fact, they increase much faster than the solutions. One might well say that whilst our hypothetical knowledge is finite, our ignorance is infinite. But not only that, for the genuine scientist with a feeling for unsolved problems, the world is becoming, in a very concrete sense, more and more of a riddle.

My third point is this: when we say that today we know more than Xenophanes or Socrates did, it is probably incorrect if we take “know” in a subjective sense. Presumably none of us know more; we simply know different things. We have replaced particular theories, particular hypotheses, particular conjectures by others; admittedly, in most cases by better ones: better in the sense of being a better approximation to the truth.

The content of these theories, hypotheses, conjectures may be called knowledge in the objective sense, as opposed to subjective or personal knowledge. For example, the content of an encyclopaedia of physics is impersonal or objective – and of course hypothetical- knowledge: it far exceeds what the most learned physicist can possibly know. What a physicist knows – or, more exactly, conjectures – may be called his personal or subjective knowledge. Both – the impersonal and personal knowledge – are mainly hypothetical and capable of improvement. Yet not only does the impersonal or objective knowledge currently go far beyond the personal knowledge of any human being, it also advances so rapidly that personal or subjective knowledge can only keep up with it in small areas and for short periods of time and is, in the main, constantly becoming outdated.

This is the fourth reason why Socrates is still right. For this outdated knowledge consists of theories which have been found to be false: outdated knowledge is not knowledge, at least not in the ordinary sense of the word.


So we have four reasons that show even today that the Socratic insight, “I know that I know almost nothing, and hardly this,” is still highly relevant – possibly even more so than in Socrates time. And we have good reason, in the defence of toleration, to derive from this insight those ethical consequences which Erasmus, Montaigne, Voltaire and later Lessing derived from it. But there are still other consequences.

The principles that form the basis of every rational discussion, that is, of every discussion undertaken in the search for truth, are in the main ethical principles. I should like to state three such principles.

  1. The principle of fallibility: perhaps I am wrong and perhaps you are. But we could easily both be wrong.
  1. The principle of rational discussion: we want to try, as impersonally as possible, to weigh up our reasons for and against a theory: a theory that is definite and criticizable.
  1. The principle of approximation to the truth: we can nearly always come closer to the truth in a discussion which avoids personal attacks. It can help us to achieve a better understanding; even in those cases where we do not reach an agreement.

It is worth noting that these three principles are both epistemological[6] and ethical principles. For they imply, among other things, toleration: if I hope to learn from you, and if I want to learn in the interest of truth, then I have not only to tolerate you but also to recognize you as a potential equal; the potential unity and equality of all men somehow constitute a prerequisite of our willingness to discuss matters rationally. Of importance also is the principle that we can learn much from a discussion, even when it does not lead to agreement: a discussion can help us by shedding light upon some of our errors.

Thus ethical principles form the basis of science. The idea of truth as the fundamental regulative principle – the principle that guides our search – can be regarded as an ethical principle.

The search for truth and the idea of approximation to the truth are also ethical principles; as are the ideas of intellectual integrity and of fallibility, which lead us to a self-critical attitude and to toleration.

It is also very important that we can learn in the field of ethics.


I should like to demonstrate this by looking at the example of an ethics for the intellectuals, especially for the intellectual professions: an ethics for scientists, for doctors, lawyers, engineers, and for architects; for civil servants and, most importantly, for politicians.

I should like to put before you some principles for a new professional ethics, principles closely connected with the concepts of toleration and intellectual honesty.

For this purpose I will first characterize the old professional ethics, perhaps even drawing a bit of a caricature, in order to compare it with the new professional ethics I am proposing.

Both the old and the new professional ethics are based, admittedly, upon the concepts of truth, of rationality and of intellectual responsibility. But the old ethics was based upon the idea of personal knowledge and of certain knowledge and, therefore, upon the idea of authority; whereas the new ethics is based upon the idea of objective knowledge and of uncertain knowledge. This signifies a fundamental change in the underlying way of thinking and, consequently, in the way that the ideas of truth, of rationality and of intellectual honesty and responsibility function.

The old ideal was to possess truth – certain truth – and, if possible, to guarantee truth by means of a logical proof.

This ideal, widely accepted to this day, is the idea of wisdom in person, the sage; not of “wisdom” in the Socratic sense, of course, but in the Platonic sense: the sage who is an authority; the learned philosopher who claims power: the philosopher king.

The old imperative for the intellectuals is: Be an authority! Know everything in your field!

Once you are recognized as an authority, your authority will be protected by your colleagues; and you must of course protect the authority of your colleagues.

The old ethics I am describing leaves no room for mistakes. Mistakes are simply not allowed. Consequently, mistakes must not be acknowledged. I do not need to stress that this old professional ethics is intolerant. Moreover, it always has been intellectually dishonest: it leads (especially in medicine and in politics) to the covering up of mistakes for the sake of protecting authority.

This is why I suggest that we need a new professional ethics, mainly, but not exclusively, for scientists. I suggest that it be based upon the following twelve principles, with which I shall conclude this lecture. Our objective conjectural knowledge goes further and further beyond what anyone person can So there simply cannot be any “authorities.” This holds true also within specialized subjects.

  1. Our objective conjectural knowledge goes further and further beyond what anyone person can master. So there simply cannot be any “authorities.” This holds true also within specialized subject.
  2. It is impossible to avoid all mistakes, or even all those mistakes that are, in themselves, All scientists are continually making mistakes. The old idea that one can avoid mistakes and is therefore duty bound to avoid them, must be revised: it is itself mistaken.
  3. Of course it remains our duty to avoid mistakes whenever possible. But it is precisely so that we can avoid them, that we must be aware, above all, of how difficult it is to avoid them and that nobody succeeds completely. Not even the most creative scientists who are guided by intuition succeed: intuition may mislead us.
  4. Mistakes may be hidden even in those theories which are very well corroborated; and it is the specific task of the scientist to search for such mistakes. The observation that a well-corroborated theory or a technique that has been used successfully is mistaken may be an important discovery.
  5. We must therefore revise our attitude to mistakes. It is here that our practical ethical reform must begin. For the attitude of the old professional ethics leads us to cover up our mistakes, to keep them secret and to forget them as soon as possible
  6. The new basic principle is that in order to learn to avoid making mistakes we must learn from our mistakes. To cover up mistakes is, therefore, the greatest intellectual sin.
  7. We must be constantly on the look-out for mistakes. When we find them we must be sure to remember them; we must analyse them thoroughly to get to the bottom of things.
  8. The maintenance of a self-critical attitude and of personal integrity thus becomes a matter of duty.
  9. Since we must learn from our mistakes, we must also learn to accept, indeed accept gratefully, when others draw our attention to our mistakes. When in turn we draw other people’s attention to their mistakes, we should always remember that we have made similar mistakes ourselves. And we should remember that the greatest scientists have made mistakes. I certainly do not want to say that our mistakes are, usually, forgivable: we must never let our attention slacken. But it is humanly impossible to avoid making mistakes time and again.
  10. We must be clear in our own minds that we need other people to discover and correct our mistakes (as they need us); especially those people who have grown up with different ideas in a different environment. This too leads to toleration.
  11. We must learn that self-criticism is the best criticism; but that criticism by others is a necessity. It is nearly as good as self-criticism.
  12. Rational criticism must always be specific: it must give specific reasons why specific statements, specific hypotheses, appear to be false, or specific arguments invalid. It must be guided by the idea of getting nearer to objective truth. In this sense it must be impersonal.

I ask you to regard these points as suggestions. They are meant to demonstrate that, in the field of ethics, too, one can put forward suggestions which are open to discussion and improvement.

Bibliographic Citation:

Popper, Karl. “Toleration and Intellectual Responsibility.” In Search of a Better World: Lectures and Essays from Thirty Years. Trans. Laura J. Bennett. London: Routledge, 1996. 188-203.

[1]Sir Karl Raimund Popper (I902-I994), was one of the most influential twentieth century philosophers of science. He was noted, as well, for his work in social and political philosophy, which focused on a strong defense of liberal democracy. He was an out·spoken opponent of authoritarianism, dogmatism, intolerance. One of his most important works in this regard was The Open Society and Its Enemies, first published in I945. This book was guided by two principles: “Minimize avoidable suffering” and “Maximize the freedom of individuals to live as they wish.” Popper’s views on science, philosophy, and the nature of truth and knowledge are by no means accepted by all contemporary thinkers. Indeed, this essay merely presents his point of view, which he would expect to be challenged in the most rigorous ways by those with other points of view.

This is an abridged version of a lecture delivered at the University of Turbingen on May 26. I98I and repeated in Vienna in Spring I98i. This lecture is taken from Karl Popper, In Search of a Better World (Routledge: London and New York. I984), pp. 118-203.

[2] Voltaire, was the nom de plume of Fran”ois Marie Arouet (1694-1778). Voltaire is considered one of the greatest of French philosophers of the Enlightenment, known for his celebration of free·thinking and social reform based on the principles of reason.

[3] The Weimar Republic was the turbulent period of German history between I9I9 and 1933, the first attempt to establish a liberal democracy. It ended with the rise of Adolf Hitler to power. an event which deeply influenced Popper’s thinking and is reflected in this lecture. Popper, like many German and Austrian intellectuals of Jewish origin, was forced to flee Germany and he spent most of his career in England.

[4] The Presocratic philosophers were the first Western philosophers, active in Greece in the sixth and fifth centuries BCE. They were concerned with understanding cosmogony, the world’s origins and order. (From the Concise Routledge Encylopedia of Philosophy.)

[5] Socrates (469-399 B.C.E). was the most influential of all Greek philosophers, whose thought became the standard reference point for all subsequent Western philosophy. Democritus (460-370 B.C.E) is considered to be one of the originators of the idea that all matter consists of atoms and that the ultimate goal of life is to live peacefully and rationally, unperturbed by fear and superstition. Popper’s view of humility in the search for knowledge is very much indebted to these thinkers, although in other works, he was extremely critical, especially of Plato’s Republic, which he felt was a blueprint for a totalitarian or “closed” society.

[6] By epistemological. Popper means that these guidelines are useful in our search for knowledge, in addition to how we interact with one another in that search for knowledge. In philosophy, epistemology is the study of the nature, extent, sources, and the legitimacy of knowledge.


This paper was copied from PhilPapers : Philosophical Research Online.