Category: .Popper, Karl

The subjectivist blunder of common-sense knowledge

The phenomenon of human knowledge is no doubt the greatest miracle in our universe. It constitutes a problem that will not soon be solved, and I am far from thinking that the preset volume makes even a small contribution to its solution. But I hope that I have helped to restart a discussion which for three centuries has been bogged down in preliminaries.

Since Descartes, Hobbes, Locke, and their school, which includes not only David Hume but also Thomas Reid, the theory of human knowledge has been largely subjectivist: knowledge has been regarded as a specially secure kind of human belief, and scientific knowledge as a specially secure kind of human knowledge.

The essays in this book break with a tradition that can be traced back to Aristotle—the tradition of this commonsense theory of knowledge. I am a great admirer of common sense which, I assert, is essentially selfcritical. But while I am prepared to uphold to the last the essential truth of commonsense realism, I regard the commonsense theory of knowledge as a subjectivist blunder. This blunder has dominated Western philosophy. I have made an attempt to eradicate it, and to replace it by an objective theory of essentially conjectural knowledge. This may be a bold claim but I do not apologize for it. [Preface]

Nothing can be proved

The critical attitude, the tradition of free discussion of theories with the aim of discovering their weak spots so that they may be improved upon, is the attitude of reasonableness, of rationality. It makes far-reaching use of both verbal argu­ment and observation—of observation in the interest of argument, however. The Greeks’ discovery of the critical method gave rise at first to the mistaken hope that it would lead to the solution of all the great old problems; that it would establish certainty; that it would help to prove our theories, to justify them. But this hope was a residue of the dogmatic way of thinking; in fact nothing can be justified or proved (outside of mathematics and logic). The demand for rational proofs in science indicates a failure to keep distinct the broad realm of rationality and the narrow realm of rational certainty: it is an untenable, an unreasonable demand. [67]

Absolutely authoritarianism-free absolutism

The idea of a philosophical absolutism is rightly repugnant to many people since it is, as a rule, combined with a dog­matic and authoritarian claim to possess the truth, or a criterion of truth.

But there is another form of absolutism—a fallibilistic absolutism—which indeed rejects all this: it merely asserts that our mistakes, at least, are absolute mistakes, in the sense that if a theory deviates from the truth, it is simply false, even if the mistake made was less glaring than that in another theory. Thus the notions of truth, and of falling short of the truth, can represent absolute standards for the fallibilist. This kind of absolutism is completely free from any taint of authori­tarianism. [Addenda, 567-8]

One truth for the Greeks

Herodotus seems to have been one of those somewhat rare people whose minds are broadened by travel. At first he was no doubt shocked by the many strange customs and institutions which he encountered in the Middle East. But he learned to respect them, and to look on some of them critically, and to regard others as the results of historical accidents: he learned to be tolerant, and he even acquired the ability to see the customs and institutions of his own country through the eyes of his barbarian hosts.

This is a healthy attitude. But it may lead to relativism, that is, to the view that there is no absolute or objective truth, but rather one truth for the Greeks, another for the Egyptians, still another for the Syrians, and so on. [45]

Truth is above human authority

If only we look for it we can often find a true idea, worthy of being preserved, in a philosophical theory which must be rejected as false. Can we find an idea like this in one of the theories of the ultimate sources of our knowledge?

I believe we can; and I suggest that it is one of the two main ideas which underlie the doctrine that the source of all our knowledge is super-natural. The first of these ideas is false, I believe, while the second is true.

The first, the false idea, is that we must justify our knowledge, or our theories, by positive reasons, that is, by reasons capable of establishing them, or at least of making them highly probable; at any rate, by better reasons than that they have so far withstood criticism. This idea implies, I suggested, that we must appeal to some ultimate or authoritative source of true knowledge; which still leaves open the character of that authority–whether it is human, like observation or reason, or super-human (and therefore supernatural).

The second idea—whose vital importance has been stressed by Russell—is that no man’s authority can establish truth by decree; that we should submit to truth; that truth is above human authority.

Taken together these two ideas almost immediately yield the conclusion that the sources from which our knowledge derives must be super-human; a conclusion which tends to encourage self-righteousness and the use of force against those who refuse to see the divine truth.

Some who rightly reject this conclusion do not, unhappily, reject the first idea—the belief in the existence of ultimate sources of knowledge. Instead they reject the second idea—the thesis that truth is above human authority. They thereby endanger the idea of the objectivity of knowledge, and of common standards of criticism or rationality. [38-9]

Freedom: Liberalism vs Libertarianism

Although the political theory which I call protectionism is not connected with any of these tendencies, and although it is fundamentally a liberal theory, I think that the name may be used to indicate that, though liberal, it has nothing to do with the policy of strict non-intervention (often, but not quite correctly, called ‘laissez faire’). Liberalism and state-interference are not opposed to each other. On the contrary, any kind of freedom is clearly impossible unless it is guaranteed by the state. [ch. 6, 121]

The paradox of freedom

Now this argument which tries to show that ‘liberty’ is the same as ‘a liberty’ and therefore the same as ‘law’, from which it follows that the more laws, the more liberty, is clearly nothing but a clumsy statement (clumsy because it relies on a kind of pun) of the paradox of freedom, first discovered by Plato …; a paradox that can be expressed by saying that unlimited freedom leads to its opposite, since without its protection and restriction by law, freedom must lead to a tyranny of the strong over the weak. This paradox, vaguely restated by Rousseau, was solved by Kant, who demanded that the freedom of each man should be restricted, but not beyond what is necessary to safeguard an equal degree of freedom for all. [ch. 12, 296]

Decisions cannot be derived from facts

It is important for the understanding of this attitude to realize that these decisions can never be derived from facts (or from statements of facts), although they pertain to facts. The decision, for instance, to oppose slavery does not depend upon the fact that all men are born free and equal, and that no man is born in chains. For even if all were born free, some men might perhaps try to put others in chains, and they may even believe that they ought to put them in chains. And conversely, even if men were born in chains, many of us might demand the removal of these chains. Or to put this matter more precisely, if we consider a fact as alterable—such as the fact that many people are suffering from dis­eases—then we can always adopt a number of different attitudes towards this fact: more especially, we can decide to make an attempt to alter it; or we can decide to resist any such attempt; or we can decide not to take action at all.

All moral decisions pertain in this way to some fact or other, especially to some fact of social life, and all (alterable) facts of social life can give rise to many different decisions. Which shows that the decisions can never be derivable from these facts, or from a description of these facts. [ch. 5, 67]

The relativity of proof

Every proof must proceed from premises; the proof as such, that is to say, the derivation from the premises, can there­fore never finally settle the truth of any conclusion, but only show that the conclusion must be true provided the prem­ises are true. [ch. 11, 260]

To remain human

Once we begin to rely upon our reason, and to use our powers of criticism, once we feel the call of personal responsi­bilities, and with it, the responsibility of helping to advance knowledge, we cannot return to a state of implicit submission to tribal magic. For those who have eaten of the tree of knowledge, paradise is lost. The more we try to return to the heroic age of tribalism, the more surely do we arrive at the Inquisition, at the Secret Police, and at a romanticized gangsterism. Beginning with the suppression of reason and truth, we must end with the most brutal and violent destruction of all that is human. There is no return to a harmonious state of nature. If we turn back, then we must go the whole way—we must return to the beasts.

It is an issue which we must face squarely, hard though it may be for us to do so. If we dream of a return to our child­hood, if we are tempted to rely on others and so be happy, if we shrink from the task of carrying our cross, the cross of humaneness, of reason, of responsibility, if we lose courage and flinch from the strain, then we must try to fortify our­selves with a clear understanding of the simple decision before us. We can return to the beasts. But if we wish to remain human, then there is only one way, the way into the open society. We must go on into the unknown, the uncertain and insecure, using what reason we may have to plan as well as we can for both security and freedom. [ch. 10, 218]