Karl Popper · Philosophy
Popper’s ethic for a free society: since we are all fallible, rationality means an openness to being corrected - ‘I may be wrong and you may be right’ - and truth is approached only through free criticism. From this follows his famous paradox: to preserve tolerance, a tolerant society must not extend unlimited tolerance to those who would destroy it.
Popper’s theory of knowledge - that we are fallible, that certainty is beyond us, that we learn only by criticism and the correction of error - is not merely an account of science. It is also, he insisted, an ethic, a way of living with other minds. He called it critical rationalism, and he summed up its whole spirit in a single sentence that he treated almost as a motto. To be rational, in Popper’s sense, is not to possess the truth or to win the argument; it is to hold an attitude of reasonableness - a readiness to listen to criticism, to weigh the other person’s case, to learn from experience, and above all to admit that one might be mistaken. This turns rationality from a private possession into a shared, cooperative enterprise: we approach the truth not alone but together, by pooling our criticisms, and each of us needs the others precisely because none of us can be trusted to catch our own errors.
It is tempting to think that if we can never be certain, then all opinions are equally good and truth is whatever anyone says it is. Popper firmly rejected this slide into relativism, which he regarded as a treason of the intellectuals and a betrayal of reason itself. Fallibilism, he insisted, is not the doctrine that there is no truth, or that one view is as good as another; it is the doctrine that there is an objective truth which we may fail to reach and can never be certain we have reached. The very act of criticism presupposes this: to say ‘you may be wrong’ only makes sense if there is a truth to be wrong about, and to seek to get ‘nearer to the truth’ presupposes a truth to get nearer to. Popper thus occupies a demanding middle ground: he denies us certainty but keeps truth as a regulative ideal, a standard we fall short of but genuinely aim at. We are uncertain, but we are not adrift; some conjectures really are closer to the truth than others, and criticism is how we tell.
From this ethic of reasonableness Popper drew a famous and much-misunderstood conclusion, tucked into a footnote of The Open Society. A tolerant society seems bound, in the name of its own principle, to tolerate everyone - including those who preach intolerance. But here lies a paradox: if a tolerant society extends unlimited tolerance even to movements bent on destroying tolerance, then the intolerant will exploit that forbearance to seize power and crush the tolerant, and tolerance will perish. Unlimited tolerance, in other words, is self-defeating; carried to its logical extreme, it guarantees its own abolition. Popper’s point is not a licence for the tolerant to suppress whatever they dislike - quite the opposite. He argues that we should not suppress intolerant philosophies as long as they can be answered by rational argument and held in check by public opinion; suppression is justified only against those who refuse to meet us on the level of argument at all and answer criticism with fists and pistols. The paradox is resolved not by abandoning tolerance but by refusing to make it unconditional and suicidal.
This is the opening of the lesson. The rest — the dialogue, the primary source, and the recall — is in the app.
You learned that Popper’s critical rationalism is the fallibilist attitude ‘I may be wrong and you may be right, and by an effort, we may get nearer to the truth,’ that we approach truth only through criticism, and that this yields the paradox of tolerance - unlimited tolerance destroys tolerance. Explain the attitude…
Leads to John Stuart Mill.
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