There is at the present time a widespread belief that those nations and individuals that remain rational and cool and (within commonsense limits) sceptical, cannot hope for success when they are brought into contact with systems of widely held and fanatically believed dogma. This view is especially common among the sceptics themselves, who are apt to suffer from a kind of fascinated immobility when confronted with the glare of powerful but intellectually limited sectarians. I do not think that history bears out this view of the powerlessness of moderate and limited scientific belief when engaged in conflict with fanaticism; in fact, the exact contrary is nearer to the moral to be drawn from the past. Let us glance at a few illustrations of this theme.

The generals who commanded Roman armies in the days when the Roman empire was most rapidly expanding were for the most part Epicurean sceptics. Their motives were the crudest possible: to plunder the gold reserve of temples, keeping half and distributing the other half among the soldiers; to destroy cities which were commercial rivals of Rome; and so on. The later Romans, pagan and Christian alike, were sunk in superstition; they became increasingly fanatical down to the fall of Constantinople in 1453, and every increase of fanaticism brought fresh defeat.

The same sort of thing is true of the Mohammedans. In the great days of their early conquests, their leaders were sceptics, who had at first opposed the Prophet’s new sect, and only joined in when they saw that there was money in it. This sceptical attitude lasted all through the great days of the Caliphate; when fanaticism began to prevail, loss of military power came with it.

In the sixteenth century, the most fanatical of the great powers was Spain. In spite of every advantage—a brave and warlike population, a superb geographical position, and all the resources of the Indies—Spanish power collapsed. The Jews and Moors, the most industrious and civilized inhabitants of the peninsula, were expelled, to the great detriment of the state. Holland was lost through unwillingness to practise toleration. After the long fruitless devastation of the wars of religion, when the Peace of Westphalia and the collapse of the English puritans had shown that no extremists could win, the greatest share of wealth and power came to Dutch and English latitudinarians. The Revocation of the Edicts of Nantes, by transferring useful industries from France to England, prepared the way for the English defeat in the Seven Years’ War.

At no stage in this long history was victory correlated with fanaticism.

The most recent history shows that in this respect there is no change. The British entered the second world war as a heavy duty, by no means in the spirit of crusade. The Russians and Americans were goaded into self-defence by unprovoked attacks. Only the Nazis were inspired by fanaticism, and their fanaticism contributed not a little to their downfall. After their victory the Allies were surprised to find how little progress the Germans had made towards their construction of atomic bombs. This was largely because they would not employ physicists who were Jews or Anti-Nazis. Their fanaticism also greatly stimulated the resistance movements in conquered territories. I think there can be no doubt that if their rulers had been more rational, they would have won the war, since they would not have attacked Russia or encouraged the Japanese to attack America.

Those who hold that fanaticism can only be defeated by a rival fanaticism cannot appeal to facts in support of their opinion. Victory in modern war depends primarily upon natural resources, industrial and scientific skill, and shrewdness in those who determine policy. Of these requisites, skill and shrewdness are not so likely to be found among fanatics as among men whose outlook is more nearly scientific. Fanatics are unwilling to accept scientific discoveries made by their enemies, and therefore soon fall behind those whose outlook is more cosmopolitan.

Some of those who fear that fanaticism is irresistible do so because they regard complete scepticism as the only alternative. The desirable alternative is not to be sceptical but to be scientific. The sceptic says “nothing can be known”; he is a dogmatist, though a negative one. His creed, we must admit, is paralyzing, and a nation which accepts it is doomed to defeat, since it cannot adduce adequate motives for self-defence. But the scientific attitude is quite different. It does not say “knowledge is impossible,” but “knowledge is difficult.” As against the dogmatist, it holds that nothing can count as knowledge unless it has been submitted to the tests that science has shown to be useful, and even then, it may require correction in the light of fresh evidence. As against the sceptic, it holds that what has emerged from a scientific scrutiny is more likely to be true than what has not, and that in many cases this likelihood is almost certainty; in any event, it is the best hypothesis to accept in practice. The dogmatist accepts one hypothesis regardless of the evidence; the sceptic rejects all hypotheses regardless of the evidence. Both are irrational. The rational man accepts the most probable hypothesis for the time being, while continuing to look for new evidence to confirm or confute it. It is by acting in this way that man has acquired his power over nature, and that the scientific nations have acquired their power over the rest of mankind.

The difference between a rational man and a dogmatist is not that the latter has beliefs and the former has none. The difference is as to the grounds of the beliefs and the way in which they are held. The rational man is prepared to give reasons for his beliefs, and these reasons, except as regards values, are ultimately derived from observation of facts. He will admit that his reasons are not absolutely conclusive, and that new facts may necessitate new beliefs. But he will be prepared to act upon a high degree of probability as vigorously as the dogmatist acts upon what he holds to be certainty. He has, moreover, one great advantage over the dogmatist. When the dogmatist is shown to be wrong—for example, by defeat in war—he suffers a total defeat which can never befall the rational man, who has always admitted that he may be mistaken. Nothing can be more hopeless than a population of disillusioned bigots, who have lost the capacity to be rational, and have no longer any outlet but despair for their irrationality. Such a population has no power of self-direction, and little willingness to accept again the kind of direction from without which has been found to lead astray. The springs of action are dried up, and nothing remains but listless drifting. This is part of the price that has to be paid for indulgence in collective hysteria.

I do not wish to suggest that a man who is scientific to the right extent will be devoid of emotion. Science can deal only with means, not with ends; the ends must be supplied by feeling. For my part, there are certain things that I value; I should mention especially intelligence, kindness, and self-respect. Science cannot prove that these things are good; it can only show how, assuming them to be good, they are to be obtained. To believe in these, or any other ultimate values, without giving a reason for doing so is not irrational, since the matter is not one for rational argument. All rational argument requires premises, without which it cannot start. In matters of fact, the premises come from perception; in matters of value, from feeling. Much of the wide-spread prejudice against the rational comes from failure to realize that rationality is only concerned with what can be proved, not with what proofs have to assume. A man is not unscientific because of his ultimate ends, but because of mistakes as to how to achieve them. Hitler was unscientific because the destruction of Germany, which is what he achieved, was no part of his purpose. To be rational or scientific is only one among virtues; no sane man would pretend that it is the whole of virtue.

Tolerance, as a practical maxim, has two sources: on the one hand, the realization that we may be mistaken; on the other hand, the belief that free discussion will promote the view we favour. This latter opinion must be held by anyone whose opinions are formed on rational grounds. Dogmatists, on the contrary, fear that free discussion would show their beliefs to be groundless, and that is why they always favour censorship. The Western world has learnt tolerance with difficulty, partly by realizing the usefulness of science, which bigots tried to crush. Experience has shown that tolerance and free discussion promote intellectual progress, social cohesion, prosperity, and success in war. I see no reason to suppose that this is going to be any less true in the future than it has been up to the present day. Fanaticisms come and go, and those of our time, like earlier ones, will perish through practical refutation. Tolerance and scientific spirit are among the greatest of human achievements, and I see no reason to think that we are in the process of losing them, or that those who retain them are thereby in any degree weakened in whatever struggle may lie ahead.

*  Bertrand Russell, B.B.C. broadcast transcript, published as “Why Fanaticism Brings Defeat,” The Listener 40 (Sep 23 1948), 452-3  Repr. as “Scepticism and Tolerance,” The Western Tradition, a Series of Talks Given in the B.B.C. European Programme, 1949