The utility of philosophy… is not confined to speculations which we may hope to see confirmed or confuted by science within a measurable time. Some men are so impressed by what science knows that they forget what it does not know; others are so much more interested in what it does not know than in what it does that they belittle its achievements. Those who think that science is everything become complacent and cocksure, and decry all interest in problems not having the circumscribed definiteness that is necessary for scientific treatment. In practical matters they tend to think that skill can take the place of wisdom, and that to kill each other by means of the latest technique is more “progressive,” and therefore better, than to keep each other alive by old-fashioned methods. On the other hand, those who pooh-pooh science revert, as a rule, to some ancient and pernicious superstition, and refuse to admit the immense increase of human happiness which scientific technique, if widely used, would make possible. Both these attitudes are to be deplored, and it is philosophy that shows the right attitude, by making clear at once the scope and the limitations of scientific knowledge.
Leaving aside, for the moment, all questions that have to do with ethics or with values, there are a number of purely theoretical questions, of perennial and passionate interest, which science is unable to answer, at any rate at present. Do we survive death in any sense, and if so, do we survive for a time or for ever? Can mind dominate matter, or does matter completely dominate mind, or has each, perhaps, a certain limited independence? Has the universe a purpose? Or is it driven by blind necessity? Or is it a mere chaos and jumble, in which the natural laws that we think we find are only a fantasy generated by our own love of order? If there is a cosmic scheme, has life more importance in it than astronomy would lead us to suppose, or is our emphasis upon life mere parochialism and self-importance? I do not know the answer to these questions, and I do not believe that anybody else does, but I think human life would be impoverished if they were forgotten, or if definite answers were accepted without adequate evidence. To keep alive the interest in such questions, and to scrutinize suggested answers, is one of the functions of philosophy.
Those who have a passion for quick returns and for an exact balance sheet of effort and reward may feel impatient of a study which cannot, in the present state of our knowledge, arrive at certainties, and which encourages what may be thought the time-wasting occupation of inconclusive meditation on insoluble problems. To this view I cannot in any degree subscribe. Some kind of philosophy is a necessity to all but the most thoughtless, and in the absence of knowledge it is almost sure to be a silly philosophy. The result of this is that the human race becomes divided into rival groups of fanatics, each group firmly persuaded that its own brand of nonsense is sacred truth, while the other side’s is damnable heresy. Arians and Catholics, Crusaders and Muslims, Protestants and adherents of the Pope, Communists and Fascists, have filled large parts of the last 1,600 years with futile strife, when a little philosophy would have shown both sides in all these disputes that neither had any good reason to believe itself in the right. Dogmatism is an enemy to peace, and an insuperable barrier to democracy. In the present age, at least as much as in former times, it is the greatest of the mental obstacles to human happiness.
The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. If you take your children for a picnic on a doubtful day, they will demand a dogmatic answer as to whether it will be fine or wet, and be disappointed in you when you cannot be sure. The same sort of assurance is demanded, in later life, of those who undertake to lead populations into the Promised Land. “Liquidate the capitalists and the survivors will enjoy eternal bliss.” “Exterminate the Jews and everyone will be virtuous.” “Kill the Croats and let the Serbs reign.” “Kill the Serbs and let the Croats reign.” These are samples of the slogans that have won wide popular acceptance in our time. Even a modicum of philosophy would make it impossible to accept such bloodthirsty nonsense. But so long as men are not trained to withhold judgment in the absence of evidence, they will be led astray by cocksure prophets, and it is likely that their leaders will be either ignorant fanatics or dishonest charlatans. To endure uncertainty is difficult, but so are most of the other virtues. For the learning of every virtue there is an appropriate discipline, and for the learning of suspended judgment the best discipline is philosophy.
But if philosophy is to serve a positive purpose, it must not teach mere skepticism, for, while the dogmatist is harmful, the skeptic is useless. Dogmatism and skepticism are both, in a sense, absolute philosophies; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or of ignorance. Knowledge is not so precise a concept as is commonly thought. Instead of saying “I know this,” we ought to say “I more or less know something more or less like this.” It is true that this proviso is hardly necessary as regards the multiplication table, but knowledge in practical affairs has not the certainty or the precision of arithmetic…
For it is not enough to recognize that all our knowledge is, in a greater or less degree, uncertain and vague; it is necessary, at the same time, to learn to act upon the best hypothesis without dogmatically believing it. To revert to the picnic: even though you admit that it may rain, you start out if you think fine weather probable, but you allow for the opposite possibility by taking mackintoshes. If you were a dogmatist you would leave the mackintoshes at home. The same principles apply to more important issues. One may say broadly: all that passes for knowledge can be arranged in a hierarchy of degrees of certainty, with arithmetic and the facts of perception at the top. That two and two are four, and that I am sitting in my room writing, are statements as to which any serious doubt on my part would be pathological. I am nearly as certain that yesterday was a fine day, but not quite, because memory does sometimes play odd tricks. More distant memories are more doubtful, particularly if there is some strong emotional reason for remembering falsely, such, for instance, as made George IV remember being at the battle of Waterloo. Scientific laws may be very nearly certain, or only slightly probable, according to the state of the evidence. When you act upon a hypothesis which you know to be uncertain, your action should be such as will not have very harmful results if your hypothesis is false. In the matter of the picnic, you may risk a wetting if all your party are robust, but not if one of them is so delicate as to run a risk of pneumonia. Or suppose you meet a Muggletonian, you will be justified in arguing with him, because not much harm will have been done if Mr Muggleton was in fact as great a man as his disciples suppose, but you will not be justified in burning him at the stake, because the evil of being burnt alive is more certain than any proposition of theology. Of course if the Muggletonians were so numerous and so fanatical that either you or they must be killed the question would grow more difficult, but the general principle remains, that an uncertain hypothesis cannot justify a certain evil unless an equal evil is equally certain on the opposite hypothesis.