George Nathan - The Collected Works of H. L. Mencken

It seems well nigh impossible that a man of Nicolas' age and training should have reasoned so clearly, but the fact remains that he did, and that all of modern philosophy is built upon the foundations he laid. Since his time a great many other theories of knowledge have been put forward, but all have worked, in a sort of circle, back to Nicolas. It would be interesting, perhaps, to trace the course and history of these variations and denials, but such an enterprise is beyond the scope of the present inquiry. Nicolas by no means gave the world a complete and wholly credible system of philosophy. Until the day of his death scholasticism was dominant in the world that he knew, and it retained its old hold upon human thought, in fact, for nearly two hundred years thereafter. Not until Descartes, in 1619, made his famous resolution "to take nothing for the truth without clear knowledge that it is such," did humanity in general begin to realize, as Huxley says, that there was sanctity in doubt. And even Descartes could not shake himself free of the supernaturalism and other balderdash which yet colored philosophy. He laid down, for all time, the emancipating doctrine that "the profession of belief in propositions, of the truth of which there is no sufficient evidence, is immoral"—a doctrine that might well be called the Magna Charta of human thought 3—but it should not be forgotten that he also laid down other doctrines and that many of them were visionary and silly. The philosophers after him rid their minds of the old ideas but slowly and there were frequent reversions to the ancient delusion that a man's mind is a function of his soul—whatever that may be—and not of his body. It was common, indeed, for a philosopher to set out with sane, debatable, conceivable ideas—and then to go soaring into the idealistic clouds. 4Only in our own time have men come to understand that the ego, for all its seeming independence, is nothing more than the sum of inherited race experience—that a man's soul, his conscience and his attitude of mind are things he has inherited from his ancestors, just as he has inherited his two eyes, his ten toes and his firm belief in signs, portents and immortality. Only in our own time have men ceased seeking a golden key to all riddles, and sat themselves down to solve one riddle at a time.

Those metaphysicians who fared farthest from the philosopher of Cusa evolved the doctrine that, in themselves, things have no existence at all, and that we can think of them only in terms of our impressions of them. The color green, for example, may be nothing but a delusion, for all we can possibly know of it is that, under certain conditions, our optic nerves experience a sensation of greenness. Whether this sensation of greenness is a mere figment of our imagination or the reflection of an actual physical state, is something that we cannot tell. It is impossible, in a word, to determine whether there are actual things around us, which produce real impressions upon us, or whether our idea of these things is the mere result of subjective impressions or conditions. We know that a blow on the eyes may cause us to see a flash of light which does not exist and that a nervous person may feel the touch of hands and hear noises which are purely imaginary. May it not be possible, also, that all other sensations have their rise within us instead of without, and that in saying that objects give us impressions we have been confusing cause and effect?

Such is the argument of those metaphysicians who doubt, not only the accuracy of human knowledge, but also the very capacity of human beings to acquire knowledge. It is apparent, on brief reflection, that this attitude, while theoretically admissible, is entirely impracticable, and that, as a matter of fact, it gives us no more substantial basis for intelligent speculation than the old device of referring all questions to revelation. To say that nothing exists save in the imagination of living beings is to say that this imagination itself does not exist. This, of course, is an absurdity, because every man is absolutely certain that he himself is a real thing and that his mind is a real thing, too, and capable of thought. In place of such cob-web spinning, modern philosophers—driven to it, it may be said, in parenthesis, by the scientists—have gone back to the doctrine that, inasmuch as we can know nothing of anything save through the impressions it makes upon us, these impressions must be accepted provisionally as accurate, so long as they are evidently normal and harmonize one with the other.

That is to say, our perceptions, corrected by our experience and our common sense, must serve as guides for us, and we must seize every opportunity to widen their range and increase their accuracy. For millions of years they have been steadily augmenting our store of knowledge. We know, for instance, that when fire touches us it causes an impression which we call pain and that this impression is invariably the same, and always leads to the same results, in all normal human beings. Therefore, we accept it as an axiom that fire causes pain. There are many other ideas that may be and have been established in the same manner: by the fact that they are universal among sane men. But there is also a multitude of things which produce different impressions upon different men, and here we encounter the problem of determining which of these impressions is right and which is wrong. One man, observing the rising and setting of the sun, concludes that it is a ball of fire revolving about the earth. Another man, in the face of the same phenomena, concludes that the earth revolves around the sun. How, then, are we to determine which of these men has drawn the proper conclusion?

As a matter of fact, it is impossible in such a case, to come to any decision which can be accepted as utterly and absolutely true. But all the same the scientific empiric method enables us to push the percentage of error nearer and nearer to the irreducible minimum. We can observe the phenomenon under examination from a multitude of sides and compare the impression it produces with the impressions produced by kindred phenomena regarding which we know more. Again, we can put this examination into the hands of men specially trained and fitted for such work—men whose conclusions we know, by previous experience, to be above the average of accuracy. And so, after a long time, we can formulate some idea of the thing under inspection which violates few or none of the other ideas held by us. When we have accomplished this, we have come as near to the absolute truth as it is possible for human beings to come.

I need not point out that this method does not contemplate a mere acceptance of the majority vote. Its actual effect, indeed, is quite the contrary, for it is only a small minority of human beings who may be said, with any truth, to be capable of thought. It is probable, for example, that nine-tenths of the people in Christendom today believe that Friday is an unlucky day, while only the remaining tenth hold that one day is exactly like another. But despite this, it is apparent that the idea of the latter will survive and that, by slow degrees, it will be forced upon the former. We know that it is true, not because it is accepted by all men or by the majority of men—for, as a matter of fact, we have seen that it isn't—but because we realize that the few who hold to it are best capable of distinguishing between actual impressions and mere delusions.

Again, the scientific method tends to increase our knowledge by the very fact that it discourages unreasoning faith. The scientist realizes that most of his so-called facts are probably errors and so he is willing to harbor doubts of their truth and to seek for something better. Like Socrates he boldly says "I know that I am ignorant." He realizes, in fact, that error, when it is constantly under fire, is bound to be resolved in the long run into something approximating the truth. As Nicolas pointed out 500 years ago, nothing is utterly and absolutely true and nothing is utterly and absolutely false. There is always a germ of truth in the worst error, and there is always a residuum of error in the soundest truth. Therefore, an error is fatal only when it is hidden from the white light of investigation. Herein lies the difference between the modern scientist and the moralist. The former holds nothing sacred, not even his own axioms; the latter lays things down as law and then makes it a crime to doubt them.