Part 10
Naturally, then, we wish to know what is "sufficient evidence" in the eyes of science, since everything, we are told, depends on that. The reply is brief: whatever is based on the Uniformity of Nature has sufficient evidence. If we are inclined to be puzzled by the "Uniformity of Nature," we are soon reassured; it is literally the most ordinary thing in the world, there is no difficulty about it. Man is born into a world in which changes are unceasingly taking place. Some things change even as the clouds shift--every second, and in a way patent to all beholders. Others change imperceptibly and with great slowness, as _e.g._ the level of the dry land or the shape of the coast-line. But all things change, _πάντα ῥεῖ_. Nothing abideth long in one stay. It is these changes which bring all things good to man, and also all things ill. If, then, man is to survive, he must learn to evade the latter changes, which threaten to crush him, and he must be there in time to profit by the former. Such was the problem presented to primitive man, and such it still is for every one of us to-day: the successful man is the one who is beforehand with the world, and, if he is beforehand it is because he has learned to read the signs of the times and the seasons. In a word, he has learned to recognise that changes are not always mere chances, that some changes are uniformly preceded by certain others, and may consequently be foreseen. In the beginning the changes that man can forecast are few indeed: his prevision is no greater than the brute's. The child does not foresee that fire will burn; he learns by experience. And whatever man can forecast, he has learned it all by experience. It is a slow way of learning, it has taken man thousands upon thousands of years to learn what he knows now; still he has learned to know the causes of countless things, to control the causes and to anticipate the effects of many. But more important, more valuable than all his experience and all his knowledge of what produces what, of what uniformly precedes or follows what, is the final and comprehensive truth which at last he reaches, that nothing happens arbitrarily, that everything in nature is uniform. That, the Uniformity of Nature, is the great truth in which all others are summed up: to its establishment have gone the labours of all past generations of mankind, to its support the whole experience of the race contributes. It is the truth of truths, the test of truth: whatsoever is established on it shall not be shaken, whatever contravenes it shall not endure.
The Uniformity of Nature is the base not only of all science, but of every act of reason in the most commonplace affairs of ordinary life; and, though you may not know it, you assume it every moment. Why are you sure that the sun will rise to-morrow? Because Nature is uniform. Why do you know that fire will burn? Because Nature is uniform. Why that all men are mortal? Why that a cause will always produce its effect? Because of the Uniformity of Nature. For each and all of these beliefs the evidence is sufficient; it is the Uniformity of Nature. How different, says the man of science, is the procedure of science, that is of common sense, from the unscientific methods of theology! Why do we believe that the earth will bring forth her kindly fruits in due season? Because it is God's will? That is a hypothesis; it may be true or it may not; it cannot be proved or disproved; there is no evidence against it, but there is no evidence for it. Very different is the answer of science and common sense: it is that the earth will produce crops in accordance with certain natural causes, mechanical and chemical. That also is a hypothesis which may or may not be true. Yes, but it is one for which there is some evidence--the Uniformity of Nature. In the same way, if anyone were to say that the result of the next general election depended not on the electors but on the planets, we should decline to believe him, because there is no evidence to show that the planets have anything to do with it, and there is good evidence for believing that the votes of the electors have. In fine, the teaching of science is: demand sufficient evidence for everything, and always remember that by sufficient evidence is meant the Uniformity of Nature.
This sounds so simple and so convincing that we are tempted to try it. But first let us make sure that we have learned our lesson properly. In the course of long ages mankind has slowly accumulated enough experience to warrant the confident belief that Nature is uniform. Now, primitive man was of course a savage, and knew nothing of the Uniformity of Nature; he therefore could not have had sufficient evidence for believing anything in his experience. But it is on the accumulation of such experiences--every one of which we must reject because they were not based on the Uniformity of Nature--that our belief in the Uniformity of Nature is supposed to rest. In other words, it is based on them and they were based on nothing. This result of acting strictly up to the principle of not suffering anything to pass without sufficient evidence seems somewhat discouraging, until the man of science comes to our rescue and reminds us that just as we, without knowing it, have acted all our lives on the tacit assumption that Nature is uniform, so did primitive man; and that consequently there really was sufficient evidence and scientific proof for the savage's experiences, though of course he could not have framed it in words; and so, the bases of the Uniformity of Nature are really quite sound. But even now we are not altogether out of our difficulties, for granted that the savage, like ourselves, tacitly assumed Nature to be uniform, was there sufficient evidence for the assumption? and if so, what was the evidence? It could not be the Uniformity of Nature, because that is just the question; and, if it was anything else, it was not sufficient evidence.
It really seems rather difficult to get sufficient evidence for the axiom, viz. the Uniformity of Nature, on which the whole of science is built. And yet we must have sufficient evidence for it, or else we shall have to conclude that Science has no more logical foundation than Religion.
But once more the man of science comes to our assistance and explains that in the beginning, before the Uniformity of Nature is proved, it is only probable that what has once happened will happen again in similar circumstances, and at first perhaps not very probable; but when wider and wider experience still shows that what has once happened does actually happen again under the same circumstances, the Uniformity of Nature becomes more and more probable, until at last, if not actually proved, it is still the most probable hypothesis that we possess or can possess: "our highest and surest generalisations remain on the level of justifiable expectations; that is, very high probabilities."[26]
Now, with all respect to logicians like John Stuart Mill, and men of science like Huxley, we must point out that this begs the whole question. If we assume that Nature is uniform, then it is probable that what has often happened will happen again. But if we do not assume that Nature is uniform, then the repeated occurrence of a thing does not make it in the least probable that it will occur again. To assume without proof that Nature is uniform is to ask us to accept a statement without evidence, which, if we have learnt the lesson of science, we can hardly do. On the other hand, if we begin with the admission that Nature may or may not be uniform, but that, to begin with, we no more know whether it will actually prove to be uniform than we know whether a penny, when we are about to toss it, will fall head or tail; then, according to the mathematical theory of probability, it matters not how many times you toss the penny, the chances next throw are exactly the same as they were at the first throw--it matters not how many times Nature has proved uniform in the past, she is no more likely to prove uniform to-morrow than she was on the first of days. If it is really an open question at the beginning whether Nature is or is not uniform, it remains an open question to the end. The man of science need not admit that it is an open question, if he does not want to do so; but if he does admit it, then let him stick to it throughout; and let him reflect that if he begins by admitting it and ends by denying it, he has but gradually retracted his own free admission, and unconsciously been betrayed into denying what he began by admitting to be true.
The fact of the matter is that the axioms of science--the Uniformity of Nature and the Law of Universal Causation--not only are not proved by what experience we have had of them, but "cannot be proved by any amount of experience."[27] Not only can they not be proved by any amount of experience, they are incapable of being demonstrated at all: "they are neither self-evident nor are they, strictly speaking, demonstrable."[28] If, then, they are not and cannot be proved either by experience or in any other way, on what does the man of science ground his belief in them? On Faith. "The ground of every one of our actions, and the validity of all our reasonings, rest upon the great act of faith, which leads us to take the experience of the past as a safe guide in our dealings with the present and the future."[29]
FOOTNOTES:
[25] HUXLEY, _Darwiniana_, p. 361.
[26] HUXLEY, _Science and Christian Tradition_, p. 205.
[27] HUXLEY, _Evolution and Ethics_, p. 121.
[28] HUXLEY, _Method and Results_, p. 61.
[29] HUXLEY, _Science and Christian Tradition_, p. 243.
IX.
CONSEQUENCES
In the last chapter, impressed by the doctrine that there is no "source of truth save that which is reached by the patient application of scientific methods,"[30] we patiently applied those methods to the foundation of science itself; and we were rewarded by the discovery that scientific, like religious, truth has its source in Faith. But the end of our difficulties is not yet.
A man may put his faith in science, if he will, "but let him not delude himself with the notion that his faith is evidence of the objective reality of that in which he trusts."[31] About that we feel no difficulty: faith begins not merely with ignorance, but with the frank confession that we know we are ignorant, but we wish to believe, in spite of the absence of evidence. There is no evidence to show that Nature is uniform or science true, but we do not mind that: we are quite determined to believe, evidence or no evidence. That is easy enough for us, who are not scientific; but "scientific men get an awkward habit--no, I won't call it that, for it is a valuable habit--of believing nothing unless there is evidence for it; and they have a way of looking upon belief which is not based upon evidence, not only as illogical, but as immoral."[32] This is, if not awkward, at least puzzling, since science is based on a belief in the Uniformity of Nature, for which there is no evidence.
"It is, we are told, the special peculiarity of the devil that he was a liar from the beginning. If we set out in life with pretending to know that which we do not know; with professing to accept for proof evidence which we are well aware is inadequate; with wilfully shutting our eyes and our ears to facts which militate against this or that comfortable hypothesis; we are assuredly doing our best to deserve the same character."[33] That also is puzzling. Science sets out in life with assuming, by a "great act of faith," that Nature is uniform. She is well aware that the evidence for this assumption is inadequate, that no amount of experience could prove it; but, if she is to start at all, she must make the assumption, so she proceeds to act as though it were proved, as though she knew what she does not know. These are facts; and we take it for granted that no one will wilfully shut his eyes and his ears to them, even if he has some comfortable hypothesis against which they seem to militate.
Again, belief in science is based not on any ground of reason, but upon "the great act of faith" which leads the man of science to assent to it. It is therefore again puzzling to learn that "assent without rational ground for belief is to the man of science merely an immoral pretence," and that "scepticism is the highest of duties; blind faith the one unpardonable sin."[34]
But the reader has probably already correctly divined the solution of these puzzles: the passages quoted above are not intended to apply to science. The blind faith which is illogical, immoral, a pretence and a lie, is, of course, not faith in science, but some other kind, which may therefore be dismissed; and we may start once again with the happy feeling that there is one kind of faith at least which is logical, moral, and real and true.
It is, then, quite honest and logical to have faith sometimes; and, without evidence, to believe some things, _e.g._ the Uniformity of Nature. Here, however, some readers may interpose with the objection that the man of science has not proved that _his_ faith is logical and moral, and real and true--he has simply assumed it. Quite true; but that _is_ his faith and we must respect it, as we respect any man who holds fast to what he honestly believes to be the real truth. We do not imagine he could believe it if he thought it a pretence or a lie. And we do not call upon him to prove it before we believe him--still less to prove it before he believes it himself.
It is, therefore, we repeat, quite reasonable to believe in the Uniformity of Nature without evidence. The reluctance that is genuinely felt by many minds to take up this position is probably due to a feeling that if we may believe in one thing without evidence, then anyone may believe in anything he likes. And it would not be quite fair to make the rejoinder, What does that matter to you, as long as you are free to believe what you think right? The tendency to dogmatise, and to be intolerant of opinions not our own, is, indeed, strong enough in all of us to make us stand somewhat in dismay of a line of argument which seems to indicate not merely that other people have a right to differ from our opinions, but may quite conceivably be right in so differing. Still, this tendency does not wholly account for our reluctance. That reluctance has, in part at least, a nobler origin than narrow-mindedness and the ignorance which knows not that it is ignorance. It does matter to us what our fellow-men believe. Still more does it matter how and why they choose their beliefs.
The reluctance to admit that it is permissible to believe without evidence even in a truth so undisputed as the Uniformity of Nature, is also in part due to yet another cause. It is felt that to admit belief without regard to evidence is to invite intellectual anarchy, and to leave mankind the helpless prey of ignorance, error, and superstition. Hence, in many candid souls, a lamentable feeling of distraction and hopelessness: to abandon their old faith, even if it has no evidence, is almost more than they can bear; to retain it, knowing that it has no evidence, is to open the floodgates of a saturnalia of unreason by which the foundations of civilisation would be swept away. Hence, too, the zeal with which other minds call for the destruction of every belief, but especially religious belief, not based on evidence, and with which they denounce faith as the one unpardonable sin.
But the error into which both classes of mind fall is a simple one. It consists in imagining that if we take one thing on faith, because there is no evidence, therefore we may believe anything, even if the evidence is conclusive against it--that if we once accept faith, we must for ever abjure reason. The error has been clearly exposed by Professor Huxley, who, after pointing out that reason--ratiocination--is based on faith, says, "But it is surely plain that faith is not necessarily entitled to dispense with ratiocination because ratiocination cannot dispense with faith as a starting-point; and that because we are often obliged, by the pressure of events, to act on very bad evidence, it does not follow that it is proper to act on such evidence when the pressure is absent."[35]
It seems, then, a piece of alarmist exaggeration to say that if we admit one thing, _e.g._ the Uniformity of Nature, without evidence, we forfeit the right ever again to ask for evidence for any other statement: on the contrary, whenever evidence can be got, we must get it and abide by it. But this only shows that no disastrous consequences will necessarily ensue, if we frankly admit what in any case is the fact, viz. that there is no evidence for the postulate on which all science is built. You will not have committed high treason against the best interests of mankind by acting, in this case, on the principle that a man may sometimes believe a thing on evidence which, he is well aware, is insufficient, or on no evidence at all. On the other hand, in another case, to act on the principle might be, if not high treason, at least mischievous.
It seems, then, first, that there are some things which a man may believe without evidence, and some which he may not; and, next, that he may not believe things the consequences of which would be disastrous or mischievous. But now what of the things not mischievous or disastrous? On what principle are we to choose amongst them? Let us once more follow our guide, the man of science, and ask him on what principle he elected to believe that Nature was uniform, rather than that she was not. I imagine it was once more on the ground of the consequences: grant that Nature is uniform, and then all the marvellous discoveries, the revelations of the past and prophecies of the future, which science has made, become things that we can reasonably believe in. Refuse to believe, withhold your faith, and then you have no reason to believe anything whatever, thought and action alike are paralysed. It is between these consequences that we have to choose. Our choice is an act of will; and it is on our will that our beliefs and our actions depend.
In science, then, we are offered the alternatives: either believe without evidence that Nature is uniform, or renounce all that science has to give. We want to be scientific, so we choose the former. We believe (in science) because we want to believe, not because we have any evidence. To say that we may yield to the impulse to have faith, without being unscientific, is to understate the case: we cannot be scientific without faith.
In logic, whether inductive or deductive, the case is the same. We must either believe without evidence in the axioms on which reason is based, or forego reason altogether. We want to be reasonable, so we choose to accept the axioms. But our choice is not the least evidence or proof that they are true. We believe they are true, because we wish to believe that they are true. There is no reason except there first be faith.
With morality the case is not otherwise. We believe in the principles of morality, not because we can prove them, or bring evidence to show that a man ought to do what is right, but because we wish to believe, and because we have faith in the right. There is no morality except first there be faith.
We are nothing, know nothing, can do nothing without faith. And it is not in the dead past, which is what we mean by "evidence," but in the living future that faith has its well-springs. It is because we wish to do right henceforth that we put our faith in right-doing. It is not the ghosts of our misdeeds, rising from the charnel-house of the past in evidence against us, that give us good hope of the future--it is faith, not built on evidence, on a past that cannot be altered, but on hope, on the future, on what shall be as we will it.
The future is uncertain. But that is no reason why you should be. There is no evidence that we shall succeed, that logic can be trusted, or that science is true. But fortunately it is possible to be certain without evidence. In commenting on the text "Faith is the assurance of things hoped for, the proving of things unseen," Professor Huxley says, "I fancy we shall not be far from the mark if we take the writer to have had in his mind the profound psychological truth, that men constantly feel certain about things for which they strongly hope, but have no evidence, in the legal or logical sense of the word; and he calls this feeling 'faith.'"[36] It is a profound psychological truth, and by the aid of the theory of evolution we may understand why it is so deep-seated in the mental and moral constitution of man. Primitive man can have had no extensive "evidence" of any kind to go upon in regulating the conduct of his daily life; and in all probability exercised but little power of criticism in judging the value of what evidence he had. At the same time, if he was to survive at all in the struggle for existence, he had to act and to act promptly. Fortunately for him it was possible to feel certain about things for which there was no evidence, _i.e._ to have faith. And he survived in consequence--in virtue of the law of the survival of the faithful, a law whose operation is possibly not confined to this world.
On the theory of evolution, again, man's wants must have aided him in the struggle for existence; and no evolutionist will doubt that the desire to be rational and to do that which is right has assisted man in his upward struggle. The victory has remained with those who have been contented to feel certain about things for which they had no evidence, and to act on faith. It is those who hesitate to do right until sacrifice of self is proved to be reasonable, who lose their chance, and consequently have been and are being, though slowly, weeded out. Those who have yielded to their inner impulse to believe, without evidence, have evidently been the better fitted to their environment, and the more in harmony with the ruling principle of the cosmos and its evolution.
Thus far in this chapter there has been no explicit mention of religious faith. We began with the fact that faith is indispensable to science as its starting-point. We do not wish to end with the suggestion that scientific faith can or ought to be stretched so as to make religious faith its logical or necessary consequence. On the contrary, the man who by a great act of faith accepts the Uniformity of Nature without evidence, and then resolves never to accept another statement without evidence, is quite safe: no one can make him believe in religion as long as he holds to his resolve--or in morality either. There is no evidence--and therefore he cannot believe--that a man ought to do what is right. If he does ever depart from his resolve as regards morality, it will be because in his heart--with its reasons which his reason knows not of--he wants to do right, not because there is any evidence.