knowledge. Here we have a limitation that cannot be overleaped. Whatever we come to know, what¬ ever opinions we come to hold, our attention it is that makes all our knowing and all our believing possible; and tbe laws foDowed by this, our own ac- tivitv of attention will thus determine what we are to know and what we are to believe. If things have more than a certain complexity, not only will our limited powers of attention forbid us to unravel this complexity, but we shall strongly desire to believe the things actually much simpler than they are. For our thoughts about them will have a constant ten¬ dency to become as simple and definite as possible. Put a man into a perfect chaos of phenomena, sights, sounds, feelings; and if the man continued to exist, and to be rational at all, his attention would doubt¬ less soon find for him a way to make up some kind of rhythmic regularity, which he would impute to the things about him, so as to imagine that he had dis¬ covered some law of sequence in this mad new world. And thus, in every case where we fancy ourselves sure of a simple law of Nature, we must remember that a good deal of the fancied simplicity may be due in the given case not to Nature, but to the ineradi¬ cable prejudice of our own minds in favor of regular¬ ity and simplicity. All our thought is determined, in great measure, by this law of least effort, as it is found exemplified in our activity of attention.
But attention is not the only influence that goes to transform sense-impressions into knowledge. At¬ tention never works alone, but always in company with the active process of recognizing the present 318 THE RELIGIOUS ASPECT OF PHILOSOPHY \ as in some way familiar, and of constructing in the present ideas of what is not present. At these two other active processes we must very briefly glance.
Recognition is involved in all knowledge. Recog¬ nition does not always mean a definite memory of a particular past experience that resembles a present one. On the contrary, recognition is frequently only a sense of familiarity with something now pres¬ ent, coupled with a more or less distinct applying of some predicate to this present thing. I recognize a horse, a landscape, a star, a friend, a piece of music, a book, when I feel more or less familiar with the impression of the object in question, and when, at the same time, I predicate more or less distinctly something of it. This, I say, is my friend, or the north star, or Webster’s Dictionary, or Smith’s horse. Or, perhaps, in recognizing, I recognize, not merely the whole object, but one of its qualities, or of its relation to other things. Then I say, this is large or small, good or bad, equal or unequal to another thing, and so on. In all these cases, recog¬ nition involves a lively reaction of my mind upon ex¬ ternal impressions. Recognition is not found apart from attention, though attention may exist more or less completely without recognition. Recognition completes what attention begins. The attentive man wants to know, the recognizing man knows, or thinks that he knows. Recognition implies accom¬ panying attention. Attention without recognition implies wonder, curiosity, perplexity, perhaps terror. But what is the law of this process of recognition? Does the process affect the impressions themselves THE WORLD OF THE POSTULATES 319 that are the basis of the recognition? The answer is: Very distinctly, recognition does affect the im¬ pressions. The activity involved in recognition al¬ ters the data of sense, and that in almost every case. Two of the ways in which this alteration occurs are these: (1.) In recognizing, we complete present data by remembered past data, and so seem to expe¬ rience more than is actually given to our senses. Thus, then, in reading, we read over misprints (even against our own will), thinking that we see words when we do not see them, or when we see only parts of them. Again: in listening to an indistinct speaker we often supply what is lacking in the sounds he makes, and seem to hear whole words when we really hear but fragments of words. Or, merely whistling a few notes, we recall to ourselves, and seem to have present, the complex instrumental har¬ mony of some music that we have heard played. Or, in dim twilight, we imagine the form of a man, and seem to see it plainly in detail, when, in fact, a mass of shrubbery, or a coat on a chair, is the one source of our impressions. In all these cases, the activity of recognition alters the data of sense, by adding to them, by filling out the sketch made by them. (2.) However, even the qualities of sense-im¬ pressions are altered according to the way in which we recognize their objects. The colors of a landscape are dimmer, and less significant as colors, so long as we recognize the objects in the landscape. Look under your arm, with head inverted, and the colors flash out with unwonted brilliancy. For when you so look, vou lose sight of the objects as such, and 320 THE RELIGIOUS ASPECT OF PHILOSOPHY give your attention solely to the colors. Mistake a few brown leaves in some dark corner of a garden for some little animal, and the leaves take on for the moment the distinctive familiar color of the animal; and when you discover your blunder, you can catch the colors in the very act of fading into their dull, dry-leaf insignificance. Many facts of this sort are recorded by psychologists and by artists, and can be observed by any of us if we choose. To separate a sensation from its modifications that are produced by recognition is not a little difficult.
Now, in both these kinds of alteration a law is observed, very similar to the one previously noted. The alterations of the data of sense m the moment of recognition are alterations in the direction of simplic¬ ity and definiteness of consciousness. The present is assimilated to the past; the new is made to seem as familiar as possible. This reaction of the mind upon new impressions is easily seen in our thoughts and words in the first moment of great surprise or fright. When Macbeth turns from his door to the table, and sees the ghost of Banquo in his chair, his first words are not the “ Avaunt, and quit my sight 1 ” wherewith he greets the second appearance of the ghost, nor yet even the “ Which of you have done this? ” that he utters as soon as he recovers himself. No: his first conscious reaction, in pres¬ ence of the horrible impression, is a quiet remark, “ The table ’s full.” And when they tell him that there is a place reserved, he persists with a “ Where? ” In this scene, Shakespeare’s instinct is perfectly accurate. Our effort always is to make THE WORLD OF THE POSTULATES 321 the new as familiar as possible, even when this new is inconceivably strange. It takes us some time to realize, as we say, a great change of any sort. Rec¬ ognition, however, is yet further modified by the in¬ terest with which we at any moment attend to things. But when we speak of interest, we are led to the third kind of active modification by which our minds determine for us what we know.
At every moment we are not merely receiving, at¬ tending, and recognizing, but we are constructing. Out of what from moment to moment comes to us, we are building up our ideas of past and future, and of the world of reality. Mere dead impressions are given. We turn them by our own act into symbols of a real universe. We thus constantly react upon what is given, and not only modify it, but even give it whatever significance it comes to possess. Now this reaction takes a multitude of forms, and cannot be fully discussed without far more than our present space. But we can name one or two prominent modes of reaction of mind upon sense-data in this province of mental life.
1. Definite memory is possible only through pres¬ ent active construction from the data of feeling. Nothing can come to us certifying for itself that it formed a part of our previous experience. M hen we know a thing as past, we actively project our idea of it into a conceived past time. Without this active interference of our own minds, eveiy thing would be but a present, and there would be no time for us, only fleeting life from moment to moment.
2. Definite belief in external reality is possible 322 THE RELIGIOUS ASPECT OF PHILOSOPHY only through this active addition of something of our own to the impressions that are actually given to us. No external reality is given to us in the mere sense-impressions. What is outside of us cannot be at the same time within us. But out of what is in us, we construct an idea of an external world. To be sure this belief needs higher justification, like all other beliefs. But at the outset it is just an activ¬ ity of ours.
3. All abstract ideas, all general truths, all knowl¬ edge of necessary laws, all acceptance of doctrines, begin in like fashion, through an active process com¬ ing from within. Change the fashions of our men¬ tal activity, and nobody can tell how radically you would change our whole conception of the universe.
4. All this active construction from sense-impres¬ sions expresses certain fundamental interests that our human spirit takes in reality. We want to have a world of a particular character; and so, from sense-impressions, we are constantly trying to build up such a world. We are prejudiced in favor of regularity, necessity, and simplicity in the world; and so we continually manipulate the data of sense for the sake of building up a notion of a regular, necessary, and simple universe. And so, though it is true that our knowledge of the world is deter¬ mined by what is given to our senses, it is equally true that our idea of the world is determined quite as much by our own active combination, completion, anticipation of sense experience. Thus all knowing is, in a very deep sense, acting; it is, in fact, react¬ ing and creation. The most insignificant knowledge THE WORLD OF THE POSTULATES 323 is in some sense an original product of the man who knows. In it is expressed his disposition, his power of attention, his skill in recognition, his interest in reality, his creative might. Exact knowledge is, in fact, best illustrated by cases where we ourselves make what we know. So only is mathematical knowledge possible; mathematical ideas are all prod¬ ucts of a constructive imagination. And so it is in all other thought-life. Mentally produce, and thou shalt know thy product. But we must remember, for what we produce we are in some sense morally responsible; and thus, in discussing the nature of knowledge, we are trespassing on the border-land of ethics.
To sum up all in a few words: Plainly, since ac¬ tive inner processes are forever modifying and build¬ ing our ideas; since our interest in what we wish to find does so much to determine what we do find; since we could not if we would reduce ourselves to mere registering machines, but remain always build¬ ers of our own little worlds, — it becomes us to con¬ sider well, and to choose the spirit in which we shall examine our experience. Every one is certain to be prejudiced, simply because he does not merely re¬ ceive experience, but himself acts, himself makes ex¬ perience. One great question for every truth-seeker is: In what sense, to what degree, with what motive, for what end, may I and should I be prejudiced? Most of us get our prejudices wholly from the fash¬ ions of other men. This is cowardly. We are re¬ sponsible for our own creed, and must make it by our own hard work. Therefore, the deepest and 324 THE RELIGIOUS ASPECT OF PHILOSOPHY most important of all questions is the one, “ For what art thou at work V' It is useless to reply, “ 1 am merely noting down what I find in the world. I am not responsible for the facts' ’ The answer is, “ A mere note-book thou art not, but a man. These are never simply notes; thy thoughts are always transformed reality, never mere copies of reality. For thy transforming activity, as well as for thy skill in copying, thou art answerable.”
V.
V.
It is not then that postulates occur here and there in our thoughts, but that, without postulates, both practical life and the commonest results of the¬ ory, from the simplest impressions to the most valu¬ able beliefs, would be for most if not all of us ut¬ terly impossible; this it is which makes active faith so prominent a subject for philosophical considera¬ tion. An imperfect reflection makes that appear as blind faith which ought to appear as postulate. In¬ stead of saying that he takes all these things on risk, and because they are worth the risk, the natu¬ ral man is persuaded by such imperfect reflection to say that he trusts very ardently that he is running no risk at all. Or again: the natural man is moved to fear any examination into the bases of his thought, because he does not wish to discover that there is any risk there. And so we live dishonestly with our thoughts. Where there is a deeper basis, that involves more than mere risk, let us find it if we can. But where we have nothing better than active faith, THE WORLD OF THE POSTULATES 325 let us discover the fact, and see clearly just why it is worth while to act in this way.
To speak more particularly of the postulates of developed science. The ancient discussions about the basis of physical knowledge of all sorts have had at least this as outcome, that it is useless to pre¬ tend to make science of any sort do without assump¬ tions, and equally useless to undertake the demon¬ stration of these assumptions by experience alone. No one has ever succeeded in accomplishing such a thing, and the only difference among thinkers about these assumptions is that some think it worth while to seek a transcendental basis for them all, while others insist that a transcendental basis is as impos¬ sible as a purely experimental basis is inadequate, and that in consequence we can only use the form of threat and say: Unless you make these assumptions, the spirit of science is not in you. As for the exact form that in more elaborate scientific work ought to be taken by these postulates, opinion differs very much, but an approximation to their sense may be attempted very briefly as follows.
In addition to those postulates that, as we have seen, accompany and condition all thinking alike, science may be considered as making a more special assumption. This assumption has been well defined by Professor Avenarius, in his well-known essay on “ Die Philosophic als Denken der Welt Gemass dem Princip des kleinsten Kraftmasses.” He regards it as an outcome of the general law of parsimony that governs all mental work. The world of phenomena is conceived at any stage in the simplest form, and 326 THE RELIGIOUS ASPECT OF PHILOSOPHY the reality that we accept is for us at any time the simplest description of the phenomena as known to us. To put this view in our own way, we might say that the world is scientifically viewed as a per¬ fectly united whole, which would, if fully known, fully satisfy our highest mental desire for continuity and perfect regularity of conception. Therefore it is that the “ universal formula ” of the last chapter is a conception that expresses the scientific ideal. With less perfection, harmony, and unity of thought about the world, science will never rest content so long as she continues to be science. But for this very reason science postulates that this perfect order must be already realized in the world. It is not merely that this order is the practically unattainable but still necessary ideal for our reason; but we must postulate that this order is already present in things, far off as our thought is from it. This pos¬ tulate gives life to our scientific thought. Without it our search for an order that need not exist is meaningless play.
This postulated order, however, if found, would mean for us relative simplicity and economy of con¬ ception. The infinite mass of phenomena would be conceived as one whole. The maximum of wealth of facts would be grasped with the minimum of men¬ tal effort. We postulate after this fashion that the world loves parsimony, even as we do.
To illustrate by the case of one science. A great master of mechanical science has called it the science which gives the simplest possible description of the motions in the world. If we accept this account of THE WORLD OF THE POSTULATES 327 mechanics, we are at once puzzled by the fact that most mechanical theories make assumptions about the forces at work in the world, and that all of them predict coming facts. But forces form no part of the experience or of the mere description of motion. And the future is not yet given to be described. How then does all this agree with the definition in question? Very well indeed. For those who as¬ sume, forces to explain given motions, always assume just those forces that will directly explain, not any description at random of the motions given in expe¬ rience, but the simplest possible description. Any motion being relative, never for our experience abso¬ lute, we can assume at pleasure any point in the world as the origin or point of reference that shall be regarded as at rest, and so we can get an infinite number of descriptions of any given motions. Wb can make any object in the world move at any de¬ sired speed or in any desired direction, simply by altering the origin to which we shall choose to refer its motion in our description thereof. But all these possible descriptions are not equally useful for the purposes of the science. Some one of them is the simplest for all the motions of the system in ques¬ tion; and this we regard as best expressing the ac¬ tual natural truth in the matter. The assumption of just such forces as would explain this simplest system of motions as described, satisfies us. We say, these forces are the real ones at work. But still we know that the forces assumed only express in another form the fact that the description in ques¬ tion is the simplest. Is this, however, really all that 328 THE RELIGIOUS ASPECT OF PHILOSOPHY the science does with the given motions? No, one thing more the science assumes, namely, that if the system of motions in question is not subject to any external influence, it will remain fundamentally and in deepest truth the same in future, that is: The simplest description of the given motions in a sys¬ tem of bodies that is wholly independent of the ac¬ tion of bodies without the system, this description is permanent for all states of the system. This assumption is needed before mechanical science can venture on any prediction, or beyond mere descrip¬ tion of past and present motions. This is the pos¬ tulate of the uniformity of nature in its mechanical shape.1 The complete present description of the world would reveal the whole future of the world.
"WTiat, however, does this postulate of uniformity express for our thought? What is the philosoph¬ ical outcome of it? It expresses for our thought the demand that nature shall answer our highest intel¬ lectual needs, namely, the need for simplicity and absolute unity of conception. Mechanical science can no more do without this assumption than can any other science.
The ground that we have here very briefly passed over is known to all readers of modern controversy. We can only add our conviction that, as far as it goes, the foregoing view is a perfectly fair one. Whether or no there be any deeper basis for this Professor Clifford, in his essay on Theories of the Physical Forces, in his Lectures and Essays, vol. i., p. 109 sqq., has under¬ taken to reduce this postulate to the general one of Continuity. The philosophical outcome would be the same.
THE WORLD OF THE POSTULATES postulate, it is sure that science makes the postulate, and does not give any deeper basis for it. For nat¬ ural science it is a faith.
Now this faith, not blind faith but postulate, not basely submitted to merely because we must submit to it, but boldly assumed because we think it worth the risk, wherein does it differ from what our funda¬ mental religious faith would be if we made of that also no mere dogmatic creed, but a general assump¬ tion, no mere passive trust, but an active postulate? Beneath all the beliefs that we could not demon¬ strate in our last chapter, lay the determination not so much to prove one cast-iron system of dogmas, as to find some element of reality that should have an infinite worth. The world should be at least as high as our highest conception of goodness. And to this end the partial evil should be in deepest reality universal good, even though our imperfect eyes could never show to us how this could be, — could never see through the illusion to the “ image¬ less truth ” beneath. Therefore, although we vainly sought among the Powers of the world for proof of all this, may we not still hope to approach the Eternal Reality with these postulates, and to say: “Though thou revealest to us nothing, yet we be¬ lieve thee good. And we do so because this faith of ours is a worthy one.” Possibly then our Religion will be just the highest form of our conduct itself, our determination to make the world good for our¬ selves, whatever baseness experience shows us in it. Then we can say: Just as science is undaunted by the vision of the world of confusion, so shall our re- 330 THE RELIGIOUS ASPECT OF PHILOSOPHY ligious faith be undaunted by the vision of the evil of the world. We shall war against this evil in the trust that the highest reality is not against us, but with us, just as we try to comprehend the world with the faith that the highest reality is in conformity with our private reason. In both cases we take the risk, but we take the risk because it is worth taking, because to take it is the highest form of activity. As the faith of science helps to make life rational, so the religious faith helps to make life in the high¬ est sense moral, by insisting that the ideal labors of our moral life are undertaken not alone, but in har¬ mony with the world as known to the Infinite.
To make the parallel a little clearer, we may say that science postulates the truth of the description of the world that, among all the possible descrip¬ tions, at once includes the given phenomena and at¬ tains the greatest simplicity; while religion assumes the truth of the description of the world that, with¬ out falsifying the given facts, arouses the highest moral interest and satisfies the highest moral needs.
All this has often been said, but it has not always been clearly enough joined with the practical sug¬ gestion that if one gives up one of these two faiths, he ought consistently to give up the other. If one is weary of the religious postulates, let him by all means throw them aside. But if he does this, why does he not throw aside the scientific postulates, and give up insisting upon it that the world is and must be rational? Yea, let him be thorough-going, and, since the very perception of the walls of his room contains postulates, let him throw away all these THE WORLD OF THE POSTULATES 331 postulates too, and dwell in the chaos of sensations unfriended. There is no reason why he should not do this unless he sees a deeper foundation for his postulates. We have no mere dogmas to urge here. Let one abandon all mere postulates if he has not the courage to make them, but then let one consist¬ ently give them all up. The religious postulates are not indeed particular creeds. One may abandon creeds of many sorts, and yet keep the fundamental postulate. But if he abandons the fundamental pos¬ tulate of religion, namely, that universal goodness is somehow at the heart of things, then he ought consistently to cease from the fundamental postu¬ late of science, namely, that universal, order-loving reason is somehow the truth of things. And to do both is to lack the courage of rational and of moral life.