Introduction

Philosophy is a subject which everyone in the end defines for himself, and in view mainly of the particular philosophy which he himself has formed. We labour as philosophers under the peculiar and paradoxical difficulty, that we cannot properly state the questions which we are investigating until we are prepared with some kind of answer to them. Even if we could all agree on some abstract statement of the problem before us, and the methods available for solving it, the formulae used would probably mean very different things in the different mouths which should repeat them. Hence the Introduction to a work like the present must make no pretence to lay down the philosophical problem once for all as it must present itself to every inquirer. It describes the subject only as it has formed itself in the mind of the writer during the course of reflections explained in the following chapters, and it pretends to no value except that of serving in some degree as a guide in following the line of thought in those chapters. It explains, in a word, the rules of the game which the reader is invited to play. Whether the game is or is not worth playing, and whether it is better or worse than any other game which might be played by other rules, can be determined only by the final result. My business, then, in the present Introduction is not to decide whether there can or cannot be a theory of knowledge, or what subjects must or must not be treated under this head, but merely to explain to the reader what he is to expect in the coming chapters, leaving those chapters to justify themselves.

With regard to any statement we like to take, there seem to be three questions possible. We may ask what is meant; on what grounds is it stated; is it true? The first of these we may call technically the question of meaning or content. If you make a statement you must, of course, state something, and this something is what your assertion contains—it is its content. The answer to the first question, then, consists in assigning the content of the statement, whether by mere repetition, or translation, or explanation, or in any other way.

The second question might be said to assume too much. Perhaps some statements have no grounds at all; and in a strict sense of the word this may be true. But every statement—even a lie—is motived in some way or another. It is uttered for a purpose, or is brought about by some psychological cause, just like any other human act. And if for the present we do not discriminate between these processes by which a statement may be brought forth, we may assume that every statement has some grounds or other. And, in fact, it is our constant employment to examine the grounds of this statement or that.

This investigation is connected at once with the third question—whether the statement is true or false. Every statement falls into one or other of these two classes, while many appear, for our sins, to fall into both at once. But to have some degree of truth or falsity is the common characteristic of all statements, differentiating them from other forms of expression—prayers, commands, questions, aspirations, etc.

Now these three questions, which are asked by special inquiries with regard to this or that statement, or this or that class of statements, are asked by our branch of study with regard to statements, judgments, assertions, or whatever we please to call them, in general. The conditions, the content, and the validity of our knowledge as a whole, are the questions with which we have to deal. Each of them demands a word of explanation. I begin with the conditions of knowledge. In ordinary life we are content with a very little in the way of proof. If I am told that there will be an eclipse of the moon to-morrow night, I take the statement as sufficiently “proved” by a reference to Whitaker's Almanack. If I am studying astronomy, I take the question a little further, and endeavour to understand the mass of observations and calculations by which the eclipse is determined. But here again, though no longer content with the ipse dixit of Whitaker, there are a good many steps in the train of proof which I should probably take for granted, but which would repay some examination. The demonstration will assume, for example, certain geometrical theorems; and if we once begin to inquire into them and their grounds, we shall open up quite a new field of arguments, and perhaps of assumptions. It depends, once more, on the accuracy and veracity of a number of observers, and perhaps on the make of their instruments; and here again points are suggested which might plunge us into a lengthy discussion. We may cut this short by remarking that in any proof, scientific or otherwise, we ordinarily offer such grounds as satisfy ourselves, and into the truth of these grounds we do not further inquire. And this is the right practical attitude. But it is just here that the theory of knowledge, for reasons of its own, takes up the question. It cross-examines the witness whom everybody else leaves alone. It endeavours to give as complete an account as possible of all the factors involved in the ground of any statement, leaving no assumption unexpressed, nor, if possible, untested. Briefly, then, on this head the theory of knowledge aims at completing the inquiry which every science makes into the proof of any given assertion. Every partial demonstration, we may say, makes assumptions, some avowed, others implied. The theory of knowledge endeavours to analyse the first sort, expose the second, and test both. While, lastly, its operations are, of course, not confined to any class of judgments, but should apply, ideally, to all our knowledge and belief. That is, it aims at giving the broad, fundamental conditions on which our knowledge and belief in general are founded; the application of these conditions belonging, of course, to special inquiries.

With the content of knowledge we deal in a still more limited sense. To discuss everything literally implied by the words would be to write a treatise de omnibus rebus. But logic has to trace the question, “What do we know?” so far as it is dependent on, or in turn illustrative of, the question, How we know? To take an instance, the question of the knowledge of an external material world—a question of what we know—was no sooner propounded than it raised in its deepest form the question how we know anything at all. It is obvious that any satisfactory theory of the conditions of knowledge must explain the knowledge that we have, and it follows that the main types of this knowledge must be analysed and understood before we know what we have to explain. If, however, the main divisions of our knowledge are made clear, and if it is seen that the conditions which we have assumed are sufficient to account for them, it will not be presumptuous to suppose that the detail of each division is to be explained by the play of the same conditions on different material. If we can explain, say, our knowledge of cause and effect in the abstract, there will be little difficulty in admitting that the same conditions in varying circumstances will give us our detailed knowledge of concrete effects and their causes. The question of the content of knowledge, then, only enters into logic in a broad and general sense. We must endeavour to find the summa genera of reality, and show that the conditions which we postulate explain our knowledge of them all. The detail of the various genera will not trouble us further.

But at this point the question may be raised, whether all that claims to be knowledge is really such. It may be said that we are not bound to lay down such conditions as will explain every kind of “knowledge,” for much that is called knowledge by the “ordinary” consciousness ceases to be such for the philosopher who analyses it. We have come, in fact, to our third question, which is logically anterior to that of the conditions of knowledge—the question, namely, of validity. Valid knowledge and illusion, however, have this much in common, that both of them consist of assertions, and the most illusory assertion is a fact to be explained just as much as the most scientific knowledge. Knowledge or correct assertion, moreover, is assertion made under certain differentiating conditions which it is the business of logic to discover; and hence we have, in fact, to deal with a wider genus of which “knowledge” is a part only. The conditions of assertion in general, and of good or true assertion in particular, are the subject of our treatise, but the greatest of these is true assertion. And we shall deal with assertion at large only so far as it will aid us in determining the conditions of true assertion, or knowledge. Understanding knowledge, then, in its strict sense in which truth or validity are included, we may say that our purpose is to examine the conditions and contents of knowledge in their broadest aspect.

The emphasis laid on validity is a characteristic which tends to distinguish the logical from the psychological treatment of the intellect. To psychology every mental state is of interest simply as a mental state; and if as psychologists we are investigating a belief, our main point would be to determine, not whether it is right or wrong, but how it came about, or of what mental stuff (so to say) it is made; whether it is allied to the volitional or emotional side of our nature, whether it is accompanied by a constriction of the small arteries or a tension of the muscles of the scalp, or a rise of blood pressure, how many thousandths of a second it takes to form, to what associations it will give rise, or any other question which the wit of man, or of an experimental psychologist, may suggest. But if we are logicians these questions are of value only if they suggest answers to the further questions—is this belief true or false; does it correspond to fact or not? In short, we have to deal with knowledge, that is, the relation of belief to fact; we consider the mind “non tantum in facilitate propria sed quatenus copulatur cum rebus” I do not wish to draw an academic distinction between logic and psychology. I mean for my own part to draw on psychological results whenever convenient. Distinctions between the sciences should, to quote Bacon again, be taken for lines and veins rather than for sections and separations. And the real meaning of the strong line of separation within which Metaphysics has so often tried to entrench herself is simply, it is to be feared, that she did not wish to be embarrassed by any awkward psychological or physical fact. Seriously, it is nonsense to speak of a thing being true for psychology but false for metaphysics. If truth is anything it is one and the same for every method of investigation, and the phrase can at best be but a manner of speaking. All I remark, then, is that logic and psychology have different centres of interest, and that I shall make no further excuse for failing at several points to follow up questions of great psychological importance. I make no attempt to draw a line of demarcation between the two sciences, nor should I expect much result from any attempt to do so.

The data of logic we have seen to be the mass of thoughts, judgments, or, as we shall call them generically, assertions, which we actually find made or entertained by men. To explain these is to exhibit the conditions under which they arise; and though logic, as we have seen, is mainly concerned with the conditions under which their truth is assured, the two sets of conditions must (if there is such a thing as truth at all) tend often to coincide, and in one respect the method of determining them is the same. For in any case, the most hopeful way of trying to explain a mass of data, is to proceed by the hypothetical method. Start at any point you like and consider the conditions which seem to be involved in the assertion considered. Then take these conditions and apply them in other cases. In this way you first test the alleged conditions, and see whether they are fundamental factors in knowledge or mere results of a particular collocation of circumstances. And then, supposing them genuine, you see how far they will go. If you find some assertion which they will not explain there must be some residual condition which you must determine. If, on the other hand, you arrive at any point at a set of conditions, one or other or all of which appear to afford, in such general terms as you could reasonably expect, an explanation of any class of judgment which can be specified, then you would seem to have arrived at a true and even a complete account of the conditions of knowledge. I will give a simple and rough example. Take the judgment, “I saw him when I was in London three years ago”; ask its ground, and you are told it is memory. Now about memory two questions may be asked, Is it, first, an ultimate fact or factor in our mental economy, or can it be in turn resolved into simpler elements, or explained on a psychological basis? And, secondly, taking memory for whatever it may be worth, how far will it carry us? This must be tested by a second judgment, such as, “I think you will find him a very objectionable person.” Now, if we tried to explain this by memory too, the judgment would fall back into the less pretending one—“he certainly was so three years ago.” But he may have changed, and so between these two judgments there is a gulf fixed which memory alone cannot bridge, and which forces us to a further postulate. Our method then will be hypothetical, and, for the rest, we shall try to justify the use we make of it in our concluding chapters, when, well or ill, its work is done.

The method in question labours under one peculiar danger or difficulty of which notice should be given at the outset. In using it we are bound to deal with abstractions, with the anatomy of thought rather than with the living whole. We have to take thought to pieces and exhibit it in fragments, each of which by itself is never a true living thought, but only some side or aspect or function of mental activity. In doing this we are only carrying the work of thought itself a step further. For the whole process of the mind in dealing with reality involves abstractions and separations which constantly tend to emasculate the truth. The mind, with all its powers, is incapable of grasping the whole even of the “flower in the crannied wall.” It deals with it first under this aspect, and then under that—as a thing of beauty, as suggestive of a Wordsworthian sonnet, as injurious to the structure of the wall, as a Composita, as consisting mainly of carbon, oxygen, hydrogen, and nitrogen in certain proportions, as decomposing so many cubic feet of carbonic acid per diem under the influence of sunlight. And whichever aspect we like to take we are pretty sure to leave out the rest. The sonnet would be deranged by a thought of the carbonic acid. And yet somehow all these aspects belong to the flower. The whole, which is the real, contains or presents them all and many more. And so we learn our first lesson about thought, that to grasp anything at all we must leave out the greater part of it. We need not agree with Father Ogniben, that no man ever yet proclaimed a truth but he uttered twenty falsehoods to back it; but we must admit that the mind never yet sifted out a grain of truth without letting twenty other grains slip past unnoticed. And here is the danger of all thought—that it takes the fraction of reality which it has secured for itself as the whole, or as significant of the whole. The first of these assumptions is a downright mistake; the second is dangerous, and justified only by special conditions. All the onesidedness, the narrowness, and, above all, the intolerance of the world comes from this inevitable abstraction of thought. And so the mind, though it must abstract, limit, ignore, is bound always to supplement its partial dealings; it must “strive always towards the whole,” and if it cannot become the whole, it must try at least to understand its own limits.

Now, just as thought is abstract in its dealings with reality, so logic is abstract in its dealings with ordinary thought. Poor as thought is in comparison with the real, it is warm and living by the side of the bloodless (but necessary) formulse of the logician. The reason is just the same as before. Thought tries to grasp what of reality it can, but cannot grasp much. So it takes hold of a part, a fragment, and grips it tight, and fixes it before the mind, and names it, and consigns it to its pigeon-hole. It does that over and over again, and by this piecemeal process, in which much is always omitted at each stage, but the defects at one point are supplemented or corrected by what is done at another, the mind painfully carries on its reconstruction of reality in a form in which it becomes intelligible at length as a whole. Now logic does just the same thing with thought. It takes it in bits and it misses out much at each step, but it puts in corrections as it goes on, and so in piecemeal fashion it tries to reconstruct the world of thought for itself.

Thus logic uses words, clauses, sentences as symbols of thought. But any one of these taken in the isolated manner which logic can scarcely avoid is an abstraction, if not even a fiction. The word which is often thought of as representing an idea, clearly by itself represents nothing which can stand alone, unless it can be so much sound or so much ink. We shall have to notice this later, but I will point out here that even the sentence which is ordinarily supposed to stand for a complete thought is really an abstraction. You do not know what it really means unless you take it in its context. Everybody knows the use which can be made of quotations without their context; but if the question be pressed how much context ought to be given, it would be difficult often to draw the line short of the whole book, and even of the circumstances in which it is written. In many cases at least you can neither comprehend nor do justice to a man's utterance on a single point without knowing a good deal of general history in addition to that of the man himself. Take this sentence: “It is death to souls to become water.” Taken by itself this is mere talk, meaning nothing at all. Nor is it fully intelligible without a fairly exhaustive study of the fragments of Heraclitus in relation to all that we know of thought and science in the fifth and sixth centuries B.c. The doctrine then appears as the natural consequence of certain physical theories drawn with much acute-ness and imagination from the somewhat scanty data at the disposal of an early Greek philosopher. ¹

The single sentence is always more or less unintelligible when taken alone, i.e. apart not only from previous conversation but from the circumstances in which we are placed, the interest which we are understood to have in common, or the landscape which lies before us both. It is only an eccentric who, like “Mr. Fs Aunt,” plumps down remarks which bear no apparent relation to anything at all.

As with the sentence or the judgment, so with inference and all other processes of thought. We never assign the whole of the grounds on which we rest a result. What is more, we could not assign them if we tried. There are subtle indications, shreds and fibres of thought, complexities of relation in which each of our beliefs stands, which are all felt, which all have their effect, and which the most powerful and subtle mind could not unravel. No doubt one part of the advance of knowledge consists in becoming more explicit, so that we come to understand that which before we only knew; but this advance is very gradual, and perhaps its main effect hitherto has been to create some distrust of explicit reasoning as tending to half truths. We feel that there is more in our own reasonings than we ourselves know.

Our results, then, will at first be abstract in two ways. We shall have to take judgments and inferences more or less in isolation, that is, in abstraction from the other judgments and inferences with which they really stand in connection. And we shall have to deal with many functions or aspects of thought which may turn out, not to be real acts of thought at all, but rather to be involved as elements along with other elements in the structure of some real, concrete activity. In both cases we shall try to guard against errors which might arise from these limitations. It must be understood throughout that we are dealing piecemeal with a single structure. Each fragment that we take implies other fragments, and ultimately, we may say, the whole, just as the human hand implies the arm, and ultimately the whole structure of the body. But just as for certain purposes the hand may be studied alone so for certain purposes, and with good results up to a certain point, we may take any fragment of thought's work by itself, though ultimately to understand it all we shall be forced on to other fragments, and so little by little to some account of the whole.

Supposing our difficulties overcome, the results to be arrived at in the present work could not in any case figure as a system of philosophy. It is of some importance, with a view to understanding the real aim and scope of the theory of knowledge, to make as clear as possible the part which it plays in philosophy as a whole. We must first, therefore, get some notion of what we, for our part, mean by philosophy. Philosophy, like any special science, is, or aims at becoming, a body of connected, systematic, reasoned truth. Now every science has its own appropriate subject-matter marked out more or less clearly from other things. Quantity, space, the general attributes of matter, the specific characters of different substances form the basis of mathematics, physics, and chemistry. But every science must, as we have seen, deal with abstractions, and limit its view to one side of reality. The aim of philosophy is ultimately to make good the deficiency by taking some view over reality at large. Keality as a whole is the subject of philosophy, and no fact is too poor or too remote to come within its range. This view is caricatured when the philosopher is taken to be a kind of Professor of Things-in-General. In reality, as Comte pointed out, he is as much a specialist as anybody else. No one claims for the philosopher that he can know physics like a physicist, and geometry like a mathematician. His speciality consists of the principles and results of other specialities, and it is enough for him—and difficulty enough too—if he can master these sufficiently for his purpose, The true philosophy, then, would be the synthesis of all that is known and, perhaps we should add, of much also that is only felt or hoped. Confining ourselves for the present to “what is known,” it is clear that we should range ourselves with those who look on philosophy as essentially a synthesis of the sciences. Now, to this synthesis the theory of knowledge contributes only one element. It is not, that is to say, a theory of reality or a theory of all that is known. It is a theory only of the conditions of genuine knowledge and of certain broad aspects of the results or tendencies of knowledge which seem to be bound up with any just conception of its conditions. Of course this is, in a way, a theory of reality; ¹ and of course, in a way, any theory that professed to be a theory of anything, must claim to deal with reality. But by a theory of reality I should understand an attempt to deal with the real world as a whole, not merely with those elementary presuppositions as to its nature which seem to be involved in our knowing it at all.