As there cannot be said to be a beaten path in philosophy, and as "Introductions" to the subject differ widely from one another, it is proper that I should give an indication of the scope of the present volume.
1. To point out what the word "philosophy" is made to cover in our universities and colleges at the present day, and to show why it is given this meaning.
2. To explain the nature of reflective or philosophical thinking, and to show how it differs from common thought and from science.
3. To give a general view of the main problems with which philosophers have felt called upon to deal.
4. To give an account of some of the more important types of philosophical doctrine which have arisen out of the consideration of such problems.
5. To indicate the relation of philosophy to the so-called philosophical sciences, and to the other sciences.
6. To show, finally, that the study of philosophy is of value to us all, and to give some practical admonitions on spirit and method. Had these admonitions been impressed upon me at a time when I was in especial need of guidance, I feel that they would have spared me no little anxiety and confusion of mind. For this reason, I recommend them to the attention of the reader.
Such is the scope of my book. It aims to tell what philosophy is. It is not its chief object to advocate a particular type of doctrine. At the same time, as it is impossible to treat of the problems of philosophy except from some point of view, it will be found that, in Chapters III to XI, a doctrine is presented. It is the same as that presented much more in detail, and with a greater wealth of reference, in my "System of Metaphysics," which was published a short time ago. In the Notes in the back of this volume, the reader will find references to those parts of the larger work which treat of the subjects more briefly discussed here. It will be helpful to the teacher to keep the larger work on hand, and to use more or less of the material there presented as his undergraduate classes discuss the chapters of this one. Other references are also given in the Notes, and it may be profitable to direct the attention of students to them.
The present book has been made as clear and simple as possible, that no unnecessary difficulties may be placed in the path of those who enter upon the thorny road of philosophical reflection. The subjects treated are deep enough to demand the serious attention of any one; and they are subjects of fascinating interest. That they are treated simply and clearly does not mean that they are treated superficially. Indeed, when a doctrine is presented in outline and in a brief and simple statement, its meaning may be more readily apparent than when it is treated more exhaustively. For this reason, I especially recommend, even to those who are well acquainted with philosophy, the account of the external world contained in Chapter IV.
For the doctrine I advocate I am inclined to ask especial consideration on the ground that it is, on the whole, a justification of the attitude taken by the plain man toward the world in which he finds himself. The experience of the race is not a thing that we may treat lightly.
Thus, it is maintained that there is a real external world presented in our experience—not a world which we have a right to regard as the sensations or ideas of any mind. It is maintained that we have evidence that there are minds in certain relations to that world, and that we can, within certain limits, determine these relations. It is pointed out that the plain man's belief in the activity of his mind and his notion of the significance of purposes and ends are not without justification. It is indicated that theism is a reasonable doctrine, and it is held that the human will is free in the only proper sense of the word "freedom." Throughout it is taken for granted that the philosopher has no private system of weights and measures, but must reason as other men reason, and must prove his conclusions in the same sober way.
I have written in hopes that the book may be of use to undergraduate students. They are often repelled by philosophy, and I cannot but think that this is in part due to the dry and abstract form in which philosophers have too often seen fit to express their thoughts. The same thoughts can be set forth in plain language, and their significance illustrated by a constant reference to experiences which we all have—experiences which must serve as the foundation to every theory of the mind and the world worthy of serious consideration.
But there are many persons who cannot attend formal courses of instruction, and who, nevertheless, are interested in philosophy. These, also, I have had in mind; and I have tried to be so clear that they could read the work with profit in the absence of a teacher.
Lastly, I invite the more learned, if they have found my "System of Metaphysics" difficult to understand in any part, to follow the simple statement contained in the chapters above alluded to, and then to return, if they will, to the more bulky volume.
GEORGE STUART FULLERTON.
THE MEANING OF THE WORD "PHILOSOPHY" IN THE PAST AND IN THE PRESENT.
I must warn the reader at the outset that the title of this chapter seems to promise a great deal more than he will find carried out in the chapter itself. To tell all that philosophy has meant in the past, and all that it means to various classes of men in the present, would be a task of no small magnitude, and one quite beyond the scope of such a volume as this. But it is not impossible to give within small compass a brief indication, at least, of what the word once signified, to show how its signification has undergone changes, and to point out to what sort of a discipline or group of disciplines educated men are apt to apply the word, notwithstanding their differences of opinion as to the truth or falsity of this or that particular doctrine. Why certain subjects of investigation have come to be grouped together and to be regarded as falling within the province of the philosopher, rather than certain other subjects, will, I hope, be made clear in the body of the work. Only an indication can be given in this chapter.
1. THE BEGINNINGS OF PHILOSOPHY.—The Greek historian Herodotus (484-424 B.C.) appears to have been the first to use the verb "to philosophize." He makes Croesus tell Solon how he has heard that he "from a desire of knowledge has, philosophizing, journeyed through many lands." The word "philosophizing" seems to indicate that Solon pursued knowledge for its own sake, and was what we call an investigator. As for the word "philosopher" (etymologically, a lover of wisdom), a certain somewhat unreliable tradition traces it back to Pythagoras (about 582-500 B.C.). As told by Cicero, the story is that, in a conversation with Leon, the ruler of Phlius, in the Peloponnesus, he described himself as a philosopher, and said that his business was an investigation into the nature of things.
At any rate, both the words "philosopher" and "philosophy" are freely used in the writings of the disciples of Socrates (470-399 B.C.), and it is possible that he was the first to make use of them. The seeming modesty of the title philosopher—for etymologically it is a modest one, though it has managed to gather a very different signification with the lapse of time—the modesty of the title would naturally appeal to a man who claimed so much ignorance, as Socrates; and Plato represents him as distinguishing between the lover of wisdom and the wise, on the ground that God alone may be called wise. From that date to this the word "philosopher" has remained with us, and it has meant many things to many men. But for centuries the philosopher has not been simply the investigator, nor has he been simply the lover of wisdom.
An investigation into the origin of words, however interesting in itself, can tell us little of the uses to which words are put after they have come into being. If we turn from etymology to history, and review the labors of the men whom the world has agreed to call philosophers, we are struck by the fact that those who head the list chronologically appear to have been occupied with crude physical speculations, with attempts to guess what the world is made out of, rather than with that somewhat vague something that we call philosophy to-day.
Students of the history of philosophy usually begin their studies with the speculations of the Greek philosopher Thales (b. 624 B.C.). We are told that he assumed water to be the universal principle out of which all things are made, and that he maintained that "all things are full of gods." We find that Anaximander, the next in the list, assumed as the source out of which all things proceed and that to which they all return "the infinite and indeterminate"; and that Anaximenes, who was perhaps his pupil, took as his principle the all-embracing air.
This trio constitutes the Ionian school of philosophy, the earliest of the Greek schools; and one who reads for the first time the few vague statements which seem to constitute the sum of their contributions to human knowledge is impelled to wonder that so much has been made of the men.
This wonder disappears, however, when one realizes that the appearance of these thinkers was really a momentous thing. For these men turned their faces away from the poetical and mythologic way of accounting for things, which had obtained up to their time, and set their faces toward Science. Aristotle shows us how Thales may have been led to the formulation of his main thesis by an observation of the phenomena of nature. Anaximander saw in the world in which he lived the result of a process of evolution. Anaximenes explains the coming into being of fire, wind, clouds, water, and earth, as due to a condensation and expansion of the universal principle, air. The boldness of their speculations we may explain as due to a courage born of ignorance, but the explanations they offer are scientific in spirit, at least.
Moreover, these men do not stand alone. They are the advance guard of an army whose latest representatives are the men who are enlightening the world at the present day. The evolution of science—taking that word in the broad sense to mean organized and systematized knowledge—must be traced in the works of the Greek philosophers from Thales down. Here we have the source and the rivulet to which we can trace back the mighty stream which is flowing past our own doors. Apparently insignificant in its beginnings, it must still for a while seem insignificant to the man who follows with an unreflective eye the course of the current.
It would take me too far afield to give an account of the Greek schools which immediately succeeded the Ionic: to tell of the Pythagoreans, who held that all things were constituted by numbers; of the Eleatics, who held that "only Being is," and denied the possibility of change, thereby reducing the shifting panorama of the things about us to a mere delusive world of appearances; of Heraclitus, who was so impressed by the constant flux of things that he summed up his view of nature in the words: "Everything flows"; of Empedocles, who found his explanation of the world in the combination of the four elements, since become traditional, earth, water, fire, and air; of Democritus, who developed a materialistic atomism which reminds one strongly of the doctrine of atoms as it has appeared in modern science; of Anaxagoras, who traced the system of things to the setting in order of an infinite multiplicity of different elements,—"seeds of things,"—which setting in order was due to the activity of the finest of things, Mind.
It is a delight to discover the illuminating thoughts which came to the minds of these men; and, on the other hand, it is amusing to see how recklessly they launched themselves on boundless seas when they were unprovided with chart and compass. They were like brilliant children, who know little of the dangers of the great world, but are ready to undertake anything. These philosophers regarded all knowledge as their province, and did not despair of governing so great a realm. They were ready to explain the whole world and everything in it. Of course, this can only mean that they had little conception of how much there is to explain, and of what is meant by scientific explanation.
It is characteristic of this series of philosophers that their attention was directed very largely upon the external world. It was natural that this should be so. Both in the history of the race and in that of the individual, we find that the attention is seized first by material things, and that it is long before a clear conception of the mind and of its knowledge is arrived at. Observation precedes reflection. When we come to think definitely about the mind, we are all apt to make use of notions which we have derived from our experience of external things. The very words we use to denote mental operations are in many instances taken from this outer realm. We "direct" the attention; we speak of "apprehension," of "conception," of "intuition." Our knowledge is "clear" or "obscure"; an oration is "brilliant"; an emotion is "sweet" or "bitter." What wonder that, as we read over the fragments that have come down to us from the Pre-Socratic philosophers, we should be struck by the fact that they sometimes leave out altogether and sometimes touch lightly upon a number of those things that we regard to-day as peculiarly within the province of the philosopher. They busied themselves with the world as they saw it, and certain things had hardly as yet come definitely within their horizon.
2. THE GREEK PHILOSOPHY AT ITS HEIGHT.—The next succeeding period sees certain classes of questions emerge into prominence which had attracted comparatively little attention from the men of an earlier day. Democritus of Abdera, to whom reference has been made above, belongs chronologically to this latter period, but his way of thinking makes us class him with the earlier philosophers. It was characteristic of these latter that they assumed rather naïvely that man can look upon the world and can know it, and can by thinking about it succeed in giving a reasonable account of it. That there may be a difference between the world as it really is and the world as it appears to man, and that it may be impossible for man to attain to a knowledge of the absolute truth of things, does not seem to have occurred to them.
The fifth century before Christ was, in Greece, a time of intense intellectual ferment. One is reminded, in reading of it, of the splendid years of the Renaissance in Italy, of the awakening of the human mind to a vigorous life which cast off the bonds of tradition and insisted upon the right of free and unfettered development. Athens was the center of this intellectual activity.
In this century arose the Sophists, public teachers who busied themselves with all departments of human knowledge, but seemed to lay no little emphasis upon certain questions that touched very nearly the life of man. Can man attain to truth at all—to a truth that is more than a mere truth to him, a seeming truth? Whence do the laws derive their authority? Is there such a thing as justice, as right? It was with such questions as these that the Sophists occupied themselves, and such questions as these have held the attention of mankind ever since. When they make their appearance in the life of a people or of an individual man, it means that there has been a rebirth, a birth into the life of reflection.
When Socrates, that greatest of teachers, felt called upon to refute the arguments of these men, he met them, so to speak, on their own ground, recognizing that the subjects of which they discoursed were, indeed, matter for scientific investigation. His attitude seemed to many conservative persons in his day a dangerous one; he was regarded as an innovator; he taught men to think and to raise questions where, before, the traditions of the fathers had seemed a sufficient guide to men's actions.
And, indeed, he could not do otherwise. Men had learned to reflect, and there had come into existence at least the beginnings of what we now sometimes rather loosely call the mental and moral sciences. In the works of Socrates' disciple Plato (428-347 B.C.) and in those of Plato's disciple Aristotle (384-322 B.C.), abundant justice is done to these fields of human activity. These two, the greatest among the Greek philosophers, differ from each other in many things, but it is worthy of remark that they both seem to regard the whole sphere of human knowledge as their province.
Plato is much more interested in the moral sciences than in the physical, but he, nevertheless, feels called upon to give an account of how the world was made and out of what sort of elements. He evidently does not take his own account very seriously, and recognizes that he is on uncertain ground. But he does not consider the matter beyond his jurisdiction.
As for Aristotle, that wonderful man seems to have found it possible to represent worthily every science known to his time, and to have marked out several new fields for his successors to cultivate. His philosophy covers physics, cosmology, zoölogy, logic, metaphysics, ethics, psychology, politics and economics, rhetoric and poetics.
Thus we see that the task of the philosopher was much the same at the period of the highest development of the Greek philosophy that it had been earlier. He was supposed to give an account of the system of things. But the notion of what it means to give an account of the system of things had necessarily undergone some change. The philosopher had to be something more than a natural philosopher.
3. PHILOSOPHY AS A GUIDE TO LIFE.—At the close of the fourth century before Christ there arose the schools of the Stoics, the Epicureans, and the Skeptics. In them we seem to find a somewhat new conception of philosophy—philosophy appears as chiefly a guide to life. The Stoic emphasizes the necessity of living "according to nature," and dwells upon the character of the wise man; the Epicurean furnishes certain selfish maxims for getting through life as pleasantly as possible; the Skeptic counsels apathy, an indifference to all things,—blessed is he who expects nothing, for he shall not be disappointed.
And yet, when we examine more closely these systems, we find a conception of philosophy not really so very different from that which had obtained before. We do not find, it is true, that disinterested passion for the attainment of truth which is the glory of science. Man seems quite too much concerned with the problem of his own happiness or unhappiness; he has grown morbid. Nevertheless, the practical maxims which obtain in each of these systems are based upon a certain view of the system of things as a whole.
The Stoic tells us of what the world consists; what was the beginning and what will be the end of things; what is the relation of the system of things to God. He develops a physics and a logic as well as a system of ethics. The Epicurean informs us that the world originated in a rain of atoms through space; he examines into the foundations of human knowledge; and he proceeds to make himself comfortable in a world from which he has removed those disturbing elements, the gods. The Skeptic decides that there is no such thing as truth, before he enunciates the dogma that it is not worth while to worry about anything. The philosophy of each school includes a view of the system of things as a whole. The philosopher still regarded the universe of knowledge as his province.
4. PHILOSOPHY IN THE MIDDLE AGES.—I cannot do more than mention Neo-Platonism, that half Greek and half Oriental system of doctrine which arose in the third century after Christ, the first system of importance after the schools mentioned above. But I must not pass it by without pointing out that the Neo-Platonic philosopher undertook to give an account of the origin, development, and end of the whole system of things.
In the Middle Ages there gradually grew up rather a sharp distinction between those things that can be known through the unaided reason and those things that can only be known through a supernatural revelation. The term "philosophy" came to be synonymous with knowledge attained by the natural light of reason. This seems to imply some sort of a limitation to the task of the philosopher. Philosophy is not synonymous with all knowledge.
But we must not forget to take note of the fact that philosophy, even with this limitation, constitutes a pretty wide field. It covers both the physical and the moral sciences. Nor should we omit to notice that the scholastic philosopher was at the same time a theologian. Albert the Great and St. Thomas Aquinas, the famous scholastics of the thirteenth century, had to write a "Summa Theologiae," or system of theology, as well as to treat of the other departments of human knowledge.
Why were these men not overwhelmed with the task set them by the tradition of their time? It was because the task was not, after all, so great as a modern man might conceive it to be. Gil Blas, in Le Sage's famous romance, finds it possible to become a skilled physician in the twinkling of an eye, when Dr. Sangrado has imparted to him the secret that the remedy for all diseases is to be found in bleeding the patient and in making him drink copiously of hot water. When little is known about things, it does not seem impossible for one man to learn that little. During the Middle Ages and the centuries preceding, the physical sciences had a long sleep. Men were much more concerned in the thirteenth century to find out what Aristotle had said than they were to address questions to nature. The special sciences, as we now know them, had not been called into existence.
5. THE MODERN PHILOSOPHY.—The submission of men's minds to the authority of Aristotle and of the church gradually gave way. A revival of learning set in. Men turned first of all to a more independent choice of authorities, and then rose to the conception of a philosophy independent of authority, of a science based upon an observation of nature, of a science at first hand. The special sciences came into being.
But the old tradition of philosophy as universal knowledge remained. If we pass over the men of the transition period and turn our attention to Francis Bacon (1561-1626) and Rene Descartes (1596-1650), the two who are commonly regarded as heading the list of the modern philosophers, we find both of them assigning to the philosopher an almost unlimited field.
Bacon holds that philosophy has for its objects God, man, and nature, and he regards it as within his province to treat of "philosophia prima" (a sort of metaphysics, though he does not call it by this name), of logic, of physics and astronomy, of anthropology, in which he includes psychology, of ethics, and of politics. In short, he attempts to map out the whole field of human knowledge, and to tell those who work in this corner of it or in that how they should set about their task.
As for Descartes, he writes of the trustworthiness of human knowledge, of the existence of God, of the existence of an external world, of the human soul and its nature, of mathematics, physics, cosmology, physiology, and, in short, of nearly everything discussed by the men of his day. No man can accuse this extraordinary Frenchman of a lack of appreciation of the special sciences which were growing up. No one in his time had a better right to be called a scientist in the modern sense of the term. But it was not enough for him to be a mere mathematician, or even a worker in the physical sciences generally. He must be all that has been mentioned above.
The conception of philosophy as of a something that embraces all departments of human knowledge has not wholly passed away even in our day. I shall not dwell upon Spinoza (1632-1677), who believed it possible to deduce a world a priori with mathematical precision; upon Christian Wolff (1679-1754), who defined philosophy as the knowledge of the causes of what is or comes into being; upon Fichte (1762-1814), who believed that the philosopher, by mere thinking, could lay down the laws of all possible future experience; upon Schelling (1775-1854), who, without knowing anything worth mentioning about natural science, had the courage to develop a system of natural philosophy, and to condemn such investigators as Boyle and Newton; upon Hegel (1770-1831), who undertakes to construct the whole system of reality out of concepts, and who, with his immediate predecessors, brought philosophy for a while into more or less disrepute with men of a scientific turn of mind. I shall come down quite to our own times, and consider a man whose conception of philosophy has had and still has a good deal of influence, especially with the general public—with those to whom philosophy is a thing to be taken up in moments of leisure, and cannot be the serious pursuit of a life.
"Knowledge of the lowest kind," says Herbert Spencer, "is un-unified knowledge; Science is partially-unified knowledge; Philosophy is completely-unified knowledge."  Science, he argues, means merely the family of the Sciences—stands for nothing more than the sum of knowledge formed of their contributions. Philosophy is the fusion of these contributions into a whole; it is knowledge of the greatest generality. In harmony with this notion Spencer produced a system of philosophy which includes the following: A volume entitled "First Principles," which undertakes to show what man can and what man cannot know; a treatise on the principles of biology; another on the principles of psychology; still another on the principles of sociology; and finally one on the principles of morality. To complete the scheme it would have been necessary to give an account of inorganic nature before going on to the phenomena of life, but our philosopher found the task too great and left this out.
Now, Spencer was a man of genius, and one finds in his works many illuminating thoughts. But it is worthy of remark that those who praise his work in this or in that field are almost always men who have themselves worked in some other field and have an imperfect acquaintance with the particular field that they happen to be praising. The metaphysician finds the reasonings of the "First Principles" rather loose and inconclusive; the biologist pays little heed to the "Principles of Biology"; the sociologist finds Spencer not particularly accurate or careful in the field of his predilection. He has tried to be a professor of all the sciences, and it is too late in the world's history for him or for any man to cope with such a task. In the days of Plato a man might have hoped to accomplish it.
6. WHAT PHILOSOPHY MEANS IN OUR TIME.—It savors of temerity to write down such a title as that which heads the present section. There are men living to-day to whom philosophy means little else than the doctrine of Kant, or of Hegel, or of the brothers Caird, or of Herbert Spencer, or even of St. Thomas Aquinas, for we must not forget that many of the seminaries of learning in Europe and some in America still hold to the mediaeval church philosophy.
But let me gather up in a few words the purport of what has been said above. Philosophy once meant the whole body of scientific knowledge. Afterward it came to mean the whole body of knowledge which could be attained by the mere light of human reason, unaided by revelation. The several special sciences sprang up, and a multitude of men have for a long time past devoted themselves to definite limited fields of investigation with little attention to what has been done in other fields. Nevertheless, there has persisted the notion of a discipline which somehow concerns itself with the whole system of things, rather than with any limited division of that broad field. It is a notion not peculiar to the disciples of Spencer. There are many to whom philosophy is a "Weltweisheit," a world-wisdom. Shall we say that this is the meaning of the word philosophy now? And if we do, how shall we draw a line between philosophy and the body of the special sciences?
Perhaps the most just way to get a preliminary idea of what philosophy means to the men of our time is to turn away for the time being from the definition of any one man or group of men, and to ask ourselves what a professor of philosophy in an American or European university is actually supposed to teach.
It is quite clear that he is not supposed to be an Aristotle. He does not represent all the sciences, and no one expects him to lecture on mathematics, mechanics, physics, chemistry, zoölogy, botany, economics, politics, and various other disciplines. There was a time when he might have been expected to teach all that men could know, but that time is long past.
Nevertheless, there is quite a group of sciences which are regarded as belonging especially to his province; and although a man may devote a large part of his attention to some one portion of the field, he would certainly be thought remiss if he wholly neglected the rest. This group of sciences includes logic, psychology, ethics and aesthetics, metaphysics, and the history of philosophy. I have not included epistemology or the "theory of knowledge" as a separate discipline, for reasons which will appear later (Chapter XIX); and I have included the history of philosophy, because, whether we care to call this a special science or not, it constitutes a very important part of the work of the teacher of philosophy in our day.
Of this group of subjects the student who goes to the university to study philosophy is supposed to know something before he leaves its walls, whatever else he may or may not know.
It should be remarked, again, that there is commonly supposed to be a peculiarly close relation between philosophy and religion. Certainly, if any one about a university undertakes to give a course of lectures on theism, it is much more apt to be the professor of philosophy than the professor of mathematics or of chemistry. The man who has written an "Introduction to Philosophy," a "Psychology," a "Logic," and an "Outlines of Metaphysics" is very apt to regard it as his duty to add to the list a "Philosophy of Religion." The students in the theological seminaries of Europe and America are usually encouraged, if not compelled, to attend courses in philosophy.
Finally, it appears to be definitely accepted that even the disciplines that we never think of classing among the philosophical sciences are not wholly cut off from a connection with philosophy. When we are occupied, not with adding to the stock of knowledge embraced within the sphere of any special science, but with an examination of the methods of the science, with, so to speak, a criticism of the foundations upon which the science rests, our work is generally recognized as philosophical. It strikes no one as odd in our day that there should be established a "Journal of Philosophy, Psychology, and Scientific Methods," but we should think it strange if some one announced the intention to publish a "Journal of Philosophy and Comparative Anatomy." It is not without its significance that, when Mach, who had been professor of physics at Prague, was called (in 1895) to the University of Vienna to lecture on the history and theory of the inductive sciences, he was made, not professor of physics, but professor of philosophy.
The case, then, stands thus: a certain group of disciplines is regarded as falling peculiarly within the province of the professor of philosophy, and the sciences which constitute it are frequently called the philosophical sciences; moreover, it is regarded as quite proper that the teacher of philosophy should concern himself with the problems of religion, and should pry into the methods and fundamental assumptions of special sciences in all of which it is impossible that he should be an adept. The question naturally arises: Why has his task come to be circumscribed as it is? Why should he teach just these things and no others?
To this question certain persons are at once ready to give an answer. There was a time, they argue, when it seemed possible for one man to embrace the whole field of human knowledge. But human knowledge grew; the special sciences were born; each concerned itself with a definite class of facts and developed its own methods. It became possible and necessary for a man to be, not a scientist at large, but a chemist, a physicist, a biologist, an economist. But in certain portions of the great field men have met with peculiar difficulties; here it cannot be said that we have sciences, but rather that we have attempts at science. The philosopher is the man to whom is committed what is left when we have taken away what has been definitely established or is undergoing investigation according to approved scientific methods. He is Lord of the Uncleared Ground, and may wander through it in his compassless, irresponsible way, never feeling that he is lost, for he has never had any definite bearings to lose.
Those who argue in this way support their case by pointing to the lack of a general consensus of opinion which obtains in many parts of the field which the philosopher regards as his own; and also by pointing out that, even within this field, there is a growing tendency on the part of certain sciences to separate themselves from philosophy and become independent. Thus the psychologist and the logician are sometimes very anxious to have it understood that they belong among the scientists and not among the philosophers.
Now, this answer to the question that we have raised undoubtedly contains some truth. As we have seen from the sketch contained in the preceding pages, the word philosophy was once a synonym for the whole sum of the sciences or what stood for such; gradually the several sciences have become independent and the field of the philosopher has been circumscribed. We must admit, moreover, that there is to be found in a number of the special sciences a body of accepted facts which is without its analogue in philosophy. In much of his work the philosopher certainly seems to be walking upon more uncertain ground than his neighbors; and if he is unaware of that fact, it must be either because he has not a very nice sense of what constitutes scientific evidence, or because he is carried away by his enthusiasm for some particular form of doctrine.
Nevertheless, it is just to maintain that the answer we are discussing is not a satisfactory one. For one thing, we find in it no indication of the reason why the particular group of disciplines with which the philosopher occupies himself has been left to him, when so many sciences have announced their independence. Why have not these, also, separated off and set up for themselves? Is it more difficult to work in these fields than in others? and, if so, what reason can be assigned for the fact?
Take psychology as an instance. How does it happen that the physicist calmly develops his doctrine without finding it necessary to make his bow to philosophy at all, while the psychologist is at pains to explain that his book is to treat psychology as "a natural science," and will avoid metaphysics as much as possible? For centuries men have been interested in the phenomena of the human mind. Can anything be more open to observation than what passes in a man's own consciousness? Why, then, should the science of psychology lag behind? and why these endless disputes as to whether it can really be treated as a "natural science" at all?
Again. May we assume that, because certain disciplines have taken a position of relative independence, therefore all the rest of the field will surely come to be divided up in the same way, and that there will be many special sciences, but no such thing as philosophy? It is hasty to assume this on no better evidence than that which has so far been presented. Before making up one's mind upon this point, one should take a careful look at the problems with which the philosopher occupies himself.
A complete answer to the questions raised above can only be given in the course of the book, where the main problems of philosophy are discussed, and the several philosophical sciences are taken up and examined. But I may say, in anticipation, as much as this:
(1) Philosophy is reflective knowledge. What is meant by reflective knowledge will be explained at length in the next chapter.
(2) The sciences which are grouped together as philosophical are those in which we are forced back upon the problems of reflective thought, and cannot simply put them aside.
(3) The peculiar difficulties of reflective thought may account for the fact that these sciences are, more than others, a field in which we may expect to find disputes and differences of opinion.
(4) We need not be afraid that the whole field of human knowledge will come to be so divided up into special sciences that philosophy will disappear. The problems with which the philosopher occupies himself are real problems, which present themselves unavoidably to the thoughtful mind, and it is not convenient to divide these up among the several sciences. This will become clearer as we proceed.
 "First Principles," Part II, section 37.
COMMON THOUGHT, SCIENCE, AND REFLECTIVE THOUGHT.
7. COMMON THOUGHT.—Those who have given little attention to the study of the human mind are apt to suppose that, when the infant opens its eyes upon the new world of objects surrounding its small body, it sees things much as they do themselves. They are ready to admit that it does not know much about things, but it strikes them as absurd for any one to go so far as to say that it does not see things—the things out there in space before its eyes.
Nevertheless, the psychologist tells us that it requires quite a course of education to enable us to see things—not to have vague and unmeaning sensations, but to see things, things that are known to be touchable as well as seeable, things that are recognized as having size and shape and position in space. And he aims a still severer blow at our respect for the infant when he goes on to inform us that the little creature is as ignorant of itself as it is of things; that in its small world of as yet unorganized experiences there is no self that is distinguished from other things; that it may cry vociferously without knowing who is uncomfortable, and may stop its noise without knowing who has been taken up into the nurse's arms and has experienced an agreeable change.
This chaotic little world of the dawning life is not our world, the world of common thought, the world in which we all live and move in maturer years; nor can we go back to it on the wings of memory. We seem to ourselves to have always lived in a world of things,—things in time and space, material things. Among these things there is one of peculiar interest, and which we have not placed upon a par with the rest, our own body, which sees, tastes, touches, other things. We cannot remember a time when we did not know that with this body are somehow bound up many experiences which interest us acutely; for example, experiences of pleasure and pain. Moreover, we seem always to have known that certain of the bodies which surround our own rather resemble our own, and are in important particulars to be distinguished from the general mass of bodies.
Thus, we seem always to have been living in a world of things and to have recognized in that world the existence of ourselves and of other people. When we now think of "ourselves" and of "other people," we think of each of the objects referred to as possessing a mind. May we say that, as far back as we can remember, we have thought of ourselves and of other persons as possessing minds?
Hardly. The young child does not seem to distinguish between mind and body, and, in the vague and fragmentary pictures which come back to us from our early life, certainly this distinction does not stand out. The child may be the completest of egoists, it may be absorbed in itself and all that directly concerns this particular self, and yet it may make no conscious distinction between a bodily self and a mental, between mind and body. It does not explicitly recognize its world as a world that contains minds as well as bodies.
But, however it may be with the child in the earlier stages of its development, we must all admit that the mature man does consciously recognize that the world in which he finds himself is a world that contains minds as well as bodies. It never occurs to him to doubt that there are bodies, and it never occurs to him to doubt that there are minds.
Does he not perceive that he has a body and a mind? Has he not abundant evidence that his mind is intimately related to his body? When he shuts his eyes, he no longer sees, and when he stops his ears, he no longer hears; when his body is bruised, he feels pain; when he wills to raise his hand, his body carries out the mental decree. Other men act very much as he does; they walk and they talk, they laugh and they cry, they work and they play, just as he does. In short, they act precisely as though they had minds like his own. What more natural than to assume that, as he himself gives expression, by the actions of his body, to the thoughts and emotions in his mind, so his neighbor does the same?
We must not allow ourselves to underrate the plain man's knowledge either of bodies or of minds. It seems, when one reflects upon it, a sufficiently wonderful thing that a few fragmentary sensations should automatically receive an interpretation which conjures up before the mind a world of real things; that, for example, the little patch of color sensation which I experience when I turn my eyes toward the window should seem to introduce me at once to a world of material objects lying in space, clearly defined in magnitude, distance, and direction; that an experience no more complex should be the key which should unlock for me the secret storehouse of another mind, and lay before me a wealth of thoughts and emotions not my own. From the poor, bare, meaningless world of the dawning intelligence to the world of common thought, a world in which real things with their manifold properties, things material and things mental, bear their part, is indeed a long step.
And we should never forget that he who would go farther, he who would strive to gain a better knowledge of matter and of mind by the aid of science and of philosophical reflection, must begin his labors on this foundation which is common to us all. How else can he begin than by accepting and more critically examining the world as it seems revealed in the experience of the race?
8. SCIENTIFIC KNOWLEDGE.—Still, the knowledge of the world which we have been discussing is rather indefinite, inaccurate, and unsystematic. It is a sufficient guide for common life, but its deficiencies may be made apparent. He who wishes to know matter and mind better cannot afford to neglect the sciences.
Now, it is important to observe that although, when the plain man grows scientific, great changes take place in his knowledge of things, yet his way of looking at the mind and the world remains in general much what it was before. To prevent this statement from being misunderstood, I must explain it at some length.
Let us suppose that the man in question takes up the study of botany. Need he do anything very different from what is done more imperfectly by every intelligent man who interests himself in plants? There in the real material world before him are the same plants that he observed somewhat carelessly before. He must collect his information more systematically and must arrange it more critically, but his task is not so much to do something different as it is to do the same thing much better.
The same is evidently true of various other sciences, such as geology, zoölogy, physiology, sociology. Some men have much accurate information regarding rocks, animals, the functions of the bodily organs, the development of a given form of society, and other things of the sort, and other men have but little; and yet it is usually not difficult for the man who knows much to make the man who knows little understand, at least, what he is talking about. He is busying himself with things—the same things that interest the plain man, and of which the plain man knows something. He has collected information touching their properties, their changes, their relationships; but to him, as to his less scientific neighbor, they are the same things they always were,—things that he has known from the days of childhood.
Perhaps it will be admitted that this is true of such sciences as those above indicated, but doubted whether it is true of all the sciences, even of all the sciences which are directly concerned with things of some sort. For example, to the plain man the world of material things consists of things that can be seen and touched. Many of these seem to fill space continuously. They may be divided, but the parts into which they may be divided are conceived as fragments of the things, and as of the same general nature as the wholes of which they are parts. Yet the chemist and the physicist tell us that these same extended things are not really continuous, as they seem to us to be, but consist of swarms of imperceptible atoms, in rapid motion, at considerable distances from one another in space, and grouped in various ways.
What has now become of the world of realities to which the plain man pinned his faith? It has come to be looked upon as a world of appearances, of phenomena, of manifestations, under which the real things, themselves imperceptible, make their presence evident to our senses. Is this new, real world the world of things in which the plain man finds himself, and in which he has felt so much at home?
A closer scrutiny reveals that the world of atoms and molecules into which the man of science resolves the system of material things is not, after all, so very different in kind from the world to which the plain man is accustomed. He can understand without difficulty the language in which it is described to him, and he can readily see how a man may be led to assume its existence.
The atom is not, it is true, directly perceivable by sense, but it is conceived as though it and its motions were thus perceivable. The plain man has long known that things consist of parts which remain, under some circumstances, invisible. When he approaches an object from a distance, he sees parts which he could not see before; and what appears to the naked eye a mere speck without perceptible parts is found under the microscope to be an insect with its full complement of members. Moreover, he has often observed that objects which appear continuous when seen from a distance are evidently far from continuous when seen close at hand. As we walk toward a tree we can see the indefinite mass of color break up into discontinuous patches; a fabric, which presents the appearance of an unbroken surface when viewed in certain ways may be seen to be riddled with holes when held between the eye and the light. There is no man who has not some acquaintance with the distinction between appearance and reality, and who does not make use of the distinction in common life.
Nor can it seem a surprising fact that different combinations of atoms should exhibit different properties. Have we not always known that things in combination are apt to have different properties from the same things taken separately? He who does not know so much as this is not fit even to be a cook.
No, the imperceptible world of atoms and molecules is not by any means totally different from the world of things in which the plain man lives. These little objects and groups of objects are discussed very much as we discuss the larger objects and groups of objects to which we are accustomed. We are still concerned with things which exist in space and move about in space; and even if these things are small and are not very familiarly known, no intellectual revolution is demanded to enable a man to understand the words of the scientist who is talking about them, and to understand as well the sort of reasonings upon which the doctrine is based.
9. MATHEMATICS.—Let us now turn to take a glance at the mathematical sciences. Of course, these have to do with things sooner or later, for our mathematical reasonings would be absolutely useless to us if they could not be applied to the world of things; but in mathematical reasonings we abstract from things for the time being, confident that we can come back to them when we want to do so, and can make use of the results obtained in our operations.
Now, every civilized man who is not mentally deficient can perform the fundamental operations of arithmetic. He can add and subtract, multiply and divide. In other words, he can use numbers. The man who has become an accomplished mathematician can use numbers much better; but if we are capable of following intelligently the intricate series of operations that he carries out on the paper before us, and can see the significance of the system of signs which he uses as an aid, we shall realize that he is only doing in more complicated ways what we have been accustomed to do almost from our childhood.
If we are interested, not so much in performing the operations, as in inquiring into what really takes place in a mind when several units are grasped together and made into a new unit,—for example, when twelve units are thought as one dozen,—the mathematician has a right to say: I leave all that to the psychologist or to the metaphysician; every one knows in a general way what is meant by a unit, and knows that units can be added and subtracted, grouped and separated; I only undertake to show how one may avoid error in doing these things.
It is with geometry as it is with arithmetic. No man is wholly ignorant of points, lines, surfaces, and solids. We are all aware that a short line is not a point, a narrow surface is not a line, and a thin solid is not a mere surface. A door so thin as to have only one side would be repudiated by every man of sense as a monstrosity. When the geometrician defines for us the point, the line, the surface, and the solid, and when he sets before us an array of axioms, or self-evident truths, we follow him with confidence because he seems to be telling us things that we can directly see to be reasonable; indeed, to be telling us things that we have always known.
The truth is that the geometrician does not introduce us to a new world at all. He merely gives us a fuller and a more exact account than was before within our reach of the space relations which obtain in the world of external objects, a world we already know pretty well.
Suppose that we say to him: You have spent many years in dividing up space and in scrutinizing the relations that are to be discovered in that realm; now tell us, what is space? Is it real? Is it a thing, or a quality of a thing, or merely a relation between things? And how can any man think space, when the ideas through which he must think it are supposed to be themselves non-extended? The space itself is not supposed to be in the mind; how can a collection of non-extended ideas give any inkling of what is meant by extension?
Would any teacher of mathematics dream of discussing these questions with his class before proceeding to the proof of his propositions? It is generally admitted that, if such questions are to be answered at all, it is not with the aid of geometrical reasonings that they will be answered.
10. THE SCIENCE OF PSYCHOLOGY.—Now let us come back to a science which has to do directly with things. We have seen that the plain man has some knowledge of minds as well as of material things. Every one admits that the psychologist knows minds better. May we say that his knowledge of minds differs from that of the plain man about as the knowledge of plants possessed by the botanist differs from that of all intelligent persons who have cared to notice them? Or is it a knowledge of a quite different kind?
Those who are familiar with the development of the sciences within recent years have had occasion to remark the fact that psychology has been coming more and more to take its place as an independent science. Formerly it was regarded as part of the duty of the philosopher to treat of the mind and its knowledge; but the psychologist who pretends to be no more than a psychologist is a product of recent times. This tendency toward specialization is a natural thing, and is quite in line with what has taken place in other fields of investigation.
When any science becomes an independent discipline, it is recognized that it is a more or less limited field in which work of a certain kind is done in a certain way. Other fields and other kinds of work are to some extent ignored. But it is quite to be expected that there should be some dispute, especially at first, as to what does or does not properly fall within the limits of a given science. Where these limits shall be placed is, after all, a matter of convenience; and sometimes it is not well to be too strict in marking off one field from another. It is well to watch the actual development of a science, and to note the direction instinctively taken by investigators in that particular field.
If we compare the psychology of a generation or so ago with that of the present day, we cannot but be struck with the fact that there is an increasing tendency to treat psychology as a natural science. By this is not meant, of course, that there is no difference between psychology and the sciences that concern themselves with the world of material things—psychology has to do primarily with minds and not with bodies. But it is meant that, as the other sciences improve upon the knowledge of the plain man without wholly recasting it, as they accept the world in which he finds himself and merely attempt to give us a better account of it, so the psychologist may accept the world of matter and of minds recognized by common thought, and may devote himself to the study of minds, without attempting to solve a class of problems discussed by the metaphysician. For example, he may refuse to discuss the question whether the mind can really know that there is an external world with which it stands in relation, and from which it receives messages along the avenues of the senses. He may claim that it is no more his business to treat of this than it is the business of the mathematician to treat of the ultimate nature of space.
Thus the psychologist assumes without question the existence of an external real world, a world of matter and motion. He finds in this world certain organized bodies that present phenomena which he regards as indicative of the presence of minds. He accepts it as a fact that each mind knows its own states directly, and knows everything else by inference from those states, receiving messages from the outer world along one set of nerves and reacting along another set. He conceives of minds as wholly dependent upon messages thus conveyed to them from without. He tells us how a mind, by the aid of such messages, gradually builds up for itself the notion of the external world and of the other minds which are connected with bodies to be found in that world.
We may fairly say that all this is merely a development of and an improvement upon the plain man's knowledge of minds and of bodies. There is no normal man who does not know that his mind is more intimately related to his body than it is to other bodies. We all distinguish between our ideas of things and the external things they represent, and we believe that our knowledge of things comes to us through the avenues of the senses. Must we not open our eyes to see, and unstop our ears to hear? We all know that we do not perceive other minds directly, but must infer their contents from what takes place in the bodies to which they are referred—from words and actions. Moreover, we know that a knowledge of the outer world and of other minds is built up gradually, and we never think of an infant as knowing what a man knows, much as we are inclined to overrate the minds of infants.
The fact that the plain man and the psychologist do not greatly differ in their point of view must impress every one who is charged with the task of introducing students to the study of psychology and philosophy. It is rather an easy thing to make them follow the reasonings of the psychologist, so long as he avoids metaphysical reflections. The assumptions which he makes seem to them not unreasonable; and, as for his methods of investigation, there is no one of them which they have not already employed themselves in a more or less blundering way. They have had recourse to introspection, i.e. they have noticed the phenomena of their own minds; they have made use of the objective method, i.e. they have observed the signs of mind exhibited by other persons and by the brutes; they have sometimes experimented—this is done by the schoolgirl who tries to find out how best to tease her roommate, and by the boy who covers and uncovers his ears in church to make the preacher sing a tune.
It may not be easy to make men good psychologists, but it is certainly not difficult to make them understand what the psychologist is doing and to make them realize the value of his work. He, like the workers in the other natural sciences, takes for granted the world of the plain man, the world of material things in space and time and of minds related to those material things. But when it is a question of introducing the student to the reflections of the philosophers the case is very different. We seem to be enticing him into a new and a strange world, and he is apt to be filled with suspicion and distrust. The most familiar things take on an unfamiliar aspect, and questions are raised which it strikes the unreflective man as highly absurd even to propose. Of this world of reflective thought I shall say just a word in what follows.
11. REFLECTIVE THOUGHT.—If we ask our neighbor to meet us somewhere at a given hour, he has no difficulty in understanding what we have requested him to do. If he wishes to do so, he can be on the spot at the proper moment. He may never have asked himself in his whole life what he means by space and by time. He may be quite ignorant that thoughtful men have disputed concerning the nature of these for centuries past.
And a man may go through the world avoiding disaster year after year by distinguishing with some success between what is real and what is not real, and yet he may be quite unable to tell us what, in general, it means for a thing to be real. Some things are real and some are not; as a rule he seems to be able to discover the difference; of his method of procedure he has never tried to give an account to himself.
That he has a mind he cannot doubt, and he has some idea of the difference between it and certain other minds; but even the most ardent champion of the plain man must admit that he has the most hazy of notions touching the nature of his mind. He seems to be more doubtful concerning the nature of the mind and its knowledge than he is concerning the nature of external things. Certainly he appears to be more willing to admit his ignorance in this realm.
And yet the man can hold his own in the world of real things. He can distinguish between this thing and that, this place and that, this time and that. He can think out a plan and carry it into execution; he can guess at the contents of other minds and allow this knowledge to find its place in his plan.
All of which proves that our knowledge is not necessarily useless because it is rather dim and vague. It is one thing to use a mental state; it is another to have a clear comprehension of just what it is and of what elements it may be made up.