An Introduction to Philosophy by George Stuart Fullerton (bookreader TXT) 📖

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