level, because . . ." The evident point of the parable is that the keen observer and the speculative hermit are both combined in a trained scientific investigator; he performs the two tasks of observation and of explanation independently, as if he were two persons; and his philosophical half finally accepts as true that particular scheme or theory which leads to the best understanding of the facts gained by his observational half.

THE ESSAYS AS MODELS OF EXPOSITION

The third reading is devoted to the style of presentation, and this brings the reader more closely into relation with the author. The object of the third reading is thus unlike that of the second, which considered the author in relation to his problem; while both these are unlike the first, in which the reader did not think of the author but only of the subject treated. A few leading characteristics of presentation in the first, essay may be pointed out; the reader may afterward make for himself a similar analysis of the second essay. Note first that the more difficult subject of light is introduced by the analogous and easier subject of sound (pp. 264-268); this is as if the author kindly took the reader by the hand and guided him along an easy path toward a lofty summit. Note again the care which the author takes to lead the reader by easy steps from small to large numbers, and the sympathetic encouragement that he gives: "You can all understand it" (p. 270). Consider the homely illustration of the teapot (p. 271) and the large concept which it aids you in reaching. Recognize the personal touch given by the reference to the famous work of the American physicist, Langley (p. 272); and a little later to the epoch-making discovery of the spectrum by Newton. See again a homely illustration in the mention of shoemaker's wax, and with it Kelvin's quaint allusion to his Scotch birth (p. 276). Passing over several other matters, consider the care which this profound investigator, himself able to grasp the most complicated mathematical formulæ, gives to illustrating the nature of ether vibrations by means of a small red ball in a bowl of jelly (p. 284).

The first reading ought to excite a desire to learn more about light; the second, to understand more fully the method of science; the third, to know more intimately some of the great men of the world. Thus the careful reading of one thing creates an appetite for reading many other things: and therein lies the greatest teaching value of any reading whatever.

S

PHILOSOPHY

1. GENERAL INTRODUCTION

BY PROFESSOR RALPH BARTON PERRY

How charming is divine philosophy!
Not harsh and crabbed, as dull fools suppose,
But musical as is Apollo's lute,

And a perpetual feast of nectar'd sweets,
Where no crude surfeit reigns.

INCE Milton wrote thus gallantly in its behalf, phi

losophy has fairly succeeded in living down its reputation for being "harsh and crabbed." No one who has made the acquaintance of Scholastic Philosophy, the philosophy of the Middle Ages, and still the established philosophy in Milton's day, can escape a secret sympathy with the view of these "dull fools." But in the course of the last three centuries, philosophy, especially English and French philosophy, has become more free in form, more imaginative, and more self-expressive. So that the critics and belittlers of philosophy to-day, too numerous, alas! to make it safe to call names, have taken up new ground. Philosophy is condemned, not for being unmusical, but for being unpractical. The music of Apollo's lute is itself under suspicion, being too unsubstantial and too remote to suit the temper of an age of efficiency and common sense.

PHILOSOPHY AND EFFICIENCY

I sincerely wish that I could recommend philosophy on grounds of efficiency and common sense. I should be listened to, understood, and believed. I should at once insinuate myself into the confidence of my reader. If I could but say: "Now look here! Philosophy is just a matter of, plain, hard-headed common sense"; or, "If you want to succeed, try philosophy. It will help you to make and to

sell, to outstrip competitors, and to be efficient in whatever you undertake"; if I could make such an appeal to you, your instincts and prejudices would secure me your ready sympathy. But I should have deceived you. What I should thus have recommended to you would not be philosophy. For philosophy is neither plain nor hard-headed; nor is it a means of success, as success is ordinarily construed. This is the case, not accidentaliy, but in principle. The very point of philosophy lies in the fallibility of common sense, and in the arbitrariness of vulgar standards of success. Philosophy is one of those things that must be met on its own ground. You must seek it where it is at home; if you insist upon its meeting you halfway it will turn out not to be philosophy at all, but some poor compromise-the name or husk of philosophy with the soul gone out of it. No one can understand what philosophy means unless he lets it speak for itself and in its own language. If philosophy is good, it is because it contributes to life something different, something peculiarly its own, and which cannot be measured by any standards save those which philosophy itself supplies.

PHILOSOPHY AND COMMON SENSE

If we cannot justify philosophy by common sense, we can at least contrast it with common sense, and so approach it from that more familiar ground. Since we must admit that philosophy is at odds with common sense, let us make the most of it. What, then, is common sense? First of all it is evident that this is not a common-sense question. One of the things peculiar to common sense is that it must not be questioned, but taken for granted. It is made up of a mass of convictions that by common consent are to be allowed to stand; one does not ask questions about them, but appeals to them to determine what questions shall be asked. They are the conservative opinion, the solidified and uniform belief, on which men act, and which is the unconscious premise of most human reasoning. As a man of common sense, I use common sense to live by or to think by; it is a practical and theoretical bias which I share with my fellows, but which I do not think about at all.

Now suppose that in some whimsical and senseless mood I do think about common sense. Something very startling happens. This once unchallenged authority is proved to be highly fallible. Its spell is gone. It at once appears, for example, that common sense has had a history, and that it has varied with times and places. The absurdities of yesterday are the common sense of to-day; the common sense of yesterday is now obsolete and quaint. The crank of the sixteenth century was the man who said that the earth moved; the crank of the twentieth century is the man who says that it does not. Moreover, once common sense is thus reflected upon, it is seen to be in part, at least, the result of wholly irrational forces, such as habit and imitation. What has been long believed, or repeatedly asserted, acquires a hardness and fixity from that fact; in the future it is always easier to believe, more difficult to disbelieve, than anything recent or novel. And what others about us believe, we tend unconsciously to reflect in our own belief, just as our speech catches the accent and idioms of our social circle. Furthermore, a belief once widely diffused takes on the authority of established usage. It is supported by public opinion, as anything normal or regular is supported; unbelievers are viewed with hostile suspicion as unreliable and incalculable. "You can never tell what they will do next." Or they are forcibly persecuted as a menace to the public peace. I have called habit and imitation "irrational" forces. By that I mean that they have no special regard for truth. They operate in the same way to confirm and propagate a bad way of thinking as a good way of thinking. It does not follow that common sense is necessarily mistaken; indeed reasons can be adduced to show that common sense is a very good guide indeed. But if so, then common sense is justified on other grounds; it is not itself the last court of appeal. Common sense, despite its stability and vogue, perhaps on account of its stability and vogue, is open to criticism. We cannot be sure that it is true; and it may positively stand in the way of truth through giving an unwarranted authority to the old and familiar, and through shutting our minds so that no new light can get in.

The philosopher, then, is one who at the risk of being