If we study mathematics, or chemistry, or physics, or physiology, or biology, the effort is made to lay before us in a convenient form the latest results which have been attained in those sciences. Of their history very little is said; and, indeed, as we have seen (section 6), lectures on the history of the inductive sciences are apt to be regarded as philosophical in their character and aims rather than as merely scientific.
The interest in the history of philosophy is certainly not a diminishing one. Text-books covering the whole field or a part of it are multiplied; extensive studies are made and published covering the work of individual philosophers; innumerable historical discussions make their appearance in the pages of current philosophical journals. No student is regarded as fairly acquainted with philosophy who knows nothing of Plato and Aristotle, Descartes and Spinoza, Berkeley and Hume, Kant and Hegel, and the rest. We should look upon him as having a very restricted outlook if he had read only the works of the thinkers of our own day; indeed, we should not expect him to have a proper comprehension even of these, for their chapters must remain blind and meaningless to one who has no knowledge of what preceded them and has given birth to the doctrines there set forth.
It is a fair question to ask: Why is philosophy so bound up with the study of the past? Why may we not content ourselves with what has up to the present been attained, and omit a survey of the road along which our predecessors have traveled?
84. THE ESPECIAL IMPORTANCE OF HISTORICAL STUDIES TO REFLECTIVE THOUGHT.—In some of the preceding chapters dealing with the various philosophical sciences, it has been indicated that, in the sciences we do not regard as philosophical, men may work on the basis of certain commonly accepted assumptions and employ methods which are generally regarded as trustworthy within the given field. The value both of the fundamental assumptions and of the methods of investigation appear to be guaranteed by the results attained. There are not merely observation and hypothesis; there is also verification, and where this is lacking, men either abandon their position or reserve their judgment.
Thus, a certain body of interrelated facts is built up, the significance of which, in many fields at least, is apparent even to the layman. Nor is it wholly beyond him to judge whether the results of scientific investigations can be verified. An eclipse, calculated by methods which he is quite unable to follow, may occur at the appointed hour and confirm his respect for the astronomer. The efficacy of a serum in the cure of diseases may convince him that work done in the laboratory is not labor lost.
It seems evident that the several sciences do really rise on stepping stones of their dead selves, and that those selves of the past are really dead and superseded. Who would now think of going back for his science to Plato's "Timaeus," or would accept the description of the physical world contained in the works of Aristotle? What chemist or physicist need busy himself with the doctrine of atoms and their clashings presented in the magnificent poem of Lucretius? Who can forbear a smile—a sympathetic one—when he turns over the pages of Augustine's "City of God," and sees what sort of a world this remarkable man believed himself to inhabit?
It is the historic and human interest that carries us back to these things. We say: What ingenuity! what a happy guess! how well that was reasoned in the light of what was actually known about the world in those days! But we never forget that what compels our admiration does so because it makes us realize that we stand in the presence of a great mind, and not because it is a foundation-stone in the great edifice which science has erected.
But it is not so in philosophy. It is not possible to regard the philosophical reflections of Plato and of Aristotle as superseded in the same sense in which we may so regard their science. The reason for this lies in the difference between scientific thought and reflective thought.
The two have been contrasted in Chapter II of this volume. It was there pointed out that the sort of thinking demanded in the special sciences is not so very different from that with which we are all familiar in common life. Science is more accurate and systematic, it has a broader outlook, and it is free from the imperfections which vitiate the uncritical and fragmentary knowledge which experience of the world yields the unscientific. But, after all, the world is much the same sort of a world to the man of science and to his uncritical neighbor. The latter can, as we have seen, understand what, in general, the former is doing, and can appropriate many of his results.
On the other hand, it often happens that the man who has not, with pains and labor, learned to reflect, cannot even see that the philosopher has a genuine problem before him. Thus, the plain man accepts the fact that he has a mind and that it knows the world. That both mental phenomena and physical phenomena should be carefully observed and classified he may be ready to admit. But that the very conceptions of mind and of what it means to know a world are vague and indefinite in the extreme, and stand in need of careful analysis, he does not realize.