rebound of materialism, reaching its climax in the positivism of Auguste Comte, and the extremes of that idealism have almost justified the extremes, also, of the empirical school.

At present we see a rebound from materialism and empiricism. The result is twofold. Wherever philosophic thought has grown languid and weak under the opiate influences of materialism and skepticism, wherever it merely has power to lift itself up and be heard, it seems to totter into mere agnosticism; but wherever, on the contrary, philosophic thought has retained some of the manly vigor which recognizes that the human intellect is not made for nescience but for knowledge, not made for darkness but for light, then philosophy stands up and asserts itself, asserts its right to remind science that it does not fill the whole world of human thinking, and demands that those relations between science and philosophy shall be remembered and shall be observed, upon which the reasonableness or utility of both equally depends.

What are those relations? Science works according to certain principles which it presupposes. These principles are very elementary. The whole is, and must be, greater than any of its parts. All the operations of nature take place, and must take place, in space and in time. Every effect presupposes, and must presuppose, a cause; and is, and must be, proportionate to its cause. Nature itself is a reality and not a fiction. It has in it those elements that make it possible for a man from facts to rise to laws and from laws to build up systems. All the notions of equality and inequality, of proportion and relation-all these things science works with, all these things science presupposes. Science did not make them, science did not discover them, science did not receive them even from mathematics. Mathematics, itself, presupposes them and works with them. Where do they come from? The scientist may accept these principles unconsciously, he may forget his debt to philosophy, but he does not by that forgetfulness cancel the debt.

More than that, when a science has done its best, and by the application of these principles has made and tested its methods, carried on its observations and then tested its results, all is not done. These single facts have to be woven, have to be fixed into the great mosaic of truth. Science stands side by side with other sciences, and the scientist in any department must every now and then, if he is loyal to human intelligence, look over the fence of his own narrow boundary, recognize the fields of thought that are beyond

him, estimate the relation and agreement between his results and those which they are working out, and not merely try to estimate how it is as between him and his nearest neighbor in the departments of science, but how it is between him and them all.

Who is going to do this? No individual science can do it; no mere coming together of all the sciences can accomplish it. An arbiter is needed, an arbiter that can stand on a hilltop and survey all; and that arbiter of all the sciences-the one that stands on the hilltop and corrects blunders and utters notes of warning, and knows how, from hypotheses, to sift out certitudes and from mistakes to sift out truths, and to take all the little bits that each supplies and weave them in the harmony of truth-is philosophy; and the fact that her point of view is so much higher and so much more comprehensive than that of any science in particular, enables her to direct the sciences in their work and to point out any part of the great horizon in which the light is seen to be breaking forth.

Such is the natural relation between science and philosophy, the relation that they must have in the nature of things. How is it de facto in the age in which we live? It is a noteworthy fact that, in our age, so many scientific men are developing into philosophic thinkers. Wundt, after writing on physics, physiology and experimental psychology, gives us his system of philosophy. Mivart, while plying his scalpel, learns for himself and publishes to the world the deeper lessons from nature and the higher meaning of truth and the value and method of reasoning. From the physiological laboratory Du Bois Raymond surveys the Seven World Riddles, and Lewes launches out into the problems of life and mind.

These facts, simple indications of multitudes that might be enumerated, show that the most accurate scientific research is compatible with the profoundest philosophic thinking. Nay, more, it shows that science-when it is loyal to truth, when it is logical, when it is consistent, when it is human-must lead up to philosophic thinking. The same appears when we institute a comparison between the methods of science and of philosophy. First of all, let us observe that every science has its own specialties of method which no other science may share with it. The physicist has one method, the chemist has another, so have the biologist and the astronomer.

But these differences of detail in the methods of the individual

sciences do not, by any means, prove any incompatibility between the sciences or their general methods. Apply the truth, and we recognize at once that, while there must exist distinctive differences between the methods of any science, or of all the sciences, and the methods of philosophy, these distinctive differences are no proof of incompatibility between philosophy and sciences or between their methods.

More than that, the method observed by all sciences is, in its ultimate analysis, generalization, which is a process of abstraction. Without generalization, without abstraction, it would be simply impossible to rise from the notion of fact to the notion of law. When the chemist finds that this oxygen, in this balloon, takes just so much of this hydrogen in this balloon in order to combine into water, he extends this proportion to all oxygen and all hydrogen, and to all experiments with them-past, present and to come-not by scientific observation, but by generalization, by abstraction, by the fundamental process of all thinking. When the physicist finds that this piece of spar gives double refraction, he concludes the same of all samples of that substance, and that without at all needing to experiment with the rest. When the physiologist finds that the blood in this man is composed of white and red corpuscles, he does not need to dissect all mankind in order to reach the conclusion that the blood of every man is composed in the same way. Thus we recognize that science is constantly making use of one great operation, which is the fundamental unity of all scientific method, and that is generalization, abstraction.

Then comes the mathematician, whose method means abstraction on a higher plane. He shows that two and two make four, whether it be two and two atoms, or two and two planets, or two and two ideas; and he applies his principles of number and weight and measure, his notions of quality and equality and proportion, to all things, and works out at his desk the system of the universe. It is a remarkable fact that the great fundamental, dominant principle of all physical science in our age, the conservation of force, was wrought out mathematically, by Leibnitz, one hundred and fifty years before it was proved experimentally by Joule.

One step more up that ladder of abstraction and we reach the operations of philosophy. It widens our view, giving us not merely the perspective of this science and of that science and of all sciences lying side by side, interlacing and working together in the

production of the world's harmony, but it opens before us a perspective that embraces all things, a perspective embracing the infinite and the atom, with all the intervening grades of force and of life, the grand hierarchy of being, of causing, of becoming; therefore, the advance from science to philosophy is but an ascent from one grade of abstraction to another, without jar or hindrance, for those whose minds are keen enough for analysis and broad enough for synthesis.

What is What is the

What is the

Yet another motive which leads, or rather forces, the logical scientist into philosophy is the fact that problems exist and demand a solution which no amount of scientific research can solve. the origin of all? What is the aim of evolution? nature of the human soul, its whence, its whither? real value of human life? What are its duties, its rewards, its destiny? Any individual scientist may brush these questions aside, but there they stand, they confront mankind, they ever have confronted mankind, they ever have forced mankind to its highest and its deepest and its noblest thinking. They demand a reply, they prove with the very evidence of intuition that a reply to these problems is of greater importance than a reply to any of the problems ever started by physics or by chemistry; and just in proportion as special research drifts away from facing these problems they cry out all the more loudly in the ear of humanity and tell man that he dare not ignore them. The man who stands ankle deep in the rivulet may laugh at the shallowness of the little stream, but his merriment does not fathom the sea into which that stream and a thousand others are pouring; and to sound the depths of that all-comprising truth into which the separate branches of knowledge empty their threads of facts is the proper office of philosophy.

What system of philosophy is going to do this? What system of philosophy can we Americans at the close of the nineteenth century accept? It must be a philosophy that shall have an eye on the past and an eye on the future; that is to say, first, it must be a fair and balanced philosophy that shall avoid extremes, extremes which are fatal alike to empirical and to speculative thought. It must avoid one-sidedness, it must keep clear of materialism and of idealism, of skepticism and of dogmatism, of pantheism and of atheism; it must be balanced, it must be an all-around philosophy, it must be the via media. Secondly, it must be adaptable, it must be firm enough to hold fast to every addition which science may make to

the sum total of human knowledge, fearless enough to welcome them all, knowing that fact can never contradict fact and that truth can never be in antagonism to truth; and it must be elastic enough to meet the result of philosophic research, holding on to what is, pressing on to what is to come. It must be, in the third place, a reflection of all those elements which in the development of thought persist because true.

We have men around us building up grand systems of philosophy and those systems die one after another, and yet, as the scientist shows us to-day the structure of the beings that lived ages and ages ago and left a substratum of fact after them, so these systems of thought that come and go and die leave something after them. No system of thought is totally false, though few systems of thought can claim to be totally true. And so our system of philosophy must be able to hold on to all that is true, no matter where it comes from, to hold on to the persistent, to hold on to that which is eternal because it is true.

May I be permitted in conclusion to ask your attention to what some may consider a singular fact in the world of thought at the close of the nineteenth century. Let me ask your attention to that grand old man whom we Catholics I think have a right to be proud of, Leo XIII, who on the one hand calls the world again to study the old scholastic philosophy, and, on the other hand, endows out of his own means astronomical observatories and laboratories of physics and of chemistry. That man is convinced that there is in that old philosophy a body of principles that are the truth, a body of principles that therefore are everlasting, a body of principles that therefore can guide science as well at the end of the nineteenth century as they did in the middle of the thirteenth. He shows that that philosophy is not a fossil, but a system of living principles ready to take in all that the scalpel, the retort and the lens can ever show us, and to teach all the wondrous progress of the science of the future how it is to weave itself into the great harmony of truth and is yet to shed its refulgence on the world. He shows us that it is possible for a system devised by Aristotle and developed by Aquinas to receive yet further development, and to answer yet or to help mankind to answer all the mighty problems in nature and above it that press upon the mind of man.

Shall not America do something towards helping the world to

PROC. AMER. PHILOS. SOC. XXXII. 143. F. PRINTED NOV. 22, 1893.