conclusions of philosophy can not meet. In so far as they do so they are conclusions of science. As science advances in any field philosophy is driven away from it. The fact has been often noted that every great conclusion of science has been anticipated by philosophy, in most cases by the philosophy of the Greeks. But every conclusion science has shown to be false has been likewise anticipated. The Greeks taught the theory of development centuries before Darwin. But if Darwin's studies in life variation had led to any other result whatsoever, he would have been equally anticipated by the Greeks. In other words, every conceivable guess as to the origin and meaning of familiar phenomena has been exhausted by philosophy. Some of these guesses contain elements of truth. Which of these have such elements it is the business of Science to find out. Philosophy has no means of doing so. A truth not yet shown to be true is in science not a truth. It has no more validity than any other generalization not shown to be false. Helmholtz tells us that philosophy deals with such "schlechtes Stoff," such bad subject-matter, that it can give no trustworthy conclusions. Science alone can give the test of human life. The essence of this test is experiment.
The tests of philosophy are mainly these: Is the conception plausible? Has it logical continuity? Is it satisfying to the human heart? And in this connection the figurative word "heart" is best left undefined. In other words, its sources and its tests are alike subjective—intellectual or emotional. If we take from philosophy the "heart" element, the personal equation, it becomes logic or mathematics. Mathematics is metaphysics working through methods of precision. It is a most valuable instrument for the study of the relations and ramifications of knowledge, but it can give no addition to knowledge itself. Dr. William James defines metaphysics as "the persistent attempt to think clearly." This definition is good so far as it goes, but to think clearly is a function of science also. Metaphysics is rather the "attempt to think clearly" in fields where exact data are unattained or unattainable. In so far as philosophy is simply clear thinking it is a most valuable agency for testing the deductions of science. But, while it can reject false conclusions, it can add no new matter of its own.
For example, the claim is made in the name of evolutionary philosophy that all matter is one in essence, therefore all the chemical elements, some seventy in number, must be the same in substance. In this case all must be derived from the same primitive stuff, and the hypothetical basis of all ponderable matter has been called protyl. As a working theory this is most ingenious. But is it science? Is it worthy of belief? Certainly Science
