SCIENCE, in its widest significance the correlation of all knowledge. To know a truth in its relation to other truths is to know it scientifically. For example, the recognition that the alternation of day and night depends on the apparent daily motion of the sun is a distinct sci entific achievement, being one of those elementary scientific truths which have been the possession of thinking minds from time immemorial.
The end of science is the rational in terpretation of the facts of existence as disclosed to us by our faculties and senses.
The scientific method is essentially in ductive, i. e., from particulars to gener alities, and is to be contrasted with the method of philosophy which is deductive, i. e., from general truths to particular truths. This distinction was first clearly indicated by Francis Bacon and elabo rated by Descartes and Comte. No bet ter instance of pure and extensive and scientific research can be cited than that pursued by Darwin in his biological in vestigations.
Experiment is the great aid to sci entific inquiry. In it we arbitrarily interfere with the circumstances of a phenomenon, or produce an entirely new phenomenon by an appropriate combina tion of causes. Contrasted with experi ment is observation, in which we simply watch and record the events as they oc cur in nature. But even in astronomy, emphatically an observational science, experiment plays an important part. The dynamical knowledge which Newton de veloped into the cosmic law of gravita tion was founded on experiment; and every time the astronomer points his tel escope to a celestial object he experi ments by arbitrarily interfering with the course of the rays of light. Meteorology
again, which 20 years ago could hardly be called a science, has made great strides in these days by appealing to laboratory experiments for the elucidation of its phenomena.
Sciences may be grouped, or science partitioned, on a broad and intelligible principle. There are the physical sci ences, which have to do with inorganic nature—i. e., with the laws and proper ties of matter, energy, and ether. Then there are the biological sciences, which consider the laws of life. And finally there are the psychical sciences, which deal with the phenomena of mind.
Numerous attempts have been made to give a detailed classification of the sci ences, so as to bring out the natural re lation of the one to the other, One of the most celebrated is the classification due to Comte, who first explicitly drew the distinction between abstract and con crete sciences, or what might better be termed fundamental and derivative sci ences (see PosiTivism). From the pres ent outlook of science the existences of the universe are five—namely, ether, matter, energy, life, and mind. The first three are inseparable agents in the sim plest phenomenon that occurs in nature. They may ultimately be reduced to two or conceivably to one.