18 PROGRESS OF SCIENCE IN THE CENTURY. 



at once in our minds when we try to explain human 

 action is irrelevant in physical seienca 



On the same subject, Dr. J. T. Merz writes as 

 follows in his impressive history of scientific thought 

 in the nineteenth century : " A complete and simple 

 description admitting of calculation is the aim of 

 all exact science. . . . We shall not expect to find 

 the ultimate and final causes, and science will not 

 teach us to understand nature and life. . . . Science 

 means * the analysis of phenomena as to their ap- 

 pearance in space and their sequence in time.' " * 



Thus the common assertion that science gives ex- 

 planations of nature is a misunderstanding, if the 

 word explanation is taken to mean more than a de- 

 scriptive formula. The word ultimate does not oc- 

 cur in the scientific dictionary. The biologist draws 

 cheques, but they are all backed by such words as 

 protoplasm and germ-plasm; and a little enquiry 

 suffices to show that these words imply conceptual 

 hypotheses invented to express the facts and war- 

 ranted by the success with which they fit these. The 

 physicist's bills, similarly, are accepted on the credit 

 of the ubiquitous ether, the mighty atom, or the like, 

 but these again are conceptual hypotheses invented 

 to summarise the sequence of phenomena. 



Let us take a concrete case. " The law of gravi- 

 tation is a brief description of how every particle of 

 matter in the universe is altering its motion with 

 reference to every other particle. It does not tell 

 us why particles thus move; it does not tell us why 

 the earth describes a certain curve round the sun. It 

 simply resumes, in a few brief words, the relation- 



* J. T. Merz. A History of European Thought in the Nine- 

 teenth Century. Vol. I., Introduction Scientific Thought, 

 Part I., 1896, pp. 382-3. 



