62 PROGRESS OF SCIENCE IN THE CENTURY. 



member of a family, a unit in a fauna, a thread in 

 the web of life. 



And although we have taken our illustrations from 

 biology, the same condition of progress applies to the 

 other sciences. That man cannot be studied to much 

 purpose, if he is persistently held in artificial isola- 

 tion, is as certain as is the impossibility of under- 

 standing the earth apart from the solar system, 

 x^ To sum up, three important factors in the progress 

 of science are : a fuller recognition that science is 

 for life and not life for science, a more practical ap- 

 preciation of the benefits of co-operation between 

 different disciplines, and a frank acknowledgment 

 that analysis is a means not at end. 



But there is another important factor ; namely, the 

 improvement of methods, of devices by which we 

 not only extend the range of our sense-experience but 

 intensify our powers of precision. To give an ac- 

 count of the development of methods would be to 

 write half of the history of science, and we must refer 

 for illustration to the separate chapters of this book. 

 But how much progress is suggested when we recall 

 the methods of quantitative analysis in chemistry, of 

 measuring the different forms of energy in physics, 

 of spectrum analysis in astronomy, of microscopic 

 technique in biology, of experiment in psychology. 

 Apart altogether from instrumental devices, the in- 

 creasing use of mathematical and statistical methods 

 in dealing with the problems of biology furnishes a 

 good illustration of the fact that the rate of progress 

 ifl partly dependent on the methods employed. 



JUSTIFICATION OF SCIENCE. 



If science be a natural and necessary expression of 



