26 AN INTRODUCTION TO SCIENCE 



boundaries of science and philosophy, when pressed to 

 their ultimate terms, may be summed up in the same way: 

 "Infinite science is bounded by philosophy," and vice 

 versa. 



\Ye may, of course, set aside as immaterial to our sub- 

 ject the sense which was given to the term Philosophy by 

 the Stoics a system of the principles of action which 

 regulate conduct a sense which still in its popular use 

 clings to the name. The only meaning in which philosophy 

 has any bearing upon our subject is that in which it stands 

 for an organised system of thought of the most abstract 

 kind ; thought which pierces as far as possible through the 

 visible husk of things into the principles which determine 

 their particular manifestations. From the earliest times 

 thinkers have not been content to believe that, when Man 

 knows the utmost that can be known about phenomena, 

 he knows the realities of which phenomena are the mani- 

 festations. Something unknowable is sought for behind the 

 outward mask which alone is, or ever will be, seen by 

 Man a universal principle, a soul, a deity, "an actuality 

 lying behind appearances." 



\Yith the philosophy of the Absolute a man of science 

 has no concern. His province, as man of science, ends at 

 the zone in which hypothesis can no longer be .checked 

 by observation or experiment. For working purposes he 

 accepts the axiom that "all statements which cannot be 

 confronted with objective tests are false." If no test can 

 be applied to them they are equally true and false to him. 

 Thinking about them is a waste of time. Science is the 

 elaborated product of observation. 



Yet, at the same time, the man of science, in common 

 with thinkers trained in other ways, knows that he has two 

 sources of information his senses and his inner conscious- 

 ness. When reflecting upon the mental processes by which 

 the materials supplied by the senses are worked into 

 thought, the Mind is watching its own activities. By self- 



