ii6 THE LIMITATIONS OF SCIENCE 



that the universe is so filled with matter that no straight 

 line can be drawn from the sun without reaching an 

 obstacle and so radiant energy is reflected back and 

 forth ; again the universe may be finite in size and its 

 boundary may be a reflecting surface. These hypotheses 

 are evidently futile speculations and no support to the 

 law which we have been driven to accept and shall 

 continue to accept until personal observation shows re- 

 sults which increasingly depart from the law. 



So, too, the law of cause and effect is a generaliza- 

 tion from few observations and neither supports nor is 

 supported by hypothesis. While we can never hope to 

 establish such a law, it is nevertheless a necessary gen- 

 eralization, or scientific deduction becomes meaningless. 

 The fact is, the phenomena of the universe do not re- 

 veal themselves, as a whole, in any regular sequence 

 of cause and effect ; and our theories, based on such a 

 law, show such a complex tangle as to be quite beyond 

 our power to interpret. The law involves time, and 

 past time at that; and the successive causes of an ob- 

 served phenomenon, if carried back in any logical 

 sequence, soon widen out into an incomprehensible 

 maze and vanish in the obscurity of the past. The 

 most beautiful and perfect example of this law is the 

 belief in organic evolution. Yet on what meager and 

 inaccurate observations it rests. Everyone believes in 

 some such law, but no one can point out the sequence 

 of cause and effect, and its rigorous development leads 



