Nature of the Universe 7 



present them only as inferences that are based upon 

 positive science and are consistent with it. 



One further prehminary point is of great impor- 

 tance for understanding what I shall try to present. 

 If we are to keep in the spirit of science, we must 

 make only inferences of the same kind that we make in 

 positive science, though these inferences may reach 

 out into regions in which it is not possible to test them. 

 This means, in the main, that we must try to limit our- 

 selves to drawing conclusions as to the extension, in 

 space and time, of the same types of things that are 

 observed and dealt with in positive science. For ex- 

 ample, we shall have to talk of the probable future of 

 life on the earth and of life elsewhere, and of the 

 changes that life may undergo. To limit our conclu- 

 sions in this way will be our ideal ; it limits our under- 

 taking in very definite ways. 



But keeping within these limits, I am myself con- 

 vinced that the study of biology, the study of living 

 things in their relation to the world, does lead to a 

 definite positive outlook on the matters which we have 

 suggested as included in religion. It does help, it seems 

 to me, in getting a unified view of the universe and of 

 man in his relations with it. It adds some things of 

 great importance to the view of things which physics 

 presents to us. And it helps particularly in the prob- 

 lems of managing life, the problems of conduct, and 

 in determining our attitude toward the world. In or- 

 der to bring out this outlook and its suggestions, we 

 shall devote ourselves, in this lecture and the next, to 

 outlining a picture of what biology shows us ; to the 



