Nature of the Universe 13 



Many biologists forget this, they forget the fact 

 that they have deliberately restricted their observa- 

 tion and reasoning to a certain group of phenomena. 

 Ignoring this restriction, they speak positively for 

 biological material in the unrestricted sense. They 

 thus present an imperfect and essentially unsound and 

 incorrect picture of the world of living things. The 

 picture that is thus given is fundamentally different 

 from the picture that is obtained when we include all 

 the phenomena ; when we include sensations, emotions, 

 ideas, and other mental characteristics. 



For the understanding of the present lectures, it is 

 important to grasp clearly the fact that such a course 

 of action, such an ignoring of the inner phenomena of 

 life, appears to the lecturer to vitiate many of the 

 conclusions drawn by biological investigators and 

 indeed to lead to fundamental errors. When the pur- 

 pose is, as in the present lectures, to give a general 

 picture of biological things in their relation to the 

 rest of the world, we must include what we discover 

 through both methods of approach. The things we 

 discover through the fact that you and I are biologi- 

 cal specimens must be considered on the same basis as 

 the data obtained in other ways. 



This is not the only example in science of exclud- 

 ing from consideration certain kinds of data. It is 

 sometimes urged that only what is quantitative is 

 science; all qualitative differences and changes fall 

 outside its scope. Or again we are told that only 

 matter in motion, only mechanism, or only energy, 

 constitutes the field of science ; that all experiences or 



