Science and Philosophy 57 



misleading, it can do considerable good 

 by criticising and stimulating and inform- 

 ing ; and it is an interesting fact that 

 a man so well acquainted with biology as 

 Professor Haeckel is should have been so 

 strongly impressed with the truth of some 

 aspect of the philosophic system known as 

 Monism. Many men of science have like- 

 wise been impressed with the probability, or 

 possibility, of some such ultimate unification. 



The problem to be solved and an old- 

 world problem indeed it is is the range, and 

 especially the nature, of the connection 

 between mind and matter ; or, let us say, 

 between the material universe on the one 

 hand, and the vital, the mental, the con- 

 scious and spiritual universe or universes, 

 on the other. 



It would be extremely surprising if 

 any attempt yet made had already been 

 thoroughly successful, though the attack on 

 the idealistic side appears to many of us 

 physicists to be by far the most hopeful line 

 of advance. An excessively wide know- 



