NEW CONCEPTIONS LN SCIENCE 



Sir Isaac Newton knew very little of the world 

 about him. But with them and this is a capital 

 point we have come to know a great deal. We 

 have come, for one thing, to see that our senses 

 give us reports only of a comparatively small number 

 of comparatively gross stimuli. Professor Sully has 

 written an entertaining book, illustrating the way 

 in which our senses habitually delude us. It is en- 

 titled Illusions, and is a healthy piece of reading for 

 people who are filled up on some of the literature 

 very popular at this day. This study of illusions 

 is instructive enough and may well give us pause. 

 But it seems as if now we might go a little fur- 

 ther and affirm. Here might be a set of proposi- 

 tions to which I fancy there could, in the light 

 of present knowledge, be very little dissent: 



1. Sensation, thought, or consciousness cannot 

 be demonstrated, except as it is associated with 

 the physical substance of the brain and the nerves. 



2. This nerve substance is the sole path to the 

 mind it is the mind, and an exterior stimulus can 

 only reach us through the known organs of sense. 



3. While, on the one hand, we now know a great 

 number of stimuli which do not affect any of the 

 organs of sense, but do affect various instruments, 

 there are no stimuli known that affect the sense 

 organs which cannot be made to affect some instru- 

 ment in a far greater degree. It is only by means 



