696 THE POPULAR SCIENCE MONTHLY. 



the experiences of others, accepts them as the basis of his beliefs, in 

 preference to even the most vivid recollections of his dreams. 



The lunatic pauper, who regards himself as a king, the asylum in 

 which he is confined as a palace of regal splendor, and his keepers as 

 obsequious attendants, is so "possessed" by the conception framed by 

 his disordered intellect that he does project it out of himself into his 

 surroundings ; his refusal to admit the corrective teaching of common- 

 sense being the very essence of his malady. And there are not a few 

 persons abroad in the world who equally resist the teachings of edu- 

 cated common-sense whenever they run counter to their own precon- 

 ceptions, and who may be regarded as in so far affected with what 

 I once heard Mr. Carlyle pithily characterize as a " diluted insanity." 



It has been asserted over and over again of late years, by a class 

 of men who claim to be the only true interpreters of Nature, that we 

 know nothing but matter and the laws of matter, and that force is 

 a mere fiction of the imagination. May it not be affirmed, on the 

 other hand, that, while our notion of matter is a conception of the 

 intellect, force is that of which we have the most direct perhaps 

 even the only direct cognizance ? As I have already shown you, the 

 knowledge of resistance and of weight which we gain through our 

 tactile sense is derived from our own perception of exertion ; and in 

 vision, as in hearing, it is the force with which the undulations strike 

 the sensitive surface that affects our consciousness with sights or 

 sounds. True it is that in our visual and auditory sensations we do 

 not, as in our tactile, directly cognosce the force which produces 

 them ; but the Physicist has no difficulty in making sensible to us, 

 indirectly, the undulations by which sound is propagated, and in 

 proving to our intellect that the force concerned in the transmission 

 of light is really enormous. 



It seems strange that those who make the loudest appeal to experi- 

 ence as the basis of all knowledge, should thus disregard the most con- 

 stant, the most fundamental, the most direct of all experiences ; as to 

 which the common-sense of mankind affords a guiding light much 

 clearer than any that can be seen through the dust of philosophical 

 discussion. For, as Sir John Herschel most truly remarked, the 

 universal consciousness of mankind is as much in accord in regard to 

 the existence of a real and intimate connection between cause and 

 effect as it is in regard to the existence of an external world ; and that 

 consciousness arises to every one out of his own sense of personal 

 exertion in the origination of changes by his individual agency. 



Now, while fully accepting the logical definition of cause as the 

 " antecedent or concurrence of antecedents on which the effect is in- 

 variably and unconditionally consequent," we can always single out 

 one dynamical antecedent the power which does the work from the 

 aggregate of material conditions under which that power may be dis- 

 tributed and applied. ISTo doubt the term "cause" is very loosely 



