MAN AS THE INTERPRETER OF NATURE. 693 



career left its imperishable impress on the art it enriched? But who 

 would be bold enough to affirm that an infant Mozart could be born 

 among a tribe whose only musical instrument is a tom-tom, whose 

 only song is a monotonous chant ? 



Again, by tracing the gradual genesis of some of those ideas which 

 we now accept as "self-evident" such, for example, as that of the 

 " Uniformity of Nature " we are able to recognize them as the expres- 

 sions of certain intellectual tendencies, which have progressively aug- 

 mented in force in successive generations, and now manifest them- 

 selves as mental instincts that penetrate and direct our ordinary 

 course of thought. Such instincts constitute a precious heritage, 

 which has been transmitted to us with ever-increasing value through 

 the long succession of preceding generations ; and which it is for us to 

 transmit to those who shall come after us, with all that further in- 

 crease which our higher culture and wider range of knowledge can 

 impart. 



And now, having studied the working action of the human intellect 

 in the scientific interpretation of Nature, we shall examine the general 

 character of its products ; and the first of these with which w T e shall 

 deal is our conception of matter and of its relation to force. 



The psychologist of the present day views matter entirely through 

 the light of his own consciousness : his idea of matter in the abstract 

 being that it is a " something " which has a permanent power of excit- 

 ing sensations, his idea of any " property " of matter being the mental 

 representation of some kind of sensory impression he has received from 

 it ; and his idea of any particular kind of matter being the representa- 

 tion of the whole aggregate of the sense-perceptions which its presence 

 has called up in his mind. Thus, when I press my hand against this 

 table, I recognize its unyieldingness through the conjoint medium of 

 my sense of toiich, my muscular sense, and my mental sense of effort, 

 to which it will be convenient to give the general designation of the 

 tactile sense ; and I attribute to that table a hardness which resists the 

 effort I make to press my hand into its substance, while I also recog- 

 nize the fact that the force I have employed is not sufficient to move 

 its mass. But I press my hand against a lump of dough, and, finding 

 that its substance yields under my pressure, I call it soft. Or, again, 

 I press my hand against this desk, and I find that, although I do not 

 thereby change its form, I change its place ; and so I get the tactile 

 idea of motion. Again, by the impressions received through the same 

 sensorial apparatus, when I lift this book in my hand, I am led to at- 

 tach to it the notion of weight or ponderosity ; and, by lifting different 

 solids of about the same size, I am enabled, by the different degrees of 

 exertion I find myself obliged to make in order to sustain them, to dis- 

 tinguish some of them as light, and others as heavy. Through the 

 medium of another set of sense-perceptions, which some regard as 

 belonging to a different category, we distinguish between bodies that 



