ON THE STUDY OF PHYSICS 307 



brotherhood in Nature are organically united, and finds 

 the detection of such analogies a source of perpetual de- 

 light. To enlist pleasure on the side of intellectual per- 

 formance is a point of the utmost importance; for the ex- 

 ercise of the mind, like that of the body, depends for its 

 value upon the spirit in which it is accomplished. Every 

 physician knows that something more than mere mechan- 

 ical motion is comprehended under the idea of healthful 

 exercise — that, indeed, being most healthful which makes 

 Tis forget all ulterior ends in the mere enjoyment of it. 

 What, for example, could be substituted for the action of 

 the playground, where the boy plays for the mere love 

 of playing, and without reference to physiological laws; 

 while kindly Nature accomplishes her ends unconsciously, 

 and makes his very indifference beneficial to him. You 

 may have more systematic motions, you may devise means 

 for the more perfect traction of each particular muscle, 

 but you cannot create the joy and gladness of the game, 

 and where these are absent, the charm and the health of 

 the exercise are gone. The case is similar with the edu- 

 cation of the mind. 



The study of Physics, as already intimated, consists of 

 two processes, which are complementary to each other— 

 the tracing of facts to their causes, and the logical ad 

 vance from the cause to the fact. In the former process 

 called induction^ certain moral qualities come into play, 

 The first condition of success is patient industry, an hon 

 est receptivity, and a willingness to abandon all precon 

 ceived notions, however cherished, if they be found to 

 contradict the truth. Believe me, a self-renunciation 

 which has something lofty in it, and of which the 

 world never hears, is often enacted in the private ex- 



