/ 



170 Life and Matter [chap. ix. 



shall shatter a rock. Granted : but the 

 work-concomitants of that energy are all 

 familiar, and equally present whether it be 

 arranged so as to produce any predetermined 

 effect or not. The opening of the throttle- 

 valve for instance demands just the same 

 exertion, and results in just the same imper- 

 ceptible transformation of fully-accounted-for 

 energy, whether it be used to start a train in 

 accordance with a time-table and the guard's 

 whistle, or whether it be pushed over, as if 

 by the wind, at random. The shouting of 

 an order to a troop demands vocal energy 

 and produces its due equivalent of sound ; 

 but the intelligibility of the order is some- 

 thing superadded, and its result may be to 

 make not sound or heat alone, but History. 



Energy must be available for the perfor- 

 mance of any physical operation, but the 

 energy is independent of the determination 

 or arrangement. Guidance and control are 

 not forms of energy, nor need they be 

 themselves phantom modes of force : their 

 superposition upon the scheme of Physics 



