234 Force, Energy, and Will 



another force, or else force moves itself, and thus we have 

 the conception of a new substance Avith active powers 

 gratuitously introduced in order to explain the activities of 

 the two bodies (the balls) — the moving and the moved. 



If by ' force ' and its ' persistence ' be meant ' cause,' and 

 if I am challenged to admit the 'persistence of cause' as 

 a necessary article of my philosophical creed, I answer by 

 as readily denying the real existence of the abstraction 

 'cause' as the existence of the abstraction 'force.' But 

 because the existence of an abstraction be denied, it by 

 no means follows that the existence of an objectively real, 

 persistent cause should be also denied. Indeed, just as 

 reason seems to tell me that bodies with active powers exist 

 — concrete existences, with very real and very special poAvers 

 — so reason seems to tell me that one concrete cause exists, 

 the most real of realities, the most powerful of powers — God. 



But the title of this paper refers not to ' force ' only, but 

 also to 'energy,' and it does so because of the change of 

 language which has recently taken place. Physicists have 

 ceased, or are ceasing, to speak of the persistence and trans- 

 formation of force, : we hear now only of the persistence and 

 transformation of energy. In what sense, however, is the 

 word ' energy ' really used ? In every known activity of 

 any body, e.g., in heat, we have manifested (1) the sensible 

 perception by which it becomes known to our senses — in 

 the case supposed the sensation of heat ; and (2) the intel- 

 lectual perception of an objective power or activity of a 

 definite kind in the body which acts upon our organism. 

 Now, if the word 'energy' is used in the sense of 'bodily 

 activity,' there is nothing to be said against it save that 

 it is a somewhat obscure and ambiguous expression. More- 

 over, though the quantitative equivalence between successive 

 activities is indeed a great discovery reflecting high honour 

 on the discoverers, yet the transformation of energy in the- 



