ON THE NOTION OF CAUSE 225 



for a person's death causes a certain act, because it is 

 believed that that act will cause the person's death ; or 

 more accurately, the desire and the belief jointly cause 

 the act. Brutus desires that Caesar should be dead, and 

 believes that he will be dead if he is stabbed ; Brutus 

 therefore stabs him, and the stab causes Caesar's death, 

 as Brutus expected it would. Every act which realises 

 a purpose involves two causal steps in this way : C is 

 desired, and it is believed (truly if the purpose is achieved) 

 that B will cause C ; the desire and the belief together 

 cause B, which in turn causes C. Thus we have first A, 

 which is a desire for C and a belief that B (an act) will 

 cause C ; then we have B, the act caused by A, and 

 believed to be a cause of C ; then, if the belief was 

 correct, we have C, caused by B, and if the belief was 

 incorrect we have disappointment. Regarded purely 

 scientifically, this series A, B, C may equally well be 

 considered in the inverse order, as they would be at a 

 coroner's inquest. But from the point of view of Brutus, 

 the desire, which comes at the beginning, is what makes 

 the whole series interesting. We feel that if his desires 

 had been different, the effects which he in fact produced 

 would not have occurred. This is true, and gives him 

 a sense of power and freedom. It is equally true that 

 if the effects had not occurred, his desires would have 

 been different, since being what they were the effects 

 did occur. Thus the desires are determined by their 

 consequences just as much as the consequences by the 

 desires ; but as we cannot (in general) know in advance 

 the consequences of our desires without knowing our 

 desires, this form of inference is uninteresting as applied 

 to our own acts, though quite vital as applied to those 

 of others. 



A cause, considered scientifically, has none of that 



IS 



