ISO THE GRAMMAR OF SCIENCE 



which in practical hfe we should term certainty), we must 

 at the same time remember that because a proposition 

 has not yet been proved, we have no right to infer that 

 its converse must be true. It is not a case of balancing 

 contradictory evidence, for not a single valid argument is 

 to be found in the whole range of human experience for 

 inferring a first or last cause. There may be a beginning 

 and an end to life on our planet ; we may term these, if 

 we please, a " first and a last catastrophe." But among 

 the myriad planetary systems we see on a clear night 

 there surely must be myriad planets which have reached 

 our own stage of development, and teem, or have teemed, 

 with human life. The first and last catastrophe must 

 have occurred a myriad times, and were we able to watch 

 through long thousands of years the changing brilliancy 

 of stars, the first and last catastrophe would appear to us 

 not as a first and last cause, but as much a routine of per- 

 ceptions as the birth and death of individual men. 



SUMMARY 



1. Cause is scientifically used to denote an antecedent stage in a routine 

 of perceptions. In this sense force as a cause is meaningless. First cause is 

 only a limit, permanent or temporary, to knowledge. No instance, certainly 

 not will, occurs in our experience of an arbitrary first cause in the popular 

 sense of the word. 



2. There is no inherent necessity in the routine of perceptions, but the 

 permanent existence of rational beings necessitates a routine of perceptions ; 

 with the cessation of routine ceases the possibility of a thinking being. The 

 only necessity we are acquainted with exists in the sphere of conceptions ; 

 possibly routine in perceptions is due to the constitution of the perceptive 

 faculty. 



3. Proof in the field of perceptions is the demonstration of overwhelming 

 probability. Logically we ought to use the word kuoiv only of conceptions, 

 and reserve the word believe for perceptions. " I know that the angle at the 

 circumference on any diameter of a circle is right," but "I beheve that the 

 sun will rise to-morrow." The proof that for no finite future a breach of 

 routine will occur depends upon the solid experience that where we are ignorant, 

 there statistically all constitutions of the unknown are found to be equally 

 probable. 



