10 THE CREED OF SCIENCE, RELIGIOUS AND MORAL. 



these particles came together, impinged on one another, 

 or gathered' into groups, this potential energy was 

 gradually transformed into the energy of heat, and into 

 that of visible motion. We may thus imagine the cooling 

 and (except under very strict conditions of original dis- 

 tribution) necessarily revolving matter, in course of time 

 to have thrown off certain parts of itself, which would 

 thereafter form satellites m or planetary attendants, while 

 the central mass would form the sun." * 



Now, if this be the development hypothesis of Kant 

 and Laplace, as we are expressly told it is, it must be 

 allowed that most of the difficulties which beset the more 

 audacious . presentments of it are avoided. But also, it 

 must be said, with this more guarded and general state- 

 ment of it, nearly all the grandeur of the hypothesis 

 vanishes. With the contracting spheres and the mighty 

 rings of vapour suppressed, which closed together and 

 became worlds, all the charm and attractiveness is gone. 

 That, however, should not signify in a matter that 

 respects only scientific accuracy. True ; but also with 

 the removal of the rings and the sphere of vapour, the 

 hypothesis itself is gone. There is nothing remaining 

 but a mass of matter which threw off parts of itself in 

 its revolution a different, if a safer, theory. Nor is it 

 wholly satisfactory either. For unless the parts were pro- 

 pelled in a skilful manner that has not been described, 

 they must have either fallen back again or travelled into 

 space, to return no more ; and why neither of these acci- 

 dents, antecedently possible, did actually happen, we are 

 left to surmise. 



This last theory has, however, been presented by 

 Sir W. Thomson, its real originator, from a much more 



* The Unseen Universe, p. 164, Fifth Ed. 



