186 DISCOURSE ON THE STUDY 



offers itself spontaneously, and thus furnish ad- 

 vanced points in our enquiries ; and when we start 

 from these, already " a thousand steps are lost." 



(195.) A fine example of a collective instance is 

 that of the system of Jupiter or Saturn with its 

 satellites. We have here, in miniature, and seen 

 at one view, a system similar to that of the planets 

 about the sun ; of which, from the circumstance of 

 our being involved in it, and unfavourably situated 

 for seeing it otherwise than in detail, we are in- 

 capacitated from forming a general idea but by 

 slow progressive efforts of reason. Accordingly, the 

 contemplation of the circumjovial planets (as they 

 were called) most materially assisted in securing 

 the admission of the Copernican system. 



(196.) Of " Crucial instances" we have also al- 

 ready spoken, as affording the readiest and securest 

 means of eliminating extraneous causes, and decid- 

 ing between rival hypotheses. Owing to the dis- 

 position of the mind to form hypotheses, and to 

 prejudge cases, it constantly happens that, among 

 all the possible suppositions which may occui, two 

 or three principal ones occupy us, to the exclusion 

 of the rest ; or it may be that, if we have been less 

 precipitate, out of a great multitude rejected for 

 obvious inapplicability to some one or other case, 

 two or three of better claims remain for decision ; 

 and this such instances enable us to do. One of 

 the instances cited by Bacon in illustration of his 

 crucial class is very remarkable, being neither more 

 nor less than the proposal of a direct experiment to 

 determine whether the tendency of heavy bodies 

 downwards is a result of some peculiar mechanism 



