LAWS OF NATURE. 355 



2. In thus attempting to ascertain the general order of 

 nature by ascertaining the particular order of the occurrence 

 of each one of the phenomena of nature, the most scientific 

 proceeding can be no more than an improved form of that 

 which was primitively pursued by the human understanding, 

 while undirected by science. When mankind first formed the 

 idea of studying phenomena according to a stricter and surer 

 method than that which they had in the first instance spon- 

 taneously adopted, they did not, conformably to the well- 

 meant but impracticable precept of Descartes, set out from 

 the supposition that nothing had been already ascertained. 

 Many of the uniformities existing among phenomena are so 

 constant, and so open to observation, as to force themselves 

 upon involuntary recognition. Some facts are so perpetually 

 and familiarly accompanied by certain others, that mankind 

 learnt, as children learn, to expect the one where they found 

 the other, long before they knew how to put their expectation 

 into words by asserting, in a proposition, the existence of a 

 connexion between those phenomena. No science was needed 

 to teach that food nourishes, that water drowns, or quenches 

 thirst, that the sun gives light and heat, that bodies fall to 

 the ground. The first scientific inquirers assumed these and 

 the like as known truths, and set out from them to discover 

 others which were unknown : nor were they wrong in so doing, 

 subject, however, as they afterwards began to see, to an ulte- 

 rior revision of these spontaneous generalizations themselves, 

 when the progress of knowledge pointed out limits to them, 

 or showed their truth to be contingent on some circumstance 

 not originally attended to. It will appear, I think, from 

 the subsequent part of our inquiry, that there is no logical 

 fallacy in this mode of proceeding ; but we may see already 

 that any other mode is rigorously impracticable : since it is 

 impossible to frame any scientific method of induction, or 

 test of the correctness of inductions, unless on the hypothesis 

 that some inductions deserving of reliance have been already 

 made. 



Let us revert, for instance, to one of our former illustra- 

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