r 177 J 



of which we can have at mod only a moral certainty; and 

 fometimes he denotes by it a mere conformity to pafl' ex- 

 perience, either of our own or of otliers, which is often 

 attended with phyfical or moral certainty, and often with bare 

 probability : thefe different fenfes he dexteroully fliifts and em- 

 ploys as befl fuits his purpofe. 



2*^. The radical error that pervades the whole of this.Kflay, 

 and is indeed the corner (lone on which his whole theory mud 

 reft, even if the equivocal ttfe of the term experience had been 

 avoided, confifts in afcribing the fame immutability to the 

 laws by which corporeal nature is governed, as to thofe which 

 are inherent in the nature of moral agents. Knowledge of the 

 former is conveyed to us chiefly by experience ; that of the latter 

 arifes partly from experience, but being homogeneous with, and 

 analogous to our own feelings, partly alfo from confcioufnefs : 

 the former are clearly difcerned to proceed from the power 

 and wifdom of the author of nature, which experience itfelf 

 fhews us not to require their abfolute immutability in all poffible 

 circumftances- Thus no law has ever been confidered lefs 

 mutable than that of the defcent of bodies when unfupported, yet 

 exceptions to it have at lalt occurred, not only through the now 

 well known, but hitherto inexplicable, powers of magnetifm 

 and eledricity, but alfo in the adherence of the hardeft poliflied 



Vol. VIII. ' Z bodies. 



