6 FINAL CAUSES. 



rise to different kinds of knowledge, each of 

 which requires to be investigated in a peculiar 

 mode and by a different process of reasoning. 

 The foundation of both these kinds of know- 

 ledge is, indeed, the same ; namely, the constant 

 uniformity which takes place in the succession 

 of events, and which, when traced in particular 

 classes of phenomena, constitutes what we me- 

 taphorically call the Lmvs of Nature. It is the 

 province of philosophy, strictly so called, to 

 discover the circumstances or laws which regu- 

 late this uniformity, and to arrange the observed 

 changes according to their invariable antece- 

 dents, or causes : the unknown links by which 

 these causes are connected with their respective 

 consequents, or effects, being denominated the 

 poivers of Nature. With reference to phenomena 

 which are purely mechanical, that is, to changes 

 which consist in the sensible motions of material 

 bodies, these powers are denominated forces ; 

 and the intensities, the operations, and the cha- 

 racters of these forces admit of exact definition, 

 according to the qualities of the corresponding 

 effects they produce. It is by pursuing the 

 method of philosophical induction, so well ex- 

 plained by Bacon, that the physical sciences, 

 which the misdirected efforts of former ages had 

 failed to advance, have, within the last two 

 centuries, been carried to a height of perfection 



