222 DISCOURSE ON THE STUDY 



semblage of effects, to find the causes. The principles 

 on which this enquiry relies are those which constitute 

 the relation of cause and effect, as it exists with 

 reference to our minds ; and their rules and mode 

 of application have been attempted to be sketched 

 out, (though in far less detail than the intrinsic 

 interest of the subject, both in a logical and prac- 

 tical point of view, would demand,) in the fore- 

 going pages. It remains now to bring together, in a 

 summary statement, the results of the general ex- 

 amination of nature, so far as it has been prosecuted 

 to the discovery of natural agents, and the mode in 

 which they act. 



(233.) The first great agent which the analysis 

 of natural phenomena offers to our consideration, 

 more frequently and prominently than any other, is 

 force. Its effects are either, 1st, to counteract the 

 exertion of opposing force, and thereby to maintain 

 equilibrium ; or, 2dly, to produce motion in matter. 



(234.) Matter, or that, whatever it be, of which 

 all the objects in nature which manifest themselves 

 directly to our senses consist, presents us with two 

 general qualities, which at first sight appear to stand 

 in contradiction to each other activity and inertness. 

 Its activity is proved by its power of spontaneously 

 setting other matter in motion, and of itself obeying 

 their mutual impulse, and moving under the influence 

 of its own and other force ; inertness, in refusing to 

 move unless obliged to do so by a force impressed 

 externally, or mutually exerted between itself and 

 other matter, and by persisting in its state of motion 

 or rest unless disturbed by some external cause. 

 Yet in reality this contradiction is only apparent. 

 Force being the cause, and motion the effect pro- 



