66 HUME ! 



certainty are merely more or less probable 

 inferences. Berkeley and Locke, each in his 

 way, applied philosophical criticism in other 

 directions ; but they always, at any rate profess- 

 edly, followed the Cartesian maxim of admitting 

 no propositions to be true but such as are clear, 

 distinct, and evident, even while their arguments 

 stripped off many a layer of hypothetical assump- 

 tion, which their great predecessor had left un- 

 touched. No one has more clearly stated the 

 aims of the critical philosopher than Locke, in a 

 passage of the famous " Essay concerning Human 

 Understanding," which, perhaps, I ought to 

 assume to be well known to all English readers, 

 but which so probably is unknown to this full- 

 crammed and much-examined generation that I 

 venture to cite it : 



" If by this inquiry into the nature of the understanding I 

 can discover the powers thereof, how far they reach, to what 

 things they are in any degree proportionate, and where they 

 fail us, I suppose it may be of use to prevail with the busy 

 mind of man to be more cautious in meddling with things 

 exceeding his comprehension : to stop when it is at the utmost 

 extent of its tether ; and to sit down in quiet ignorance of 

 those things which, upon examination, are proved to be 

 beyond the reach of our capacities. We should not then, 

 perhaps, be so forward, out of an affectation of universal 

 knowledge, to raise questions and perplex ourselves and others 

 with disputes about things to which our understandings are 

 not suited, and of which we cannot frame in our minds any 

 clear and distinct perception, or whereof (as it has, perhaps, 

 too often happened) we have not any notion at all .... 

 Men may find matter sufficient to busy their heads and 



