308 SENSATION AND THE SENSIFEROUS ORGANS 



pellate : " The upshot of all this long disquisition is 

 that we are profoundly ignorant. We knew that to 

 begin with, and you have merely furnished another 

 example of the emptiness and uselessness of 

 metaphysics." But I venture to reply, Pardon me, 

 you were ignorant, but you did not know it. On 

 the contrary, you thought you knew a great deal, 

 and were quite satisfied with the particularly absurd 

 metaphysical notions which you were pleased to 

 call the teachings of common sense. You thought 

 that your sensations were properties of external 

 things, and had an existence outside of yourself. 

 You thought that you knew more about material 

 than you do about immaterial existences. And if, 

 as a wise man has assured us, the knowledge of 

 what we don't know is the next best thing to the 

 knowledge of what we do know, this brief excursion 

 into the province of philosophy has been highly 

 profitable. 



Of all the dangerous mental habits, that which 

 schoolboys call " cocksureness " is probably the 

 most perilous; and the inestimable value of 

 metaphysical discipline is that it furnishes an 

 effectual counterpoise to this evil proclivity. 

 Whoso has mastered the elements of philosophy 

 knows that the attribute of unquestionable cer- 

 tainty appertains only to the existence of a state 

 of consciousness so long as it exists ; all other 

 beliefs ar& mere probabilities of a higher or lower 

 order. Sound metaphysic is an amulet which 



