CHAP. I.] THE STAETING-POINT. 9 



words, and that the same word can be employed twice with 

 the same meaning, as also that he is the same person when 

 he ends a sentence as he was when he began it, he cannot 

 carry on even a rational monologue ; and if he really doubts 

 as to whether an opponent has substantially the same powers 

 of understanding and expression as he has himself no con 

 troversy can be reasonably undertaken. If our life may be 

 a dream within a dream, if we may not be supremely sure 

 that a thing cannot both le and not le at the same time and 

 in the same sense then thinking may indeed be affirmed to 

 be an idle waste of thought, were it not impossible to affirm 

 that anything is or is not anything, and as impossible to 

 affirm such impossibility. Such scepticism is, of course, as 

 practically impossible as it is absurd. Doubt may be 

 expressed as to the validity of all intellectual acts, but any 

 attempt to defend the sceptical position thereby actually 

 demonstrates a belief in such validity on the very part of 

 him who would verbally deny it. Familiar as will be these 

 reflections, it seems nevertheless desirable to dwell upon 

 them, that their truth may be clearly brought home. For 

 it follows (and this is an important consequence) that if 

 any premisses logically and necessarily result in such absolute 

 scepticism they may be disproved by a redudio ad alsurdum. 

 This is so because absolute scepticism cannot be even 

 believed (since to believe it would be ipso facto to deny it 

 by asserting the certainty of uncertainty), and is absurd, and 

 no reasoning which necessarily leads to absurdity can be 

 valid in the eyes of those who, not being themselves absolute 

 sceptics, are certain that utter absurdity and absolute truth 

 are not one and the same. 



The second preliminary assertion is as follows : 



II. Propositions are not to le defended which cannot be even 



conceived to le seriously entertained ly some one. 

 This assertion serves to discriminate between real and 

 verbal doubt. There is, of course, nothing which The second 



,. i 11 rni i proposition. 



cannot be called m question verbally. I he exist- 



