SCIENCE 369 



" vertebrate," if we did not know that all vertebrate 

 animals have a spinal column. 



If we had no certain knowledge of any fact, all our 

 processes of reasoning would, as it were, remained sus- 

 pended in the air and have no relation with any real 

 thing whatever. Now our knowledge of facts may vary 

 greatly. Some men know an enormously greater numt 

 ber of them than others do. There is, however, one fac- 

 which everybody knows with the most absolute certainty, 

 and that is the fact that he himself exists.* This know- 

 ledge lies at the foundation of our whole intellectual 

 life.f 



The supreme and absolute certainty which each of 

 us may have with respect to this fundamental fact 

 would seem to be indisputable ; and yet there are some 

 persons who dispute it and affirm that though we may, 

 and do, have absolute certainty about any state of feeling 

 present at the moment, no continuous or substantial 

 self-existence can certainly be known to us. 



Now, we have already affirmed it j absurd to suppose 

 our consciousness is made up of an aggregate of states, 

 and that we have no continuous intellectual activity. It 

 is now time to show how the delusion that we cannot be 

 supremely certain of our own continuous existence has 

 arisen. Our primary, direct consciousness at any 

 moment, is neither a consciousness of a state (of a 

 '* feeling ") nor of our continuous existence, but a per- 

 ception and consciousness of our doing something (e.g., 

 reading this book) or having something done to us (e.g.. 

 being supported in a chair). We have, indeed, all the 

 time some vague perception of "self -existence" and 



* See ante, pp. 258 and 270. t See ante, p. 258. 



$ See ante, loc. cit. 



2 A 



