DISCOURSE ON METHOD. 35 



rejected as false all the reasonings I had hitherto 

 taken for demonstrations; and finally, when I con 

 sidered that the very same thoughts (presentations) 

 which we experience when awake may also be 

 experienced when we are asleep, while there is at 

 that time not one of them true, I supposed that all 

 the objects (presentations) that had ever entered 

 into my mind when awake, had in them no more 

 truth than the illusions of my dreams. But imme 

 diately upon this I observed that, whilst I thus 

 wished to think that all was false, it was absolutely 

 necessary that I, who thus thought, should be some- 

 what; and as I observed that this truth, / think, 

 hence I am, was so certain and of such evidence, that 

 no ground of doubt, however extravagant, could be 

 alleged by the Sceptics capable of shaking it, I con 

 cluded that I might, without scruple, accept it as the 

 first principle of the Philosophy of which I was in 

 search. 



In the next place, I attentively examined what I 

 was, and as I observed that I could suppose that I 

 had no body, and that there was no world nor any 

 place in which I might be; but that I could not 

 therefore suppose that I was not ; and that, on the 

 contrary, from the very circumstance that I thought 

 to doubt of the truth of other things, it most clearly 

 and certainly followed that I was; while, on the 

 other hand, if I had only ceased to think, although 

 all the other objects which I had ever imagined had 

 been in reality existent, I would have had no reason 

 to believe that I existed; I thence concluded that I 

 was a substance whose whole essence or nature 



