40 DESCARTES. 



quently it is at least as certain that God, who is this 

 Perfect Being, is, or exists, as any. demonstration of 

 Geometry can be. 



But the reason which leads many to persuade 

 themselves that there is a difficulty in knowing this 

 truth, and even also in knowing what their mind 

 really is, is that they never raise their thoughts 

 above sensible objects, and are so accustomed to 

 consider nothing except by way of imagination, 

 which is a mode of thinking limited to material 

 objects, that all that is not imaginable seems to 

 them not intelligible. The truth of this is suffi 

 ciently manifest from the single circumstance, that 

 the philosophers of the Schools accept as a maxim 

 that there is nothing in the Understanding which 

 was not previously in the Senses, in which however 

 it is certain that the ideas of God and of the soul 

 have never been; and it appears to me that they 

 who make use of their imagination to comprehend 

 these ideas do exactly the same thing as if, in order 

 to hear sounds or smell odours, they strove to avail 

 themselves of their eyes; unless indeed that there is 

 this difference, that the sense of sight does not 

 afford us an inferior assurance to those of smell or 

 hearing; in place of which, neither our imagination 

 nor our senses can give us assurance of anything 

 unless our Understanding intervene. 



Finally, if there be still persons who are not suffi 

 ciently persuaded of the existence of God and of the 

 soul, by the reasons I have adduced, I am desirous 

 that they should know that all the other proposi 

 tions, of the truth of which they deem themselves 



