Can we imagine ourselves sincerely convinced of the existence of a being, whose nature we know not; who is inaccessible to all our senses; whose attributes, we are assured, are incomprehensible to us? To persuade me that a being exists or can exist, I must be first told what that being is. To induce me to believe the existence or the possibility of such a being, it is necessary to tell me things concerning him that are not contradictory, and do not destroy one another. In short, to fully convince me of the existence of that being, it is necessary to tell me things that I can understand.