No More Learning

It is
absolutely impossible, however, to know the existence of this Being
from mere concepts, because every existential proposition, that is,
every proposition that affirms the existence of a being of which I
frame a concept, is a           proposition, that is, one by which I
go beyond that conception and affirm of it more than was thought in
the conception itself; namely, that this concept in the
understanding has an object corresponding to it outside the
understanding, and this it is obviously impossible to elicit by any
reasoning.