I think; therfore I am. - René Descartes

But this could not be the case with-the idea of a nature more perfect than myself; for to receive it from nothing was a thing manifestly impossible; and, because it is not less repugnant that the more perfect should be an effect of, and dependence on the less perfect, than that something should proceed from nothing, it was equally impossible that I could hold it from myself:

y que dice que nada hay en el entendimiento que no haya estado antes en el sentido

I am accustomed to sleep and in my dreams to imagine the same things that lunatics imagine when awake.