After reading the selected chapters of Descartes Meditations ONE on First Philosophy, to what certainty does Descartes methodical doubt lead? How can Descartes know that he exists and that God exists? What is the nature of such a knowledge? Is there anything thing at all that you are so certain of that you could not possibly doubt it? In what sense is Descartes methodical doubt both a contribution to the theory of knowledge and a starting point for modern philosophy?