Meditations - pg. xxxvi

It is enough for St. Augustine to know this God and his soul. But Descartes is not satisfied; he needs a Physics, a knowledge of the real world in order to be able to act and to direct himself in life, a knowledge that will make man master and possessor of nature and will give him the power to order and freely determine his very existence. And it is in order to put this science, whose 'foundations' he has discovered, on a firm and secure basis that he develops his metaphysics and turns his steps towards God. Here as elsewhere the Cartesian search is the search for the assurance of truth. Here as elsewhere the Cartesian way is the way of insight and freedom.