Click on the phrases to see them in context. The original texts by Immanuel Kant and David Hume are available from the Gutenberg Projet.

As, during these labours, I have advanced pretty far in years this month I reach my sixty-fourth year--it will be necessary for me to economize time, if I am to carry out my plan of elaborating the metaphysics of nature as well as of morals, in confirmation of the correctness of the principles established in this Critique of Pure Reason, both speculative and practical; and I must, therefore, leave the task of clearing up the obscurities of the present work--inevitable, perhaps, at the outset--as well as, the defence of the whole, to those deserving men, who have made my system their own.