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

That, in the explanation of phenomena, we must proceed as if the field of inquiry had neither limits in space nor commencement in time; that we must be satisfied with the teaching of experience in reference to the material of which the world is posed; that we must not look for any other mode of the origination of events than that which is determined by the unalterable laws of nature; and finally, that we not employ the hypothesis of a cause distinct from the world to account for a phenomenon or for the world itself--are principles for the extension of speculative philosophy, and the discovery of the true sources of the principles of morals, which, however little conformed to in the present day, are undoubtedly correct.