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

I know no investigations more necessary for a full insight into the nature of the faculty which we call understanding, and at the same time for the determination of the rules and limits of its use, than those undertaken in the second chapter of the "Transcendental Analytic," under the title of "Deduction of the Pure Conceptions of the Understanding"; and they have also cost me by far the greatest labour--labour which, I hope, will not remain uncompensated.