Click on the phrases to see them in context. The original texts by Immanuel Kant and David Hume are available from the Gutenberg Projet.
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If belief consisted only in a certain vivacity, conveyed from an original impression, it would decay by the length of the transition, and must at last be utterly extinguished: And vice versa, if belief on some occasions be not capable of such an extinction; it must be something different from that vivacity. In giving a reason, therefore, for the pleasure or uneasiness, we sufficiently explain the vice or virtue. It is impossible, therefore, that the character of natural and unnatural can ever, in any sense, mark the boundaries of vice and virtue.