David Hume,
Treatise of Human Nature/Book 3…
(1739)
“ When any virtuous motive or principle is common in human nature, a person, who feels his heart devoid of that motive, may hate himself upon that account, and may perform the action without the motive, from a certain sense of duty, in order to acquire by practice, that virtuous principle, or at least, to disguise to himself, as much as possible, his want of it. A man that really feels no gratitude in his temper, is still pleas'd to perform grateful actions, and thinks he has, by that means, fulfill'd his duty. ”
