David Hume,
Treatise of Human Nature/Book 3…
(1739)
“ As conversation is a transcript of the mind as well as books, the same qualities, which render the one valuable, must give us an esteem for the other. This we shall consider afterwards. In the mean time it may be affirm'd in general, that all the merit a man may derive from his conversation (which, no doubt, may be very considerable) arises from nothing but the pleasure it conveys to those who are present. In this view, cleanliness is also to be regarded as a virtue; since it naturally renders us agreeable to others, and is a very considerable source of love and affection. ”
