...nothing is so improving to the temper as the study of the beauties, either of poetry, eloquence, music, or painting. They give a certain elegance of sentiment to which the rest of mankind are strangers. The emotions which they excite are soft and tender. They draw off the mind from the hurry of business and interest; cherish reflection; dispose to tranquillity; and produce an agreeable melancholy, which, of all dispositions of the mind, is the best suited to love and friendship.
David Hume, "Of the Delicacy of Taste and Passion". 'Melancholy', I take it, is being used in the old-fashioned sense of that temperamental humor most conducive to reflection.
Of course, Hume immediately goes on to argue that the second reason delicacy of taste is favorable to love and friendship is that it makes it difficult to find people to love and be friends with. This seems to anticipate some Romantic conceptions of love and friendship; that portrayed in Mary Shelley's Frankenstein, for instance.