Frank J. Wilstach, comp. A Dictionary of Similes. 1916.
Manners
Fine manners are like personal beauty,—a letter of credit everywhere.
—C. A. Bartol
Manners … Like a great rough diamond, it may do very well in a closet by way of curiosity, and also for its intrinsic value.
—Earl of Chesterfield
Manners, like fashions, still from courts descend,
And what the great begin, the vulgar end.
—Paul Whitehead