There is nothing costs less than civility. [ Cervantes ]

Civility costs nothing, and buys everything. [ M. Wortley Montagu ]

Wisdom picks friends; civility plays the rest.
A toy shunn'd cleanly passeth with the best. [ George Herbert ]

One outward civility is current pay for another. [ Proverb ]

Mouth civility is no great pains, but may turn to good account. [ Proverb ]

Poverty is the test of civility and the touchstone of friendship. [ Hazlitt ]

Civility is a desire to receive civility, and to be accounted well bred. [ La Rochefoucauld ]

Familiarity is a suspension of almost all the laws of civility which libertinism has introduced into society under the notion of ease. [ La Roche ]

Authors have a greater right than any copyright, though it is generally unacknowledged or disregarded. They have a right to the reader's civility. There are favorable hours for reading a book, as for writing it, and to these the author has a claim. Yet many people think that when they buy a book, they buy with it the right to abuse the author. [ Henry Wadsworth Longfellow ]