Courtesy is mainly a manifestation of self-restraint.
Politeness and civilization are the golden keys to our coexistence.
Politeness costs nothing, but it's worth more than anything.
Knowledge makes people elegant, while communication makes people perfect.
Etiquette and courtesy are letters of recommendation to all sides.
Doctors are the cream of our civilized world.
Civilization is not spiritual in the daytime and spiritual uncivilization in the evening.