I encourage courtesy. To accept nothing less than courtesy, and to give nothing less than courtesy. If we accept being talked to any kind of a way, then we are telling ourselves we are not quite worth the best. And if we have the effrontery to talk to anybody with less than courtesy, we tell ourselves and the world we are not very intelligent.
Man often becomes what he believes himself to be. If I keep on saying to myself that I cannot do a certain thing, it is possible that I may end by really becoming incapable of doing it. On the contrary, if I have the belief that I can do it, I shall surely acquire the capacity to do it even if I may not have it at the beginning.