The deepest principle in human nature is the craving to be appreciated.

Don't complain about the snow on your neighbor's roof when your own doorstep is unclean.

When dealing with people, let us remember we are not dealing with creatures of logic.  We are dealing with creatures of emotion, creatures bristling with prejudices and motivated by pride and vanity.

There is nothing else that so kills the ambitions of a person as criticisms from superiors.  I never criticize anyone...If I like anything, I am hearty in my approbation and lavish in my praise.

It is not what you say that matters but the manner in which you say it; there lies the secret of the ages.