In philosophy it is the view that the promotion of individual and collective human excellence is one of the main factors which should be taken into account when judging the political and social worth of a society.
Dr. Mark Alan Walker argues that perfectionism is or should be the ethical imperative behind transhumanism in his essay Absolute Versus Human Perfectionism.
In psychology perfectionism is an ego self-defense mechanism: it is a form of procrastination when it is used to postpone tasks ("I can't do anything on this until I know the perfect thing to do so that I won't make any mistakes"), and a form of self-deprecation when it is used to excuse poor performance or to seek sympathy and affirmation from other people ("I must be perfect, but I keep falling short of my own goals, why am I so terrible?").
A variation on a quoted adage of US General George Patton is: Do not let the perfect be the enemy of the good.