“Rational argument can be conducted with some prospect of success only so long as the emotionality of a given situation does not exceed a critical degree.”

“Even a happy life cannot be without a measure of darkness, and the word happy would lose its meaning if it were not balanced by sadness.”

“Mistakes are, after all, the foundations of truth, and if a man does not know what a thing is, it is at least an increase in knowledge if he knows what it is not. ”