“Do what you know needs to be done.”

“You will never know what could have been done until you start doing what needs to be done.”

“Doing what needs to be done may not make you happy, but it will make you great.”

“You know what must be done.""No, I do not know what must be done. I do not routinely summon people from the grave and have them following me around!”

“The purpose of life is not to do what we want but what needs to be done.”

“Knowing yourself means knowing, first, what it is to be a person; secondly, knowing what it is to be the kind of person you are; and thirdly, knowing what it is to be the person you are and nobody else is. Knowing yourself means knowing what you can do; and since nobody knows what they can do until they try, The only clue to what man can do is what man has done. The value of history, then, is that it teaches us what man has done and thus what man is.”