Ambition is pitiless. Any merit that it cannot use it finds despicable.

...no matter how avid they themselves may be for praise and appreciation, people are often niggardly in giving it to others, however merited it is.

You must do the things you think you cannot do.

Justice cannot be for one side alone, but must be for both.

Friendship with ones self is all important, because without it one cannot be friends with anyone else in the world.

It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly; who errs and comes short again and again; because there is not effort without error and shortcomings; but who does actually strive to do the deed; who knows the great enthusiasm, the great devotion, who spends himself in a worthy cause, who at the best knows in the end the triumph of high achievement and who at the worst, if he fails, at least he fails while daring greatly. So that his place shall never be with those cold and timid souls who know neither victory nor defeat.