I think America has more than enough maturity and intelligence to start exercising its world leadership responsibly.

Immaturity is the incapacity to use one's intelligence without the guidance of another.

Maturity - among other things the unclouded happiness of the child at play who takes it for granted that he is at one with his play-mates.

How often I have found that we grow to maturity not by doing what we like but by doing what we should. How true it is that not every 'should' is a compulsion and not every 'like' is a high morality and true freedom.

The other day the President said I know you've had some rough times and I want to do something that will show the nation what faith that I have in you in your maturity and sense of responsibility. He paused then said would you like a puppy?

The possibility of a scientific treatment of history means a wider experience a greater maturity of practical reason and finally a fuller realization of certain basic ideas regarding the nature of life and time.

Knowledge comes but wisdom lingers. It may not be difficult to store up in the mind a vast quantity of facts within a comparatively short time but the ability to form judgments requires the severe discipline of hard work and the tempering heat of experience and maturity.

What I look forward to is continued immaturity followed by death.

I don't think people change. I think they definitely mature. But I think the essence of what I am today is the same as when I was five years old. It's just maturity. I've become a healthier fuller expression of that essence.

Another unsettling element in modern art is that common symptom of immaturity the dread of doing what has been done before.