“My fellow Americans, I know that at a time of upheaval overseas -- when the news is filled with conflict and change -- it can be tempting to turn away from the world. And as I’ve said before, our strength abroad is anchored in our strength here at home. That must always be our North Star -- the ability of our people to reach their potential, to make wise choices with our resources, to enlarge the prosperity that serves as a wellspring for our power, and to live the values that we hold so dear.”

1963, Remarks Prepared for Delivery at the Trade Mart in Dallas
Context: We in this country, in this generation, are — by destiny rather than choice — the watchmen on the walls of world freedom. We ask, therefore, that we may be worthy of our power and responsibility, that we may exercise our strength with wisdom and restraint, and that we may achieve in our time and for all time the ancient vision of "peace on earth, good will toward men". That must always be our goal, and the righteousness of our cause must always underlie our strength. For as was written long ago: "except the Lord keep the city, the watchman waketh but in vain."

Sabhal Mòr Ostaig Lecture (December 19, 2007)

1960s, October surprise speech (1968)

Source: Clockwork Angel

1960, Speech at East Los Angeles College Stadium, Los Angeles, California

Part I : Ambiguity and Freedom
The Ethics of Ambiguity (1947)
Variant: Let us try to assume our fundamental ambiguity. It is in the knowledge of the genuine conditions of our life that we must draw our strength to live and our reason for acting
Context: In spite of so many stubborn lies, at every moment, at every opportunity, the truth comes to light, the truth of life and death, of my solitude and my bond with the world, of my freedom and my servitude, of the insignificance and the sovereign importance of each man and all men. There was Stalingrad and there was Buchenwald, and neither of the two wipes out the other. Since we do not succeed in fleeing it, let us therefore try to look the truth in the face. Let us try to assume our fundamental ambiguity. It is in the knowledge of the genuine conditions of our life that we must draw our strength to live and our reason for acting [C'est dans la connaissance des conditions authentiques de notre vie qu'il nous faut puiser la force de vivre et des raisons d'agir].

Introduction
The Life of Poetry (1949)
Context: In time of crisis, we summon up our strength.
Then, if we are lucky, we are able to call every resource, every forgotten image that can leap to our quickening, every memory that can make us know our power. And this luck is more than it seems to be: it depends on the long preparation of the self to be used.
In time of the crises of the spirit, we are aware of all our need, our need for each other and our need for our selves. We call up, with all the strength of summoning we have, our fullness.

2009, A New Beginning (June 2009)

2000s, 2009, Farewell speech to the nation (January 2009)