“We must work to provide the knowledge and the surroundings which can enlarge the possibilities of every citizen. The American covenant called on us to help show the way for the liberation of man. And that is today our goal. Thus, if as a nation there is much outside our control, as a people no stranger is outside our hope.”

Day of Affirmation Address (1966)
Context: The help and the leadership of South Africa or of the United States cannot be accepted if we, within our own country or in our relationships with others, deny individual integrity, human dignity, and the common humanity of man. If we would lead outside our borders, if we would help those who need our assistance, if we would meet our responsibilities to mankind, we must first, all of us, demolish the borders which history has erected between men within our own nations — barriers of race and religion, social class and ignorance.
Our answer is the world's hope; it is to rely on youth. The cruelties and the obstacles of this swiftly changing planet will not yield to obsolete dogmas and outworn slogans. It cannot be moved by those who cling to a present which is already dying, who prefer the illusion of security to the excitement and danger which comes with even the most peaceful progress. This world demands the qualities of youth: not a time of life but a state of mind, a temper of the will, a quality of the imagination, a predominance of courage over timidity, of the appetite for adventure over the love of ease.

As quoted in Joseph Telushkin's Rebbe: The Life and Teachings of Menachem M. Schneerson, the Most Influential Rabbi in Modern History

On the American public, as quoted in "The Awkward Conscience of a Nation" in The Daily Mirror (3 November 2003); also partly quoted in "The company they keep" by Michael Barone, in U.S.News & World Report (12 July 2004) http://www.usnews.com/usnews/opinion/articles/040712/12barone.htm
2004

Source: Happiness: A Guide to Developing Life's Most Important Skill

2010s, Farewell Speech (2017)

Source: Unspoken Sermons: Series I, II, III

1860s, Oration at Ravenna, Ohio (1865)
Context: In the great crisis of the war, God brought us face to face with the mighty truth, that we must lose our own freedom or grant it to the slave. In the extremity of our distress, we called upon the black man to help us save the Republic; and, amid the very thunders of battle, we made a covenant with him, sealed both with his blood and with ours, and witnessed by Jehovah, that, when the nation was redeemed, he should be free, and share with us its glories and its blessings. The Omniscient Witness will appear in judgment against us if we do not fulfill that covenant. Have we done it? Have we given freedom to the black man? What is freedom? Is it mere negation? Is it the bare privilege of not being chained, of not being bought and sold, branded and scourged? If this is all, then freedom is a bitter mockery, a cruel delusion, and it may well be questioned whether slavery were not better. But liberty is no negation. It is a substantial, tangible reality. It is the realization of those imperishable truths of the Declaration, 'that all men are created equal'; that the sanction of all just government is 'the consent of the governed.' Can these be realized until each man has a right to be heard on all matters relating to himself? The plain truth is, that each man knows his own interest best It has been said, 'If he is compelled to pay, if he may be compelled to fight, if he be required implicitly to obey, he should be legally entitled to be told what for; to have his consent asked, and his opinion counted at what it is worth. There ought to be no pariahs in a full-grown and civilized nation, no persons disqualified except through their own default.' I would not insult your intelligence by discussing so plain a truth, had not the passion and prejudice of this generation called in question the very axioms of the Declaration.

2000s, 2001, A Great People Has Been Moved to Defend a Great Nation (September 2001)

Source: Nationalism and Culture (1937), Ch. 1 "The Insufficiency of Economic Materialism"
Context: Every process which arises from our physical being and is related to it, is an event which lies outside of our volition. Every social process, however, arises from human intentions and human goal setting and occurs within the limits of our volition. Consequently, it is not subject to the concept of natural necessity. … We are here stating no prejudiced opinion, but merely an established fact. Every result of human purposiveness is of indisputable importance for man's social existence, but we should stop regarding social processes as deterministic manifestations of a necessary course of events. Such a view can only lead to the most erroneous conclusions and contribute to a fatal confusion in our understanding of historical events.
It is doubtless the task of the historian to trace the inner connection of historical events and to make clear their causes and effects, but he must not forget that these connections are of a sort quite different from those of natural physical events and must therefore have quite a different valuation.