“Family, clan, country, union of nations — each unit strives toward peace, toward betterment of life. Each unit of cooperation and communal life needs perfecting. No one can fix the limits of evolution. By this line of reasoning a worker becomes a creator. Let us not be frightened by the problems of creativeness. Let us find for science unencumbered paths. Thus, thought about perfectionment will be a sign of joy.”

Quote in a letter of Vincent to brother Theo van Gogh, from Etten (Netherlands), Spring, 1877; as quoted in Vincent van Gogh, edited by Alfred H. Barr; Museum of Modern Art, New York, 1935 https://www.moma.org/documents/moma_catalogue_1996_300061887.pdf, (letter 90), p. 7
1870s

Speech as Viceroy of India (1926), quoted in Birkenhead, Halifax (Hamish Hamilton, 1965), pp. 223-234
Viceroy of India

Nobel Peace Prize Acceptance Speech (2012)
Context: The peace of our world is indivisible. As long as negative forces are getting the better of positive forces anywhere, we are all at risk. It may be questioned whether all negative forces could ever be removed. The simple answer is: “No!” It is in human nature to contain both the positive and the negative. However, it is also within human capability to work to reinforce the positive and to minimize or neutralize the negative. Absolute peace in our world is an unattainable goal. But it is one towards which we must continue to journey, our eyes fixed on it as a traveller in a desert fixes his eyes on the one guiding star that will lead him to salvation. Even if we do not achieve perfect peace on earth, because perfect peace is not of this earth, common endeavours to gain peace will unite individuals and nations in trust and friendship and help to make our human community safer and kinder.

Understanding & Collaboration Between Religions (2006)

Let an observer B on the star estimate the distance and epoch of the nova outburst to be x<nowiki>'</nowiki> units of length and t<nowiki>'</nowiki> units of time, respectively. Then the Lorentz formulae, relating x<nowiki>'</nowiki> to t<nowiki>'</nowiki>, are<center><math>x' = \frac {x-vt}{\sqrt{1-\frac{v^2}{c^2}}} ; \qquad t' = \frac {t-\frac{vx}{c^2}}{\sqrt{1-\frac{v^2}{c^2}}}</math></center>
These formulae are... quite general, applying to any event in line with two uniformly moving observers. If we let c become infinite then the ratio of v to c tends to zero and the formulae become<center><math>x' = x - vt ; \qquad t' = t</math></center>.
The Structure of the Universe: An Introduction to Cosmology (1949)

Source: Sailing the Wine-Dark Sea: Why the Greeks Matter (2003), Ch.IV The Politician and the Playwright: How to Rule

The Great Dictator (1940), The Barber's speech
Context: I'm sorry, but I don't want to be an emperor. That's not my business. I don't want to rule or conquer anyone. I should like to help everyone, if possible, Jew, gentile, black man, white. We all want to help one another. Human beings are like that. We want to live by each other's happiness — not by each other's misery. We don't want to hate and despise one another.
In this world there is room for everyone. And the good earth is rich and can provide for everyone. The way of life can be free and beautiful, but we have lost the way. Greed has poisoned men's souls, has barricaded the world with hate, has goose-stepped us into misery and bloodshed. We have developed speed, but we have shut ourselves in. Machinery that gives abundance has left us in want. Our knowledge has made us cynical. Our cleverness, hard and unkind. We think too much and feel too little. More than machinery we need humanity. More than cleverness we need kindness and gentleness. Without these qualities, life will be violent and all will be lost.
The aeroplane and the radio have brought us closer together. The very nature of these inventions cries out for the goodness in men, cries out for universal brotherhood, for the unity of us all. Even now my voice is reaching millions throughout the world — millions of despairing men, women and little children — victims of a system that makes men torture and imprison innocent people. To those who can hear me, I say — do not despair. The misery that is now upon us is but the passing of greed — the bitterness of men who fear the way of human progress. The hate of men will pass, and dictators die, and the power they took from the people will return to the people and so long as men die, liberty will never perish.
Soldiers! Don't give yourselves to brutes — men who despise you — enslave you — who regiment your lives — tell you what to do — what to think or what to feel! Who drill you, diet you, treat you like cattle, use you as cannon fodder. Don't give yourselves to these unnatural men — machine men with machine minds and machine hearts! You are not machines! You are not cattle! You are men! You have the love of humanity in your hearts. You don't hate! Only the unloved hate — the unloved and the unnatural!
Soldiers! Don't fight for slavery! Fight for liberty! In the 17th Chapter of St. Luke it is written: "the Kingdom of God is within man" — not one man nor a group of men, but in all men! In you! You, the people have the power — the power to create machines. The power to create happiness! You, the people, have the power to make this life free and beautiful, to make this life a wonderful adventure.
Then, in the name of democracy, let us use that power! Let us all unite! Let us fight for a new world, a decent world that will give men a chance to work, that will give youth the future and old age a security. By the promise of these things, brutes have risen to power, but they lie! They do not fulfill their promise; they never will. Dictators free themselves, but they enslave the people! Now, let us fight to fulfill that promise! Let us fight to free the world, to do away with national barriers, to do away with greed, with hate and intolerance. Let us fight for a world of reason, a world where science and progress will lead to all men's happiness.
Soldiers! In the name of democracy, let us all unite!
[Cheers]
Hannah, can you hear me? Wherever you are, look up, Hannah. The clouds are lifting. The sun is breaking through. We are coming out of the darkness into the light. We are coming into a new world, a kindlier world, where men will rise above their hate, their greed and brutality. Look up, Hannah. The soul of man has been given wings, and at last he is beginning to fly. He is flying into the rainbow — into the light of hope, into the future, the glorious future that belongs to you, to me and to all of us. Look up, Hannah. Look up.

1961, Inaugural Address
Context: So let us begin anew — remembering on both sides that civility is not a sign of weakness, and sincerity is always subject to proof. Let us never negotiate out of fear. But let us never fear to negotiate.
Let both sides explore what problems unite us instead of belaboring those problems which divide us. [... ] Let both sides seek to invoke the wonders of science instead of its terrors. Together let us explore the stars, conquer the deserts, eradicate disease, tap the ocean depths, and encourage the arts and commerce.
Let both sides unite to heed in all corners of the earth the command of Isaiah — to "undo the heavy burdens … and to let the oppressed go free."

Special message to the Congress on National Health Needs (65)" (27 February 1962) http://www.jfklibrary.org/Research/Research-Aids/Ready-Reference/JFK-Quotations.aspx
1962