“Indeed there has never been any explanation of the ebb and flow in our veins--of happiness and unhappiness.”

Presidency (1977–1981), Farewell Address (1981)
Context: I have just been talking about forces of potential destruction that mankind has developed, and how we might control them. It is equally important that we remember the beneficial forces that we have evolved over the ages, and how to hold fast to them.
One of those constructive forces is enhancement of individual human freedoms through the strengthening of democracy, and the fight against deprivation, torture, terrorism and the persecution of people throughout the world. The struggle for human rights overrides all differences of color, nation or language.
Those who hunger for freedom, who thirst for human dignity, and who suffer for the sake of justice — they are the patriots of this cause.
I believe with all my heart that America must always stand for these basic human rights — at home and abroad. That is both our history and our destiny.
America did not invent human rights. In a very real sense, it is the other way round. Human rights invented America.
Ours was the first nation in the history of the world to be founded explicitly on such an idea. Our social and political progress has been based on one fundamental principle — the value and importance of the individual. The fundamental force that unites us is not kinship or place of origin or religious preference. The love of liberty is a common blood that flows in our American veins.

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 101.

Arthur's first summary
The Nemesis of Faith (1849)
Context: To be enthusiastic about doing much with human nature is a foolish business indeed; and, throwing himself into his work as he was doing, and expecting so much from it, would not the tide ebb as strongly as it was flowing? It is a rash game this setting our hearts on any future beyond what we have our own selves control over. Things do not walk as we settle with ourselves they ought to walk, and to hope is almost the correlative of to be disappointed.

Source: Iced

Plato, Phaedo

Source: Kitchen

Source: The Theory of Evolution (1958), p. xv.

On n'est jamais si heureux ni si malheureux qu'on s'imagine.
Maxim 49.
Reflections; or Sentences and Moral Maxims (1665–1678)

As quoted by Afsané Bassir, Interview with Prince Reza Pahlavi, son of the late Shah of Iran http://www.rezapahlavi.org/details_article.php?article=50&page=7, Le Monde, June 6, 2001.
Interviews, 2001-2002
Context: I say, listen to the Iranians. During twenty-two years, you forgot the Iranians, they are close to 70 millions today who hanker for liberty. I say to the west: the oil that flows in your pipelines is not more important than the blood that flows in the veins of Iranians.