“It is wrong to think that belief in freedom always leads to victory; we must always be prepared for it to lead to defeat. If we choose freedom, then we must be prepared to perish along with it.”

Part III, Epilogue, p. 204
2000s, How Life Imitates Chess (2007)

Speech at Omaha Beach on the 40th Anniversary of D-Day http://www.reagan.utexas.edu/archives/speeches/1984/60684b.htm (6 June 1984)
1980s, First term of office (1981–1985)

To My People (July 4, 1973)

UFC 178 post-event press conference https://www.youtube.com/watch?v=zAAC34JzxS0 (September 2014), Ultimate Fighting Championship, Zuffa, LLC
2010s, 2014

Source: Capitalism and Freedom (1962), Ch. 11, Social Welfare Measures, p. 187

Vol. 1, Notes to the Chapters: Ch. 7, Note 4
The Open Society and Its Enemies (1945)
Context: The so-called paradox of freedom is the argument that freedom in the sense of absence of any constraining control must lead to very great restraint, since it makes the bully free to enslave the meek. The idea is, in a slightly different form, and with very different tendency, clearly expressed in Plato.
Less well known is the paradox of tolerance: Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them. — In this formulation, I do not imply, for instance, that we should always suppress the utterance of intolerant philosophies; as long as we can counter them by rational argument and keep them in check by public opinion, suppression would certainly be unwise. But we should claim the right to suppress them if necessary even by force; for it may easily turn out that they are not prepared to meet us on the level of rational argument, but begin by denouncing all argument; they may forbid their followers to listen to rational argument, because it is deceptive, and teach them to answer arguments by the use of their fists or pistols. We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant. We should claim that any movement preaching intolerance places itself outside the law, and we should consider incitement to intolerance and persecution as criminal, in the same way as we should consider incitement to murder, or to kidnapping, or to the revival of the slave trade, as criminal.

1961, Address at the University of Washington
Context: No one should be under the illusion that negotiations for the sake of negotiations always advance the cause of peace. If for lack of preparation they break up in bitterness, the prospects of peace have been endangered. If they are made a forum for propaganda or a cover for aggression, the processes of peace have been abused. But it is a test of our national maturity to accept the fact that negotiations are not a contest spelling victory or defeat. They may succeed — they may fail. They are likely to be successful only if both sides reach an agreement which both regard as preferable to the status quo — an agreement in which each side can consider its own situation to be improved. And this is most difficult to obtain. But, while we shall negotiate freely, we shall not negotiate freedom. Our answer to the classic question of Patrick Henry is still no-life is not so dear, and peace is not so precious, "as to be purchased at the price of chains and slavery." And that is our answer even though, for the first time since the ancient battles between Greek city-states, war entails the threat of total annihilation, of everything we know, of society itself. For to save mankind's future freedom, we must face up to any risk that is necessary. We will always seek peace — but we will never surrender.

Source: Alone (1938), Ch. 6
Context: The things that mankind has tested and found right make for harmony and progress — or peace; and the things it has found wrong hinder progress and make for discord. The right things lead to rational behavior — such as the substitution of reason for force — and so to freedom. The wrong things lead to brute force and slavery.
But the peace I describe is not passive. It must be won. Real peace comes from struggle that involves such things as effort, discipline, enthusiasm. This is also the way to strength. An inactive peace may lead to sensuality and flabbiness, which are discordant. It is often necessary to fight to lessen discord. This is the paradox.