“Freedom is an indivisible value and when the freedom of one is threatened the freedom of all is in jeopardy.”

Freedom

Speech to Conservative Central Council ("The Historic Choice") (20 March 1976) http://www.margaretthatcher.org/document/102990
Leader of the Opposition
Context: There are others who warn not only of the threat from without, but of something more insidious, not readily perceived, not always deliberate, something that is happening here at home. What are they pointing to? They are pointing to the steady and remorseless expansion of the Socialist State. Now none of us would claim that the majority of Socialists are inspired by other than humanitarian and well-meaning ideals. At the same time few would, I think, deny today that they have made a monster that they can't control. Increasingly, inexorably, the State the Socialists have created is becoming more random in the economic and social justice it seeks to dispense, more suffocating in its effect on human aspirations and initiative, more politically selective in its defence of the rights of its citizens, more gargantuan in its appetite—and more disastrously incompetent in its performance. Above all, it poses a growing threat, however unintentional, to the freedom of this country, for there is no freedom where the State totally controls the economy. Personal freedom and economic freedom are indivisible. You can't have one without the other. You can't lose one without losing the other.

The Economics of Success (D. van Nostrand & Co., 1963), pp. 291–292

1963, Ich bin ein Berliner
Context: Freedom is indivisible, and when one man is enslaved, all are not free. When all are free, then we can look forward to that day when this city will be joined as one and this country and this great Continent of Europe in a peaceful and hopeful globe. When that day finally comes, as it will, the people of West Berlin can take sober satisfaction in the fact that they were in the front lines for almost two decades.
All free men, wherever they may live, are citizens of Berlin, and, therefore, as a free man, I take pride in the words "Ich bin ein Berliner."

1950s, First Inaugural Address (1953)

Source: The Russian Revolution (1918), Chapter Six, "The Problem of Dictatorship"

Speech delivered at the second congress of the peace partisans (April 14, 1959).
Principles of the 14th July Revolution (1959)

Essay, written under the pseudonym "Candidus," in The Boston Gazette (14 October 1771) http://www.gutenberg.org/etext/2092, later published in The Life and Public Services of Samuel Adams (1865) by William Vincent Wells, p. 425

Strictly Personal, ch. 31 (1941)