“Liberty is always dangerous, but it is the safest thing we have.”

"The Limits of Mother Love", in The New York Times Book Review, March 31, 1985

Speech, Constitutional Convention (29 June 1787), from Max Farrand's Records of the Federal Convention of 1787, Vol. I http://memory.loc.gov/cgi-bin/ampage?collId=llfr&fileName=001/llfr001.db&recNum=494&itemLink=D?hlaw:5:./temp/~ammem_kmli::%230010495&linkText=1 (1911), p. 465
1780s
Context: In time of actual war, great discretionary powers are constantly given to the Executive Magistrate. Constant apprehension of War, has the same tendency to render the head too large for the body. A standing military force, with an overgrown Executive will not long be safe companions to liberty. The means of defence against foreign danger have been always the instruments of tyranny at home. Among the Romans it was a standing maxim to excite a war, whenever a revolt was apprehended. Throughout all Europe, the armies kept up under the pretext of defending, have enslaved the people.

Speech to 1922 Committee (19 July 1984) http://www.margaretthatcher.org/document/105563, quoted in John Campbell, Margaret Thatcher. The Iron Lady (London: Jonathan Cape, 2003), p. 361.
Second term as Prime Minister

Interview for Racing is in My Blood, 1991 http://www.youtube.com/watch?v=vzlKNyopKUI

The actual interview footage https://www.youtube.com/watch?v=ViXeYxHfYiw

Source: Fool's Fate

A Declaration of the Independence of Cyberspace (1996)
Context: Governments of the Industrial World, you weary giants of flesh and steel, I come from Cyberspace, the new home of Mind. On behalf of the future, I ask you of the past to leave us alone. You are not welcome among us. You have no sovereignty where we gather.
We have no elected government, nor are we likely to have one, so I address you with no greater authority than that with which liberty itself always speaks. I declare the global social space we are building to be naturally independent of the tyrannies you seek to impose on us. You have no moral right to rule us nor do you possess any methods of enforcement we have true reason to fear.
Governments derive their just powers from the consent of the governed. You have neither solicited nor received ours. We did not invite you. You do not know us, nor do you know our world. Cyberspace does not lie within your borders.

Address at the National Archives dedicating a shrine for the Declaration of Independence, the Constitution, and the Bill of Rights (15 December 1952) https://trumanlibrary.org/calendar/viewpapers.php?pid=2102
Context: Of course, there are dangers in religious freedom and freedom of opinion. But to deny these rights is worse than dangerous, it is absolutely fatal to liberty. The external threat to liberty should not drive us into suppressing liberty at home. Those who want the Government to regulate matters of the mind and spirit are like men who are so afraid of being murdered that they commit suicide to avoid assassination.
All freedom-loving nations, not the United States alone, are facing a stern challenge from the Communist tyranny. In the circumstances, alarm is justified. The man who isn't alarmed simply doesn't understand the situation — or he is crazy. But alarm is one thing, and hysteria is another. Hysteria impels people to destroy the very thing they are struggling to preserve.
Invasion and conquest by Communist armies would be a horror beyond our capacity to imagine. But invasion and conquest by Communist ideas of right and wrong would be just as bad.
For us to embrace the methods and morals of communism in order to defeat Communist aggression would be a moral disaster worse than any physical catastrophe. If that should come to pass, then the Constitution and the Declaration would be utterly dead and what we are doing today would be the gloomiest burial in the history of the world.