Karl Popper on freedom

The game of science is, in principle, without end. He who decides one day that scientific statements do not call for any further test, and that they can be regarded as finally verified, retires from the game.

Scientists try to eliminate their false theories, they try to let them die in their stead. The believer⁠—whether animal or man⁠—perishes with his false beliefs.

Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve.

The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.

Thomas Jefferson1743–1826Letter to William Stephens Smith (13 November 1787). Manuscript at the Library of Congress.

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The condition upon which God hath given liberty to man is eternal vigilance.

John Philpot Curran1750–1817Often credited to Thomas Jefferson

They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.

Benjamin Franklin1706–1790This was first used by Franklin for the Pennsylvania Assembly in its “Reply to the Governor” (November 11, 1755) Reply to the Governor

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