The quotations of

Karl Popper

Austrian-British philosopher of science and social and política e falsificationism and for criticism of Plato, Hegel and Marx as totalitarian opponents of open society

1902–1994

18 quotes, most often on Science, Freedom and Thinking.

We must plan for freedom, and not only for security, if for no other reason than that only freedom can make security secure.
The Open Society and Its Enemies (1945), Vol. 2, Ch. 21 “An Evaluation of the Prophecy”
- 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.
The Logic of Scientific Discovery (1934), Ch. 2 “On the Problem of a Theory of Scientific Method”, Section 11: Methodological Rules as Conventions, p. 32.
- Science
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.
Epistemology Without A Knowing Subject (1967)
- Science
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.
Objective Knowledge: An Evolutionary Approach (1972)
- Ideas
- Thinking
We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant.
The Open Society and Its Enemies (1945), Vol. 1, Notes to the Chapters: Ch. 7, Note 4
- Freedom
- Politics
I believe that there is, from the ethical point of view, no symmetry between suffering and happiness, or between pain and pleasure.
The Open Society and Its Enemies (1945), Vol. 1, Notes to the Chapters: Ch. 9, Note 2.
- Happiness
- Morality
There is no history of mankind, there is only an indefinite number of histories of all kinds of aspects of human life.
The Open Society and Its Enemies (1945), Vol. 2, Ch. 25 “Has History any Meaning?”
- History
If we are uncritical we shall always find what we want: we shall look for, and find, confirmations, and we shall look away from, and not see, whatever might be dangerous to our pet theories.
The Poverty of Historicism (1957) Ch. 29 The Unity of Method
- Science
- Thinking
The true Enlightenment thinker, the true rationalist, never wants to talk anyone into anything. No, he does not even want to convince; all the time he is aware that he may be wrong.
On Freedom (1958)
- Debate
- Wisdom
The more we learn about the world, and the deeper our learning, the more conscious, specific, and articulate will be our knowledge of what we do not know, our knowledge of our ignorance.
Conjectures and Refutations: The Growth of Scientific Knowledge (1963)
- Knowledge
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.
On Freedom (1958)
- Freedom
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 Open Society and Its Enemies (1945), Vol. 1, Notes to the Chapters: Ch. 7, Note 4
- Freedom
All things living are in search of a better world.
In Search of a Better World (1984), Preface
- Hope
Science must begin with myths, and with the criticism of myths.
Conjectures and Refutations: The Growth of Scientific Knowledge (1963), Ch. 1 “Science: Conjectures and Refutations”, Section VII
- Science
We may become the makers of our fate when we have ceased to pose as its prophets.
The Open Society and Its Enemies (1945), Introduction
- Responsibility

Most quoted

People A to Z

C. S. Lewis1898–1963151 quotes

Mark Twain1835–1910151 quotes

Benjamin Franklin1706–179098 quotes

Martin Luther King Jr.1929–196884 quotes

Albert Einstein1879–195595 quotes

Dave Barryborn 1947100 quotes