Karl Popper

1902–1994 · Austrian-British philosopher of science and social and política e falsificationi

Topics: learning, debugging, simplicity, software design

• When I speak of reason or rationalism, all I mean is the conviction that we can learn through criticism of our mistakes and errors, especially through criticism by others, and eventually also through self-criticism.

  — Karl Popper

• 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.

  — Karl Popper

• A principle of induction would be a statement with the help of which we could put inductive inferences into a logically acceptable form.

  — Karl Popper

• 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.

  — Karl Popper

• Our aim as scientists is objective truth; more truth, more interesting truth, more intelligible truth. We cannot reasonably aim at certainty. Once we realize that human knowledge is fallible, we realize also that we can never be completely certain that we have not made a mistake.

  — Karl Popper

• There are all kinds of sources of our knowledge; but none has authority ... The fundamental mistake made by the philosophical theory of the ultimate sources of our knowledge is that it does not distinguish clearly enough between questions of origin and questions of validity.

  — Karl Popper

• 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.

  — Karl Popper

• Never aim at more precision than... required by the problem...

  — Karl Popper

• Next to art, or even equal to it, science – that is, producing and testing theories about the world, about reality – seems to me to be the greatest creative enterprise of which men are capable.

  — Karl Popper

• 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.

  — Karl Popper

• But science is one of the very few human activities — perhaps the only one — in which errors are systematically criticized and fairly often, in time, corrected.

  — Karl Popper

• Science must begin with myths, and with the criticism of myths.

  — Karl Popper

• If the many, the specialists, gain the day, it will be the end of science as we know it - of great science. It will be a spiritual catastrophe comparable in its consequences to nuclear armament.

  — Karl Popper

• There is no method of discovering a scientific theory.

  — Karl Popper

• [S]ubject matters in general do not exist. There are no subject matters; no branches of learning—or, rather, of inquiry: there are only problems, and the urge to solve them.

  — Karl Popper

• 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.

  — Karl Popper

• 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.

  — Karl Popper

• Science may be described as the art of systematic over-simplification — the art of discerning what we may with advantage omit.

  — Karl Popper

• Since we can never know anything for sure, it is simply not worth searching for certainty; but it is well worth searching for truth; and we do this chiefly by searching for mistakes, so that we have to correct them.

  — Karl Popper

• What can be said can and should always be said more and more simply and clearly.

  — Karl Popper