The history of science, like the history of all human ideas, is a history of irresponsible dreams, of obstinacy, and of error.

Whenever we propose a solution to a problem, we ought to try as hard as we can to overthrow our solution, rather than defend it.

Genuine philosophical problems are always rooted outside philosophy and they die if these roots decay.

The initial stage, the act of conceiving or inventing a theory, seems to me neither to call for logical analysis nor to be susceptible of it.

We hate the very idea that our own ideas may be mistaken, so we cling dogmatically to our conjectures.

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.

It is a myth that the success of science in our time is mainly due to the huge amounts of money that have been spent on big machines. What really makes science grow is new ideas, including false ideas.