We have become makers of our fate when we have ceased to pose as its prophets.

A system is empirical or scientific only if it is capable of being tested by experience. These considerations suggest that not the verifiability but the falsifiability of a system is to be taken as a criterion of demarcation... It must be possible for an empirical or scientific system to be refuted by experience.

Piecemeal social engineering resembles physical engineering in regarding the ends as beyond the province of technology.

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

It can't happen here is always wrong: a dictatorship can happen anywhere.

There is no history, only histories.

Reason like science, grows by way of mutual criticism; the only possible way of planning its growth is to develop those institutions that safeguard. the freedom of thought