Intellectual honesty consists in stating the precise conditions under which one will give up one's belief.

Philosophy of science without history of science is empty; history of science without philosophy of science is blind.

The classical example of a successful research programme is Newton's gravitational theory: possibly the most successful research programme ever.

Mathematics does not grow through a monotonous increase of the number of indubitably established theorems but through the incessant improvement of guesses by speculation and criticism, by the logic of proofs and refutations.

The history of mathematics, lacking the guidance of philosophy, [is] blind, while the philosophy of mathematics, turning its back on the most intriguing phenomena in the history of mathematics, is empty.

If even in science there is no a way of judging a theory but by assessing the number, faith and vocal energy of its supporters, then this must be even more so in the social sciences: truth lies in power.

Blind commitment to a theory is not an intellectual virtue: it is an intellectual crime.