Research programmes, besides their negative heuristic, are also characterized by their positive heuristic.

That sometimes clear ... and sometimes vague stuff ... which is ... mathematics.

The great scientific achievements are research programmes which can be evaluated in terms of progressive and degenerative problemshifts; and scientific revolutions consist of one research programme superceding (overtaking in progress) another. This methodology offers a new rational reconstruction of science.

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

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

The proving power of the intellect or the senses was questioned by the skeptics more than two thousand years ago; but they were browbeaten into confusion by the glory of Newtonian physics.

No experimental result can ever kill a theory: any theory can be saved from counterinstances either by some auxiliary hypothesis or by a suitable reinterpretation of its terms.