I do not see why I should be polite to tyrants, who slobber of humanitarianism and think only of their own petty interests.

No theory ever agrees with all the facts in its domain, yet it is not always the theory that is to blame. Facts are constituted by older ideologies, and a clash between facts and theories may be proof of progress. It is also a first step in our attempt to find the principles implicit in familiar observational notions.

Rationalism... is a secularized form of the belief in the power of the word of God.

The world we inhabit is abundant beyond our wildest imagination. There are trees, dreams, sunrises; there are thunderstorms, shadows, rivers; there are wars, flea bites, love affairs; there are the lives of people, Gods, entire galaxies. The simplest human action varies from one person and occasion to the next-how else would we recognize our friends only from their gait, posture, voice, and divine their changing moods? Only a tiny fraction of this abundance affects our minds. This is a blessing, not a drawback.

A free society is a society in which all traditions have equal rights and equal access to the centers of power. A tradition receives these rights not because the importance the cash value, as it were) it has for outsiders but because it gives meaning to the lives of those who participate in it.

There is not a single rule, however plausible, and however firmly grounded in epistemology, that is not violated at some time or other. It becomes evident that such violations are not accidental events, they are not results of insufficient knowledge or of inattention which might have been avoided. On the contrary, we see that they are necessary for progress.

The material which a scientist actually has at his disposal, his laws, his experimental results, his mathematical techniques, his epistemological prejudices, his attitude towards the absurd consequences of the theories which he accepts, is indeterminate in many ways, ambiguous, and never fully separated from the historical background . This material is always contaminated by principles which he does not know and which, if known, would be extremely hard to test.