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.

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.

It is often assumed that science starts from facts and eschews counter-factual theories. Nothing could be further from the truth. What is one of the basic assumptions of the scientific world-view? That the variety of events that surrounds us is held together by a deeper unity.

The separation of state and church must be complemented by the separation of state and science, that most recent, most aggressive, and most dogmatic religious institution.

Traditions are neither good nor bad, they simply are... Rationality is not an arbiter of traditions, it is itself a tradition or an aspect of a tradition.

Those who violate the rules of a language do not enter new territory; they leave the domain of meaningful discourse. Even facts in these circumstances dissolve, because they are shaped by the language and subjected to its limitations.

Rational discourse is only one way of presenting and examining an issue and by no means the best. Our new intellectuals are not aware of its limitations and of the nature of the things outside.