What is surprising is that almost all the trends that developed within the sciences, Aristotelianism and an extreme Platonism included, produced results, not only in special domains, but everywhere; there exist highly theoretical branches of biology and highly empirical parts of astrophysics. The world is a complex an many-sided thing.

It is clear, then, that the idea of a fixed method, or of a fixed theory of rationality, rests on too naive a view of man and his social surroundings. To those who look at the rich material provided by history, and who are not intent on impoverishing it in order to please their lower instincts, their craving for intellectual security in the form of clarity, precision, "objectivity," "truth," it will become clear that there is only one principle that can be defended under all circumstances and in all stages of human development. It is the principle: anything goes.

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.

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.

Copernicanism and other essential ingredients of modern science survived only because reason was frequently overruled in their past.

Experience arises together with theoretical assumptions not before them, and an experience without theory is just as incomprehensible as is (allegedly) a theory without experience.

The idea of a method that contains firm, unchanging, and absolutely binding principles for conducting the business of science meets considerable difficulty when confronted with the results of historical research. We find, then, that there is not a single rule, however plausible, and however firmly grounded in epistemology, that is not violated at some time or another.