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 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.

One might get the impression that I recommend a new methodology which replaces induction by counterinduction and uses a multiplicity of theories, metaphysical views, fairy tales, instead of the customary pair theory/observation. This impression would certainly be mistaken. My intention is not to replace one set of general rules by another such set: my intention is rather to convince the reader that all methodologies, even the most obvious ones, have their limits.

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.

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.

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.

One knows quite well that harmony can be a harmony of appearances.