A quotation by Harald Bohr
To illustrate the strong feelings of independence which, as a part of the old traditions, are so characteristic of the English spirit, I should like to tell how Hardy and Littlewood, when they planned and began their far-reaching and intensive team work, still had some misgivings about it because they feared that it might encroach on their personal freedom, so vitally important to them. Therefore, as a safety measure, . . . they amused themselves by formulating some so-called 'axioms' for their mutual collaboration. There were in all four such axioms.
The first of them said that, when one wrote to the other, . . ., it was completely indifferent whether what they wrote was right or wrong . . .
The second axiom was to the effect that, when one received a letter from the other, he was under no obligation whatsoever to read it, let alone to answer it . . .
The third axiom was to the effect that, although it did not really matter if they both thought about the same detail, still, it was preferable that they should not do so.
And, finally, the fourth, and perhaps most important axiom, stated that it was quite indifferent if one of them had not contributed the least bit to the contents of a paper under their common name . . .
I think one may safely say that seldom -- or never -- was such an important and harmonious collaboration founded on such apparently negative axioms.