There are some interesting general issues which arise out of this correspondence and which could merit further discussion. 1) Having tried and trying to write some background history to a result or theory I am aware of how much work is entailed, and the difficulty of getting it right, so I have sympathy with those complained against. I remember one writer's reaction to a complaint that he did not give enough reference to past work was `it was easier to work it out myself than to read all the relevant literature'. There is historian's ethic here which is important but is somewhat in opposition to the hard job of getting the mathematics correct, in the best format, and publishable. 2) On the other hand appropriate credit is important. Friends will know that I have had my own complaints about `convenient categories for topology' although Eilenberg growled at me once: `Why are you making such a fuss?' Another reaction (G.W. Whitehad) was:`There is no reason why you should not get credit for work you have done.' Credit is important also for the balance and the future of the mathematics and is the more so in these days of research assessment. So my sympathies are also with Jean! 3) In such assessment there is now more importance placed on citations, especially fairly immediate ones. The problems in this are well known, and are illustrated by this discussion. Citations are a bit like the shadows on the wall of Plato's cave, and are only a sparse image of reality. Some forgetful pseudo-functor is clearly involved! There are no agreed rules, certainly no laws; all there is some general feeling that appropriate credit should be given, and often referees or editors have to point out omissions, which can be due to any of: ignorance, forgetfullness, laziness, prejudice, or moral hazard, more likely some of the first three. On forgetfullness, there is the story of Henry Whitehead giving a problem to a research student, who came back 2 weeks later with the comment:`But Henry, you solved this problem in one of your papers!' People have sometimes reacted to me when I came out with a bright idea: `Aah, at last you have seen it!' There is also the question of how far back citations should go? in other words, how long should be the reference list? So the current emphasis on citations in research assessment, and the large business built on it, have a strong element of absurdity. 4) I sometimes wonder if our career structure should not have more in common with music, where the profession and the study involves: performance, composition, musicology, but in all cases involves an assessment of `musicality', as well as technique. 5) The issues Jean raises in his last email on the reasons for the study of a subject are also very important. As Philip Hall was reported to have remarked: `It is important to study the algebra which arises from the geometry, rather than to force the geometry into a standard and known mould.' 6) I do agree it is important for people to speak out on important past trends and influences, and so to show what were the intuitions which inspired an area of work. Not all the aims may have been achieved! I agree that changes of published, cited and accepted terminology has its dangers as have been pointed out by Jean in previous correspondence, with respect to cartesian and cocartesian morphisms. The problem is still that language does and should evolve. Ronnie [For admin and other information see: http://www.mta.ca/~cat-dist/ ]