In the book "Elementary Number Theory" (Chelsea, New York, 1958. An English translation of vol. 1 of the German book Vorlesungen ueber Zahlentheorie), p.31, the author, Edmund Landau, mentions the question whether the infinite series $\sum \mu(n)/n$ converges (TEX notation; \mu is the Moebius function). After giving a reference to the answer in Part 7 of the same V.u.Z, and without saying what the answer is, Landau writes: "Gordan used to say something to the effect that "Number Theory is useful since one can, after all, use it to get a doctorate with." In 1899 I received my doctorate by answering this question."
So even if Bourbaki said something similar about logic, it certainly was not an original sentiment.
From troubled Jerusalem
On Fri, 8 Oct 2004, Jose Ferreiros wrote:
> > > Dear friends, > > I remember having once read or heard the following anecdote about some > Bourbaki member. He (maybe Dieudonne) should have said that the usefulness > of mathematical logic consists in that graduate students can write a > dissertation on the topic. The implication was clearly that this is not > serious mathematics, but Ok before one is ready to do serious things. > > The problem is that I don't know whether the anecdote is reliable, and I > cannot remember who may have told it. Remember that one should not trust all > that one hears. Can anyone help? > > Thanks and all the best, > > Jose Ferreiros