Hello 1) I agree completely with Andre, or, more properly, with Samuel Eilemberg and Pierre Cartier (Andre just tel us what they said to him when he ask them the question) So the problem is not wether to agree with Andre or not, but wether to agree with Eilemberg-Cartier or not. They said to Andre: "Bourbaki had essentially two options: rewrite the whole treaty using categories, or just introduce them in the book on homological algebra, The second option won, essentially because of the enormity of the task of rewriting everything." 2) We can see that this makes sense too, the Bourbaki Tractate was already written, and Grothendieck's proposal was to entirely rewrite the thing !! 3) Also, Bourbaki Tractate, as it is, is a masterful book. It is just perfect, or as close to perfection as possible. It sets a way, philosophy and style to write mathematics. I myself (as Andre) have learned a lot by reading Bourbaki, and, more than that, I enjoyed the reading (and the task to understand it) as much as I enjoy any reading where I can see perfection in every sense (as in Borges for example). 4) So, it is a lost for mathematics and for category theory that category theory fit in Bourbaki's goal as a foundational theory (as set theory is) , and not just as one more part of mathematics (as set theory is not). What a marvelous book just on category theory Bourbaki could have written, can you imagine !! A Boubaki book on category theory !! We miss it . . . 5) Concerning "desdain", I recall to all of you that most of the people who show desdain for category theory, also show desdain for Bourbaki. Eduardo.