I am ready to take back my criticism and apologize, if the "longer sentence" is correct. But is it? I am certainly not an expert in Bourbaki history, and, as far as I remember, they say no word about morphisms in the historical part of "Theory of Sets" and give no references on categories. But I think they "always" believed that structures determine isomorphisms but not morphisms, and I don't think they changed their mind between 1951 and 1957. When I say "they" I mean "those of them who made main decisions about the Bourbaki tractate". Because I hope (!) that not all of them were happy that categories are not even defined in the tractate. In my previous message I wrote "Removing Bourbaki's formalism..." but in fact that "formalism" is (not nice but) serious, in the sense that it takes us further away from abstract categories. Anyway, we need to know, if it is still possible, how exactly did Bourbaki definition of morphism(s) came up. George -------------------------------------------------- From: "Colin McLarty" <colin.mclarty@case.edu> Sent: Wednesday, May 23, 2012 1:06 AM To: "George Janelidze" <janelg@telkomsa.net> Cc: <categories@mta.ca> Subject: Re: categories: Re: Bourbaki & category theory
On Tue, May 22, 2012 at 5:51 PM, George Janelidze <janelg@telkomsa.net> wrote:
Dear Colleagues,
I don't think it is good to say that "Bourbaki had a notion of isomorphism but no general notion of morphism", even in a brief message!
It would not be good -- unless it was part of a longer sentence.
I wrote "Prior to encountering category theory, Bourbaki had a notion of isomorphism but no general notion of morphism." The Bourbaki passage you quote was first published in 1957, at least 6 years after Bourbaki encountered category theory as shown by the letter from Weil that i quoted.
best, Colin
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