From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6144 Path: news.gmane.org!not-for-mail From: JeanBenabou Newsgroups: gmane.science.mathematics.categories Subject: Re: Evil in bicategories Date: Sun, 12 Sep 2010 14:38:09 +0200 Message-ID: References: Reply-To: JeanBenabou NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 (Apple Message framework v753.1) Content-Type: text/plain; charset=ISO-8859-1; delsp=yes; format=flowed Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1284320990 4528 80.91.229.12 (12 Sep 2010 19:49:50 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sun, 12 Sep 2010 19:49:50 +0000 (UTC) Cc: categories To: David Leduc Original-X-From: majordomo@mlist.mta.ca Sun Sep 12 21:49:49 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from smtpx.mta.ca ([138.73.1.138]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1OusYb-0005jg-E4 for gsmc-categories@m.gmane.org; Sun, 12 Sep 2010 21:49:45 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:59157) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1OusX6-0007zp-M8; Sun, 12 Sep 2010 16:48:12 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1OusX4-0001yt-Dx for categories-list@mlist.mta.ca; Sun, 12 Sep 2010 16:48:10 -0300 In-Reply-To: Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6144 Archived-At: Dear all, Although I'm not a very "religious" person, I respect all religions, =20 and I also deeply respect, of course, Category Theory. I hope someone =20= will answer the following question: Is Category Theory a religion? As far as I know, it is the only part of mathematics (or of many =20 other sciences) where words such as "dogma", "doctrine" (let alone =20 hyper ones) are used. Recently a few other words with the same =20 religious connotation have been added. The most frequent one being "evil" Maybe my english isn't so "beautiful", but in all cases where "evil" =20 has been used, what is wrong with "wrong" instead? Le 11 sept. 10 =E0 04:05, David Leduc a =E9crit : > > In a bicategory, composition of 1-cells is associative up to > isomorphism. Because it would be evil to insist that h o (g o f) is > equal to (h o g) o f. However the source and target objects of those > compositions must be equal. Isn't it evil? Why not weaken this > requirement by saying that the sources (respectively, targets) of h o > (g o f) and (h o g) o f must only be isomorphic? > [For admin and other information see: http://www.mta.ca/~cat-dist/ ]