Lawvere and Leibniz

Hi all, here is an philosophy article perhaps of interest to some on the list http://www.newappsblog.com/2011/11/the-truth-about-infinitesimals.html discussing the contrast between the 'old' solution (Weierstrass et al) to non-rigorous calculus a la Leibniz and the new solutions, nonstandard analysis and SDG, but mostly the latter. Not all ideas are credited, so only Lawvere is mentioned, and not Grothendieck, A. Kock, or others who contributed to the development of the philosophy of 'infinitesimals' in geometry. I think it is a nice advertisement for category theory, even mentioning the phrase 'The world or category of smooth spaces and smooth maps...'. David [For admin and other information see: http://www.mta.ca/~cat-dist/ ]