Re: Fundamental Theorem of Category Theory?

Dear all, I strongly agree to Ellis Gould's quote of Bill Lawvere's remark on the Yoneda Lemma:

-- a mathematical theory corresponds "roughly to the definition of a class of mathematical objects"

One of the most important points in category theory are universal properties. The existence of universal solutions is equivalent to the representability of certain functors - at least under reasonable smallness conditions. This is closely related to the Yoneda Lemma; therefore it is really one of the fundamental theorems to me. Greetinge Reinhard [For admin and other information see: http://www.mta.ca/~cat-dist/ ]