Re: cracks and pots

when i said

eg, if you look at grothendieck's work, he started working in algebra, and ended up developing foundational structures, because he needed them.

i meant that he ended up working on toposes, fibrations, and descent (as foundational structures). i did not mean that he observed the grothendieck universes (which are perhaps foundational, but not much of a structure), as my hasty formulation had suggested to some people. sorry about the confusion (and about taking bandwidth to correct it), -- dusko