[conz]

  Have these rigidly regulated mechanisms been in place for 2500 years? Because if not, that seems like the sort of thing that Feyrabend might have meant by saying science isn't a single tradition.

The programme/process of Science - the overarching belief that the natural world can be understood through rational means - has itself gone through numerous process improvements during those 2500 years; yet it remains the same endeavour and retains the same core impetus.

[philh]

Okay, but it seems like "science isn't a single tradition" is a perfectly reasonable way to describe this state of affairs. So when you ask "what does this even mean" I think there's a fairly straightforward answer.