Why are scientists so reluctant to let go of Koch’s postulates even though they often chafe—as Koch did—under their restrictions? Why are Koch’s postulates, with all their problems, still as relevant...

Why are scientists so reluctant to let go of Koch’s postulates even though they often chafe—as Koch did—under their restrictions? Why are Koch’s postulates, with all their problems, still as relevant today as they were when Koch first proposed them?