Riddles of induction – old or new, Hume’s or Goodman’s – pose unanswered challenges to assumptions that experiences logically legitimate expectations or classifications. The challenges apply both to folk beliefs and to scientific ones. In particular, Goodman’s ‘new riddle’ famously confounds efforts to specify how additional experiences confirm the rightness of currently preferred ways of organizing objects, i.e. our favored theories of what kinds there are.1 His riddle serves to emphasize that neither logic nor experience certifies accepted groupings of objects (...) into kinds.2 Hacking strongly endorses Goodman’s riddle and its chief consequences – nature does not dictate any organizing scheme to us, and different schemes need have no connection to one another. (shrink)