Supports· strongZW-E008
Hardy 2001: one word — 'continuous' — separates quantum from classical
- what the source states
- Five axioms, of which the first four are consistent with both quantum and classical probability theory; the fifth requires "continuous reversible transformations between pure states." Dropping the word "continuous" yields classical probability theory instead of quantum theory.
- what we infer
- The cleanest possible statement of what any observer-first program ultimately owes an explanation for: not wavefunctions or Hilbert spaces, but one structural fact — continuity of reversible change — whose deeper origin the reconstruction literature itself leaves open.
- limitations
- Never journal-published; its axioms were later refined by successor reconstructions.