PhronesisThe shared surface
Across the hard problems the same shape keeps showing up. The generating rule is cheap — knowable, compressible: the equations of motion, the codon table, the Schrödinger equation, a grammar, the rules of a game. The realized outcome is not: there seems to be no way to obtain it except to let the system run. The present — the happening, the occurrence — is the name for that running. Structure knowable; happening un-shortcuttable.
It is tempting to call this one thing, one ground under every wall. That is the move this note refuses. The surface is shared. The mechanism underneath is not — and the difference matters more than the likeness.
Four mechanisms, not one
Pull "can't be shortcut" apart and at least four distinct reasons fall out. They are not the same "can't."
iComputational irreducibility. The outcome is fully determined from the start, but there is no formula or shortcut faster than performing the steps — to know the end you must run the computation (Wolfram). This is the tight case for a developing embryo computing its own form, for a game computing its own result, for a generic dynamical system over the long run. Determined, knowable in principle, and still only reachable by doing.
iiChaotic unpredictability. Adjacent, but not the same. Here the limit is not computation length but precision: deterministic systems with sensitive dependence on initial conditions (Lorenz) amplify any measurement error exponentially, on a timescale set by the Lyapunov exponent. The weather is determined and information-starved: you fail to predict it not because the math is irreducible but because you can never measure the present finely enough. A different wall, often mistaken for the first.
iiiQuantum indeterminacy. Different in kind. On the standard reading the specific outcome is not determined-then-hidden; it is genuinely not-yet-fixed until measurement, with the Born rule giving only probabilities. This is not "determined but hard" — it is, apparently, ontologically open. And honestly, the wall even moves: under Bohmian mechanics or many-worlds the determinism returns in another form. So this case is not only a different mechanism but an interpretation-dependent one.
ivSemantic and phenomenal givenness. Not about computation or chance at all. A symbol cannot be shortcut to its meaning because reference bottoms out in contact with a world — the symbol grounding problem (Harnad). Experience cannot be shortcut from structure because "what it is like" is not entailed by any functional description — the hard problem (Chalmers). These are failures of derivation across a gap, not of prediction. A wholly different axis.
What is actually shared
The unity is at the level of access, not mechanism.
What survives is thinner and sturdier than "one ground." In every case the only access to the result is the occurrence — you cannot get the answer except by letting the thing happen. But the reason you cannot differs each time: no shortcut algorithm; no sufficient precision; no prior fact of the matter; no derivation across a semantic or phenomenal gap. These domains feel like one because you stand in the same posture toward all of them — waiting on the happening — not because one physics runs underneath.
Why the distinction is the point
Collapsing an access-sameness into a mechanism-identity is precisely the error of the grand unifier — "it is all one energy, one code, one field." The collapse is seductive because the felt unity is genuine. But the work is the opposite of the collapse. The honest unification is small: a single shared fact about access. Everything else — the four mechanisms — must be kept apart, because they behave differently, fail differently, and would be tested differently.
None of the four distinctions is new; each is argued in its own literature. What this note offers is the organizing axis: access-sameness versus mechanism-identity as the lens that both explains why these problems feel like siblings and dissolves the temptation to treat them as one. Offered for argument, not as a result — a working note, not a theorem.
Background to The Logic of the Circle and Sports, the Present Sold — the honest version of their "same ground." The ground is shared; the floors beneath it are not.