Foundational Questions

_{World Truths · Design document §5}

Four Foundational Axes govern the deep mechanisms of the pre-modern and industrial world. Each is resolved by a decisive experiment — a breakthrough that exists in every game, modelled on the experiment that settled the question in our own history. Until that experiment, rival theories coexist, each grants partial benefits, and each drives research — exactly as caloric theory productively drove real physics in our own history — Carnot built the theory of the heat engine on it.

What qualifies as a World Truth

A World Truth must be a fact that eventually makes different predictions — never a choice of description. Phlogiston was cut on this test (v3.71). A consistent phlogiston world is our own world described through missing oxygen: phlogiston behaves as a hole in oxygen, exactly as a semiconductor's positive charge-carriers are holes in its electrons. Its negative mass is the mass of the oxygen that is not there, so every weighing agrees with ours, and the account breaks only where it treats the hole as a thing — trying to isolate it, or mistaking it for hydrogen. Each remaining axis makes a claim some laboratory can decide (in our world, Joule's paddle-wheel, Snow's pump and Wöhler's urea decided three of them), so each is a genuine truth. The reasoning is kept in Combustion Physics (Model III).

Axis	Values (weights)	Decisive experiment	If an alternative is true
FQ9: Matter	Corpuscular (55%) / Substance-Elemental (25%) / Process-Elemental (20%)	CH19 (Systematic Element Analysis)	Substance-Elemental (Greek/Aristotelian): the four elements are fundamental and interconvertible — transmutation by recombination works. Opens CH20 (Transmutation Practice), CH21 (Philosopher's Stone). Process-Elemental (Chinese wu xing): the five phases and their generative/destructive cycles are real forces — transformation, not composition, is fundamental. Opens CH22 (Five-Phase Theory), CH23 (Generative Cycle Engine), CH24 (Phase-Destruction Warfare). Either elemental value forecloses the atomic spine (Nuclear Physics, Quantum Physics, semiconductor Computing never cohere) and instead opens the Quintessic Physics focus (QM-E chain) as the niche equivalent — deep matter theory, high-energy endgame power, and a resonance/cycle-logic computation substrate. CH06 (Periodic Table) dead-ends; Transmutation Practice (the Elemental Codex) or Five-Phase Theory (the Phase Codex) grants the MATTER_THEORY token instead.
FQ10: Disease	Germ (60%) / Miasma (20%) / Humoral (20%)	MD15 (Contagion Experiments — Pasteur's swan-neck flask)	All worlds suffer the same disease pressure (plague events, growth penalties in large/dense cities) — the phenomenon is fixed and gives nothing away early. What differs is only which counter works, and that isn't revealed until the decisive experiment (MD15). Germ: microbe control (MD05 → antibiotics). Miasma: MD16 (Miasma Engineering) — drainage and ventilation; only here does draining marsh/fen tiles yield a happiness bonus, and only here can foul air be weaponised. Humoral: MD17/MD18 — humour-balancing pharmacology and civic temperament. Because the counters differ only in form (all deliver comparable disease control) and none produces a distinctive early terrain effect, an experienced player cannot read the world's disease Truth from the map before running MD15. MD05 (Germ Theory) dead-ends in non-germ worlds; the others dead-end in germ worlds.
FQ11: Nature of Life	Mechanist (70%) / Vitalist (30%)	CH25 (Organic Synthesis Attempt — Wöhler's urea)	Vitalist: a measurable vital force separates living from dead matter, and synthesis-from-inorganic fails. Opens GN12 (Vital Essence Isolation — the Essence Reservoir), GN13 (Animating Principle — the Vital Automaton) and GN14 (Animate Intelligence). Organic Chemistry (CH07) still stands and still refines, but cannot create life's chemistry from dead matter; everything downstream reads LIFE_THEORY, which GN12 supplies.
FQ12: Nature of Heat	Kinetic (70%) / Caloric (30%)	TH10 (Mechanical Equivalent of Heat — Joule's paddle-wheel, Rumford's cannon)	Caloric: heat is a real conserved fluid. Opens TH11 (Caloric Storage — heat banked as a substance in Reservoirs and spent on Heat Exchanges) and TH12 (Caloric Projection — the Caloric Lance and Thermal Ward, fielded from banked heat). TH01's kinetic account dead-ends; the caloric model grants THERMO_THEORY instead.

Understanding Tokens

Downstream prerequisites never name a specific theory — they name the understanding it provides, so the practical tree is theory-agnostic. MATTER_THEORY comes from CH06, the Elemental Codex, or the Phase Codex; DISEASE_THEORY from MD05, MD16, or MD17; MASS_MEDICINE (empire-wide disease control) from MD06 (germ antibiotics), MD16 (miasma purification), or MD18 (humoral pharmacology); LIFE_THEORY from CH07 (mechanist) or GN12 (vitalist); THERMO_THEORY from TH01 (kinetic) or TH11 (caloric). Every prerequisite that names CH06, MD05, CH07, or TH01 is read as its token. The steam engine runs in a caloric world — its engineers simply understand it differently, and correctly for their universe, as Carnot did in ours.

The deep-physics tokens (Symmetry Principle)

Two further tokens let the late tree accept either the atomic or the elemental foundation without duplicating every downstream row:

• HIGH_ENERGY_PHYSICS — granted by NP02 (Atomic Model) in atomic worlds or QM-E01 (Quintessence Theory) in elemental worlds. Any breakthrough naming NP02, QP01, QP05, or QP08 as a prerequisite reads the token (the deep-high-energy and malleable-space primitives); in elemental worlds the Quintessic chain (QM-E01/QM-E04) satisfies it.
• EXOTIC_MATTER — granted by QP11 (atomic route) or QM-E06 (aetheric route). Any FTL or frontier node naming QP11 reads the token. Exotic matter is one of several FTL capability primitives that elemental worlds reach by their own account — see FTL in Elemental Worlds (§4) for the full primitive-by-primitive mapping and the atomic-only/elemental-only method pair (D/F). Frontier focuses that are atomic-specific (Nuclear Physics, Quantum Physics) and their elemental mirror (Quintessic Physics) are mutually exclusive per world, selected by FQ9 — a civilisation enters one or the other, never both.

The Deep Reconciliation principle

By the Atomic era, deeper investigation reconnects every world to the shared late tree: the classical elements reveal inner structure; caloric is unmasked as molecular motion after all; the vital force proves to be chemistry of unusual subtlety — or, in these universes, the reverse reduction holds and our physics is the special case. The alternative chains' unlocks persist forever (the Stone keeps transmuting, the Turnings keep turning, the caloric reservoirs stay charged), but late-game content converges. This is not a retreat — it is exactly what happened in our own history when chemistry reduced to physics without invalidating a single reaction. Wrongness at one level is compatible with truth at another, and this principle is what keeps four foundational axes from cascading into a dozen incompatible late-game trees.

Candidate future axes (the framework extends cleanly; each would multiply variety again)

Nature of Light (corpuscular / wave / dual), Luminiferous Aether (real / absent — would derive from the FTL master axis to avoid contradiction), Cosmological Structure (the path to heliocentrism varies even where the destination doesn't), Spontaneous Generation (does life arise from non-life?). Each must first pass the test above — a fact that eventually makes different predictions, not a choice of description — and then needs only a decisive experiment, two or three authored outcomes, a token, and a reconciliation clause.