Causation

You read strike-and-flame as one connected event. You did not stop to check the metaphysics first.

Try to deny causation. The denial is a record made under causal conditions — a hand on a key, a letter in a sentence, a sentence reaching a reader. There is no ground from which causation can be denied without using it.

Hume looked at the strike and the flame and reported what he saw. Strike, then flame. Many times. Always in that order. He did not see a binding force. He saw constant conjunction. The mind supplied the connection. The world contained the regularity.

He saw something real. No logical necessity binds the strike to the flame. You can imagine the strike without the flame. There is no logical glue between events.

What regularity cannot do is everything else. It cannot tell causes from accidents — day follows night, but night does not cause day. It cannot ground if you had not struck it, it would not have lit. It cannot handle two assassins, where the first bullet kills and the second would have.

The second family says causation is more than sequence. Powers. Necessitation. Mackie’s careful logic: the strike is an insufficient but necessary part of an unnecessary but sufficient set — oxygen, dry compound, friction, temperature. Lewis’s counterfactuals: A causes B if, in the closest world where A does not happen, B does not either. Precise, and paid for with real possible worlds.

This family is right that because is not and then. What none of its versions says is what the connection is. A force is posited and left blank. A logical structure is described without saying what holds it. Counterfactuals get truth-conditions at the price of an extravagant ontology.

Regularity sees no connection and concludes there is none. The second family sees more than sequence and never names it.

A cause is a record written at one site that, through bounded propagation, alters the trajectory-space at another site.

The strike writes a record — friction, heat, ignition temperature reached. The record propagates at the rate C permits, across the head, into the air, through the molecular interactions of combustion. At the flame site, what the substrate permits next has been altered. The flame trajectory is open. The unlit trajectory is foreclosed.

No connection was added. The propagation was the connection.

C did the work. C is the connection. The steps are in the original, Chapter Five. Check them there.

Causation is not a fifth condition. It is C, read at the layer where one record changes another.

Hume is preserved and relocated. No logical necessity. But not nothing either. The connection is structural. Bounded rate. Determinate path. Constraint on what follows what. Structural necessity is enough, because the substrate does not run on logic. It runs on the four conditions.

One distinction, so the hard cases fall.

In the world, the causal structure of the flame includes the strike, the oxygen, the dryness, the friction, the temperature, the chemical bonds. All of it is one propagation network.

In explanation, a reader picks one part of that network and names it the cause, relative to a contrast. Why the flame? The strike — as against an unstruck match. Why this time? The dryness — as against yesterday’s damp match. Why this surface? The friction.

The connection is C-propagation in every case. What varies is the selection.

Pre-emption. Two assassins. The first bullet kills. The cause is the chain whose record actually propagated into the death. The second chain is a counterfactual threat — it would have written the record had conditions differed. It did not.

Overdetermination. Two bullets arrive together. The record contains both chains. Did this assassin cause the death? Yes. The other? Also yes. Was either necessary? No. The network tolerates both. The explanatory question chooses what to name.

These are the cases that defeated regularity and simple counterfactuals. They fall here because the connection is propagation, and a propagation network can carry several chains at once.

And the had to. Given the right conditions, the same strike always lights. That is structural determinacy, not logical necessity. Same conditions, same propagation. A damp match, a vacuum — different conditions, different propagation.

One precision first. At the physical floor, C is the vacuum limit. Sound in air, a reaction front, a wave on water are not extra Cs. They are C filtered through structured media. Institutional and social propagation are different in kind — they run on top of physical propagation, at rates set by how the structures are organised, and physical C bounds every signal in the chain.

A vote. A mark on a ballot propagates through counting, certification, announcement, policy. Never instantly. Slow, because of how the institutional layer is built. Record at A, trajectory-space altered at B.

A stone in water. The surface deforms at the impact and the ripple spreads at the rate water can carry it. The wave does not jump to the bank.

A photon from a star. An electronic transition writes a record that travels at the vacuum limit for fourteen billion years, through lensing, dust and atmosphere, into a detector. Every step within what C permits.

One form. Record written. Propagated at the rate C permits at that resolution. Trajectory-space altered where it lands.

That C bounds all causal propagation is not assertion. It is measured.

Einstein, 1905. Every observer measures the same c, whatever their motion. From that, with the principle of relativity, follows the whole structure — dilation, contraction, the invariant interval, and the light cone. At every event, a forward cone of what it can reach and a backward cone of what could have reached it. Events outside both cannot be in causal contact, whatever their order in some frame.

The light cone is the geometric form C takes at the relativistic layer. Cosmic rays, accelerators, GPS, gravitational waves — every one is a measurement of C’s status. None has ever found a record-bearing influence outside the cone.

Relativity also sharpens the identity claim that follows. Causal order is the invariant part of temporal order. Inside each other’s cones, all observers agree who came first. Outside, there is no causal arrow to identify with time. The identity applies where causal connection is structurally available.

Smoking causes lung cancer, and not every smoker gets it. The strike causes the flame, every time under the same conditions.

Not two kinds of causation. One form under two conditions at the receiving site. Deterministic: the propagation opens one trajectory and forecloses the rest. Probabilistic: the propagation shifts the weights across many trajectories without forcing one. Smoking writes records at the cellular layer over years, and at certain sites the cancer trajectories gain weight. Both are C-propagation. Altering trajectory-space is not restricted to forcing an outcome.

Cause to effect, never the reverse. Past to future, never the reverse.

One arrow. Two names, because it is read from two positions.

From inside a propagation, the earlier record constrains the later. That is causation. From across many propagations at once, earlier records sit on the past side and later ones on the future side. That is time.

Both are R. Records do not unwrite. That is why cause and effect cannot be reversed, and it is the same reason past and future cannot.

The philosopher presses. Cause and effect is local. Past and future is global. — Local and global are reading positions, not different structures.

Another presses. One arrow must be fundamental and the other derived. — There is no priority, because there are not two arrows.

The block-universe reader presses. Past, present and future are equally real; the now is a perspective. — Keep the four-dimensional description. What cannot be dropped is R. Without it the manifold is an unordered set, not a history. With it the manifold has direction, and that direction is the one arrow.

The axiom excludes strong backward causation — a later event unwriting an already-written earlier record. That is R.

The mechanical laws are time-symmetric. — They describe what is dynamically permitted. R describes the direction under which anything actually happens. Running the film backwards in the equations is not unwriting a record in the substrate.

Tachyons. — None carrying record-bearing influence has ever been observed. Where such fields appear in the formalism they mark an unstable point. Observe one and RES-5.5 fires.

Time-symmetric formulations. — They describe both directions the equations can be read. R describes the direction the substrate writes. Different layers.

Retrocausal interpretations, where a measurement now shapes a state prepared earlier. — The strongest forms are in real tension with R and are not dispatched. Whether they require unwriting a written record is open, and carried to Chapter Eight and the physics papers. The account holds for every version that does not.

The most robust non-classical fact in the world. Two particles prepared together, separated, measured. The outcomes correlate in ways no local hidden-variable theory can produce. Bell proved it in 1964. Aspect, Hensen and the 2022 Nobel work confirmed it.

A naive reading would fire RES-5.5. Measuring here fixes the result there, instantly.

That is not what the physics says. The no-communication theorem: no signal, no controllable information, crosses between the sites faster than C. The correlation appears only when the results are brought together, by ordinary communication that respects C.

Structurally, the two measurements are not record-propagation between sites at all. The joint preparation established one non-factorisable constraint-structure — not two pre-written local outcomes, which Bell rules out, but one structure that cannot be split into two independent local ones. The measurements are coordinated readings of it. Nothing travels between them.

C-respecting, because nothing propagates faster than C. R-respecting, because the constraint was written at preparation and the measurements read what it constrained.

Non-locality in the correlations. Not in any signal. RES-5.5 does not fire.

If you had not struck the match, it would not have lit.

Lewis grounded that in real possible worlds. Not needed. A counterfactual is a constraint on counterfactual trajectory-space. Remove the strike-record and the chain that opened the flame trajectory goes with it. The cause is the record whose removal changes the space. The same axiom runs on the varied conditions. C does not bend. R does not fail. Which variations are well-formed is Chapter Eight.

Quantum measurement — the physics papers. Mental causation — no separate kind; propagation at the resolution where mental states are records. Social causation — same form, larger structures. Omission — not watering the plant caused its death only relative to a viability-structure in which watering kept the living trajectory open. Absences are missing sustaining records, not ghost causes. Which absence gets named is an explanatory policy.