​Chapter 6

John was left at the table, and the argument since has been about laws and what certifies a claim as causal. The two meet in an assumption carried along without examination: that whatever ran in John ran the way causation runs between bodies. It is the determinist's to defend, and he defends it in a stronger form than the one usually attributed to him.

Motives entail no deed, and the determinist says so before anyone can say it to him. From "the pawnbroker is repulsive" and "there is an axe in the porter's lodge" no deed follows; from "the stone was thrown" no falling follows either, and a world where the thrown stone hovers can be described without contradiction. Logical entailment was never where the necessity was supposed to sit. "He stole from hunger" is not what he defends.

Thinking runs under no rigid logical rule. A man can hold two contradictory things and act on the second, or draw the conclusion his premises forbid, or refuse the conclusion they compel and lose nothing he needs — and none of it stops him from thinking. Logic can be dropped mid-course and the course continues. A motive answers a question the physical vocabulary has no place for: it speaks in favor, and it survives the follow-up "and what for," which the falling stone cannot be asked at all. The transfer of causal necessity into thought has to be argued for, and the shorthand of motives supplies no ground for it.

The determinist defends a state and a set of laws. The complete condition of John and the world, together with the laws, permits a single continuation; the hunger named in the shorthand is a coarse summary of a small part of that condition. Bring him a second man, equally hungry, who walked away, and nothing is dented — the states differed, in memory, in whatever the second man had eaten, and "equally hungry" was a description that discarded almost everything.

Take John's state at the completeness the determinist requires. It contains the neutrino passing through John's chest, the coffee drunk at four, the atmospheric pressure in the room, the count of cells that died since morning, the DNA and every error copied into it. It has to contain them: what fixes the outcome must include whatever could have borne on the outcome, and a state permitting a single continuation cannot leave anything out on the grounds that it seemed small.

A condition of that kind occurs once. Its uniqueness owes nothing to the coarseness of instruments, and a perfect recorder would change none of it — the neutrino passed once, the coffee was drunk once, and this configuration of John and the world will not recur. The more fully a state is specified, the more securely it belongs to a single moment: completeness manufactures the singularity.

Causal claims are recognized by patterns outlasting the case. A law connects states of a type; a mechanism decomposes a transition into stages, and each stage claims that this kind of thing leads reproducibly to that kind; intervention reports a difference stable across trials. Even where outcomes scatter, the distribution holds steady and that carries the claim.

The complete state falls under types without limit, which is what makes physics possible: the stone has a mass, a density, a temperature, a moment of inertia, and every one of them is shared with countless other stones. What no type supplies is the state in its completeness. A law reaches the case through a model, and the model was built by discarding — the stone becomes a point mass, the air is set aside, the crystal structure never enters. Prediction succeeds in the measure that what was discarded stays irrelevant.

Complexity is where the measure runs out gradually. A drug tested to the highest standard helps this patient and fails that one with the same diagnosis, and the trial holds at the population while the ward remains uncertain. Psychology loses its grip earlier, its constructs coarser and its intervals wider. John is the far end of the same series: an unfired neuron, a hundredth of a degree, a night of poor sleep can in principle bear on how the question closes, and a model of him has thrown all of it away. The model reaches him only by ceasing to be a model.

The determinist answers that the laws are general and the state is singular, so the generality he needs is in place. Applying a law to this state requires subsuming the state under the type the law connects, and the subsumption is the discarding. Generality is purchased with the operation that costs him the outcome, and he cannot hold the fullness and the form in the same hand. Each is required for a different half of his claim.

Nor is the fullness available to be written down. A recorder complete enough to fix the state would be part of the state it fixed, and the record would arrive describing a different case from the one it was built to catch.

What he can establish — hungry men take more often, men raised in that church take less often — is reproducible, testable, and true, and it fixes nothing about the case of John. What would fix this is unrepeatable and meets no criterion by which a causal claim is ever certified.

The determinist keeps two currencies in Raskolnikov's case and pays in whichever is convenient. Conviction comes from the coarse things — an axe, a sister marrying for money, an old woman who is rich and repulsive — and these are what the prosecutor works with, what the reader follows, and what any judgment of a man is made of. The obligation is written against the complete state, where the axe and the sister dissolve into a configuration nobody has and nobody will produce. Confidence is drawn on the abstraction and the debt is booked to the unrepeatable.

Place the settling under a reproducible form and the claim becomes that cases of this kind close this way. What remains under the description is a rate.