Spillways and Downstream Fields Where Benefit and Harm Sit in a Coupled Barrier-Lake Model: Cross-Lake Coupling, Consequence Back-Flow and the Readability–Irreversibility Gradient

Abstract Moral evaluation is usually attached to one place — the act, the agent, or the rules — and the traditions that choose different places argue past one another. This paper uses the barrier-lake model of individual motivation, in which a person’s motivational stock is a lake fed by a need gradient and released on the world through a spillway gate, to locate where an evaluation can attach and what structural facts constrain it. It does not say what is good. A release changes the shared world state, and through it the satisfaction, the channels, the readings, the set points and the synergy of other lakes; its effect on another lake is therefore an edge, and the edge is a vector over five layers, not a sign. Compressing it to a sign requires a value function the dynamics does not supply. Three couplings between lakes are distinguished: satisfaction coupling, in which another’s satisfaction enters one’s own with a positive, negative or zero weight; set-point coupling, in which another’s level enters one’s set point, pairwise or from one common source; and spill coupling through the shared world. Seeing another lake accurately and weighting it positively are two independent axes, and the cell that sees without weighting is the structure of manipulation. Evaluation has four mounts — the edge, the node, the structure and time — which the consequentialist, virtue and contractualist traditions each take for the whole. Across the five layers, the harm becomes less readable by the harmed and, at comparable magnitude, less reversible; the layer also fixes the aggregation operator, so a small harm to a conjunctive function can be total. Three results follow. An evaluation that uses the affected party’s reading is valid only if that reading is owned by the party bearing the consequences and does not pass through the actor’s own reading apparatus; self-reported satisfaction therefore cannot adjudicate harms to readings, set points or synergy, and ownership is relational, which removes a regress. Benefit and harm do not cancel, for three stated mechanisms, and giving confined to satisfaction closes the recipient’s drive without building capability. Concentration moves outward along the multiplicative ray when the allocation exponent rises and returns only if dissipation is supplied, the return carrying hysteresis where concentration feeds its own gain. A consequence back-flow share separates mobile from fixed actors, places the moral boundary of a territorial actor at its back-flow boundary, and explains why migration today changes the water and the channels but not the watchtower. Where readings share one source, harm without any hostile intent becomes the main case. Classical Chinese texts and Western moral philosophy are read as structural counterparts and as sources of open questions, not as evidence. Six predictions are registered, and ten open questions are sorted into those the dynamics can address and those that need a value input.