The principle claims there are only two causes of outcomes inside the operating domain of the restaurant. Design and default. That claim is exhaustive. It leaves no room for a third.

Operators resist this claim harder than any other move the principle makes. They want a third cause. They want luck. They want timing. They want the market. They want a bad break. Every operator can list wrong outcomes they believe were not caused by their design or their default. The principle refuses every one of them.

Here is why the claim holds.

A man-made system produces outcomes through human causation. Human causation runs through decisions. Every decision inside the system was made with engineered intent or was not. Decisions made with engineered intent are design. Decisions made without engineered intent — or decisions that were never made at all — are default. That exhausts the cause space at the decision layer.

At the event layer, external forces exist. Weather. Market. Vendors. Regulators. Guests. Cast. Economy. Each of these can present conditions the operator did not choose. But the outcome that follows is not produced by the event. The outcome is produced by the operator’s response to the event, and the response was either designed or defaulted. The event delivered the condition. The response produced the outcome. The response is where the law operates.

At the emergent layer, some outcomes appear to arise from the interaction of many elements over time — a cast culture, a regular clientele, a signature move nobody trained. These outcomes were not designed directly. They were also not defaulted into by a single decision. They emerged from the substrate the operator built or defaulted on. Every substrate traces to design or default at the conditions layer. Emergent outcomes trace to their emergent conditions, and the conditions trace to design or default. The law governs at the conditions layer even when the outcome appears higher up.

At the metaphysical layer, some operators want to invoke luck, fate, or force majeure. The principle rejects each. Luck is what an observer calls the outcome of a design-or-default process they have not examined closely enough. Fate is a story people tell about outcomes after the fact. Force majeure is a legal category, not a causal one — even a hurricane presents conditions the operator either designed against or defaulted toward. None of these categories names a real third cause. Each is a placeholder for a design-or-default read the operator has not yet run.

That is what makes the principle a natural law and not a heuristic. Natural laws have no exceptions. They govern every case in their domain, whether the observer sees the mechanism or not. Newton’s laws govern every falling object whether the observer understands gravity or not. Thermodynamics governs every energy transfer whether the observer understands entropy or not. The Summers Principle governs every outcome inside the operating domain of the restaurant whether the operator understands design and default or not.

If there were a third cause, the principle would be a heuristic. It would work most of the time but not all of the time. Operators could point to the exception cases and file them separately. The framework would be one useful model among many. The claim the principle actually makes is stronger: there is no exception case. Every outcome traces to design or default. The framework is not one model among many. It is the operating physics of the domain.

That is a hard claim. It is also the only claim consistent with the principle being a law. Anything softer than that is a preference, and preferences do not govern outcomes. Laws do.