When empiricism is out of reach, run a disciplined counterfactual: one isolated change, fixed conditions, step-by-step mechanism, and a hard bound on implications.
Emit a thought-experiment record:
question: what behavior or decision is under testisolated_variable: single change vs control worldinitial_conditions: frozen state and non-changesconsequence_chain: ordered mechanistic stepsinvariants: what still holdsbreak_points: first requirement failures and critical assumptionsimplication_bound: actions/checks justified by the chain onlydiscriminating_check: cheapest real observation to confirm or kill the weak link