THE METHOD 5incere 5cience

We formalize the Untested Possibility Principle (UPP): when a phenomenon admits exactly two logically exhaustive explanations and the scientific community has invested decades or centuries pursuing one of them without complete closure, the resolution is likely to lie in the other. The principle is not a theorem but a heuristic of logical audit. Its force is not to prove the neglected possibility correct—this still requires evidence—but to identify that the neglected possibility exists, that it has not been refuted but merely not pursued, and that the resulting investment asymmetry must be corrected before any conclusion can be considered settled. The UPP rests on two pillars: (i) logical exhaustiveness, which guarantees that the failure of one possibility implies, by elimination, the correctness of the other or the misformulation of the problem; (ii) investment asymmetry, which recognizes that scientific communities are social systems and that the absence of evidence against a neglected hypothesis is not evidence of its absence—it is evidence that no one looked. The UPP is not Popper, not Kuhn, not Lakatos, not Feyerabend. It operates one step earlier than any of them. Before asking whether a research program is falsifiable, degenerative, or revolutionary, the UPP asks whether the direction opposite to the chosen one was ever tested at all. This is a question that can be answered by logic alone, prior to any empirical commitment, and which therefore costs nothing to ask but exposes everything when the answer is no. We anchor the UPP in the epistemological hierarchy formalized in the Mummification of General Relativity (Part 0F, Ontological Ceiling) [1]: Philosophy ↔ Logic (L1) generates Theory ↔ Mathematics (L2); ontological advance is constitutively impossible from within L2 alone; the UPP is the operational tool of L1. We further show that within L1 itself an order obtains: philosophy must exhaust the possibility space before logic operates upon it. Skipping that step—collapsing it with a statistical induction—contaminates every theory and equation that follows. The UPP, in its binary form, is one instance of this more general philosophical-exhaustion requirement. We walk through seven canonical cases drawn from biology, physics, thermodynamics, medicine, and cosmology. In each, the structure is identical: two possibilities exist, one was institutionalized, the other was never tested, and the neglected possibility resolves anomalies that the institutionalized one accumulated for decades. We close with a self-assessment: the UPP meets the criteria it demands of the frameworks it audits. It declares the conditions under which it fails. It is falsifiable in application. A principle that could not be wrong would be a tautology. The UPP is not.