Biology and medicine often mistake complexity for understanding. We build black-box AI models and amass terabytes of omics, yet the logic of life remains hidden in plain sight. Cells, the smallest decision-makers, compute not probabilistically, but logically: “on” or “off,” “commit” or “retract.” Boolean mathematics decodes this digital behavior, distilling molecular noise into invariant “if–then” rules that persist across tissues, species, and diseases. By quantifying how populations shift between binary states, Boolean logic maps disease as an analog continuum—dynamic, graded, reversible and measurable. By formalizing a framework that has long existed but unnamed, we introduce AXIOM-Bio (Abstract eXpression Inference and Ontology-free Modeling for Biological Logic and Disease): a platform that replaces static biomarkers with mechanistic rules, advancing a new premise, if life computes in logic, medicine should too.