Every scientific theory must ultimately face the tribunal of experience. The history of science is littered with elegant theories that failed this test — from phlogiston to the luminiferous ether. What distinguishes a theory that survives is not merely its internal consistency, but its capacity to generate testable predictions and, crucially, to survive attempts at falsification. A theory that cannot be falsified is not science; it is metaphysics dressed in the language of empiricism.

Yet the relationship between theory and evidence is rarely so clean. Evidence is itself theory-laden: what we observe depends on the conceptual framework we bring to observation. The history of the telescope illustrates this vividly — Galileo's contemporaries who refused to look were not simply being obstinate. They believed, with some justification, that the instrument introduced distortions that made its evidence unreliable.