Science Quote by Arthur Eddington

Newton's First Law arrives in textbooks like a granite slab: absolute, clean, and smugly final. Eddington cracks it with a single, mischievous hinge clause: "except insofar as it doesn't". The joke isn't that inertia is wrong; it's that the law's apparent certainty depends on a quiet pile of footnotes we usually pretend aren't there. In real physics, "a body" is never just a body, "uniform motion" is never perfectly uniform, and "straight line" is a geometric fantasy unless you specify a frame, ignore friction, and quarantine the rest of the universe.

Eddington, a scientist with a philosopher's ear for what language hides, is needling the way scientific laws get rhetorically upgraded from models to metaphysical facts. That final phrase mimics the legalistic carve-out in contracts, reminding you that the power of a law is partly performative: it declares order, then survives by admitting exceptions as "external forces". The subtext is epistemic humility with teeth. Scientists aren't priests of certainty; they're managers of approximation.

Context matters here: Eddington worked at the moment when relativity was publicly unsettling "common sense" physics. He spent his career translating technical revolutions for lay audiences, and this line reads like pedagogy by puncture wound. It teaches you to respect laws without worshipping them, and to notice how much of science is conditional: true in the ideal case, useful in the messy one, honest only if you keep the asterisks attached.