When the Royal Society was founded in London in 1660, its members chose a motto that was, for its time, close to scandalous: Nullius in verba — take nobody's word for it. Not the ancients'. Not the church's. Not even each other's. Knowledge would rest on what could be shown, measured, and repeated, and on nothing else. It remains the most productive act of institutionalized disrespect in history.
What the motto founded was not a warehouse of facts but a procedure — a standing agreement to let reality vote last. Hypothesis, test, publication, replication, correction: every stage is a formalized opportunity to be caught in error, entered voluntarily. Scientists are as vain, biased, and career-minded as anyone; the method's genius is that it does not require them to be otherwise. It only requires them to show their work to rivals who would love to find the flaw.
The procedure's power is easiest to see in a single map. In 1854, cholera was killing hundreds in London's Soho, and the reigning theory blamed miasma — bad air. A physician named John Snow walked the streets and marked each death on a map, house by house, and let the pattern speak: the deaths ringed one water pump on Broad Street. The handle came off the pump, and the outbreak with it. Everything was present in that episode — the unfashionable hypothesis, the patient collection of true data, the willingness to let evidence overrule authority — and everything that followed, from sewers to germ theory to the doubling of human life expectancy, is compound interest on moments like it.
Every comfort of the modern world — the vaccine, the transistor, the weather forecast, the anesthetic — is the output of that one cultural decision, renewed daily for four centuries: to care more about what is true than about who said otherwise.