In 1847, a Hungarian physician named Ignaz Semmelweis noticed a fact nobody wanted: mothers in the Vienna maternity clinic staffed by doctors were dying of childbed fever at far higher rates than those attended by midwives — and the doctors were coming straight from autopsies. When he made handwashing in chlorinated lime mandatory, mortality in his clinic fell from roughly one death in five to about two percent within months. The medical establishment's response was to ridicule him. The truth was inconvenient; it implied that the healers' own hands had been the vector. Semmelweis died in an asylum in 1865, disgraced. The germ theory that vindicated him arrived within a generation, too late for him and for thousands of mothers.
Medicine's entire modern history is the story of building machinery to stop that from happening again: controlled trials, peer review, mandatory adverse-event reporting, retraction. None of it is decoration. A clinical trial is simply an elaborate device for forcing an honest answer to the question does this treatment work? — designed, double-blinded, precisely because the people asking cannot be trusted to want the true answer.
The machinery matters because the failures are not hypothetical. In 1998, a paper in The Lancet claimed a link between the MMR vaccine and autism. It took twelve years for the fraud to be fully exposed and the paper retracted, and its lead author was struck from the U.K. medical register — but the falsehood had already escaped into the world, where it still suppresses vaccination rates and still costs lives in measles outbreaks decades later. A lie in a dataset does not stay in the dataset.
This is the argument for truth at its most literal: when the data is honest, strangers you will never meet get to live. Every prescription filled today is an act of trust in an unbroken chain of people who reported what they actually measured. Break the chain anywhere and the medicine stops working — not chemically, but in the only sense that counts: nobody can know if it works.