“Materialism is a doctrine which, if it were true, would have to be discovered by everybody at the same time; but it is a doctrine which nobody ever discovers at all.”G. K. Chesterton · Ortodoxia · 1908 · capitolul 3
A doctrine nobody lives by instinct cannot be true about people.
Chesterton's argument is a test against common consciousness: a true doctrine about the world should be the most obvious one, accessible to any ordinary person. Yet nobody lives as if matter is everything — everyone fears death, loves, hopes, feels guilt. The mechanism is a reductio applied to real life, not abstract logic. It is like claiming music does not exist while humming all day.
Why it matters It remains useful for testing any ideology: if a doctrine demands people live against what they feel inevitable, it deserves suspicion.