09/04/2026
Leonardo da Vinci wrote this thought in one of his notebooks more than 500 years ago: “Chi non punisce il male, comanda che si facci” —roughly, “He who does not punish evil commands it to be done.”
The familiar English version, “Not to punish evil is equivalent to authorizing it,” comes from a later translation of Leonardo’s writings. It was one of many short observations he recorded on justice, responsibility, morality, and human behavior.
Leonardo is remembered primarily as an artist and inventor, but his surviving notebooks contain thousands of pages exploring everything from anatomy and engineering to philosophy and the nature of human conduct.