Quote by Richard Feynman: “The first principle is that you must not fool yourself — and you are the easiest person to fool.”

Self-deception is the most dangerous kind of dishonesty because you cannot see it happening. Before you can understand the world honestly, you have to be ruthlessly honest with yourself — and that is genuinely harder than it sounds.

Feynman delivered this in his 1974 Caltech commencement address titled 'Cargo Cult Science.' The speech came during an era when public trust in institutions was shaken by Watergate and the Vietnam War, making scientific integrity and honest self-examination especially resonant themes.

American theoretical physicist and Nobel laureate known for his work in quantum electrodynamics and his remarkable ability to explain complex science to general audiences. His 1985 memoir Surely You're Joking, Mr. Feynman made him one of the most beloved scientists of the twentieth century.