He is talking to graduating scientists about a kind of research that has the forms of science and not the integrity: the cargo cult, building the runway and waiting for the planes. The principle is not a joke about other people’s stupidity. The easiest person to fool is the speaker, the experimenter, the author of a quotationary. He wants a bending over backwards to show yourself how you might be wrong. The address is the best short ethics of knowledge written in the century.