"People who are unwilling to make mistakes or have made mistakes and have not yet learned from them are those who wake up each morning and continue to make the same mistakes"

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Pytheos made a mistake by not observing that the arts are each composed of two things, the actual work and the theory of it. One of these, the doing of the work, is proper to men trained in the individual subject, while the other the theory is common to all scholars.

— Marcus Vitruvius Pollio