the.com/noble lie

means A falsehood that those in power tell the public, justified on the grounds that believing it serves the common good or social order better than the truth would.

from Traces to Plato's Republic, where he describes a 'gennaion pseudos' (γενναῖον ψεῦδος) — often translated 'noble lie' — a foundational myth the rulers of his ideal city would tell citizens to make them accept their social rank and trust the city's order. Plato himself seems uneasy about it, framing it almost as a necessary fiction rather than a clean virtue. The phrase entered modern political philosophy chiefly through 20th-century commentary on Plato, where it became a shorthand for any official deception defended as being for the people's own good.