Or "let them give light to the world". An allusion to Isaiah 6.3: plena est omnis terra gloria eius ("the whole earth is full of his glory"). Sometimes mistranslated as "they will illuminate the lands" based on mistaking irradiare for a future indicative third-conjugation verb, whereas it is actually a present subjunctive first-conjugation verb. Motto of Amherst College; the college's original mission was to educate young men to serve God.
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