Plato's Dialogues.

"That Plato should be the first of all the ancient philosophers to be translated and broadcast by the printing press was inevitable. Plato’s central conception of a universe of ideas, Perfect Types, of which material objects are imperfect forms, and his ethical code based on action according to human nature, developed by education, which represents the authority of the State, fitted in as well with the philosophical, religious and political thought of western Europe in the 15th century, striving to free itself from the shackles of scholasticism, as it did with those of the Byzantine Greeks, by whom Plato was repopularized in the western world The dialogues are pervaded by two dominant impulses: a love of truth and a passion for human improvement" (PMM 27).