Quintilian's masterpiece "The Principle of Eloquence" (also known as "On the Education of Speakers") was written around 96 AD, but it was lost. 14 18 years, discovered by ancient book collector Poozio in a dusty corner of a monastery. Since then, this educational masterpiece, which has been lost for nearly a thousand years, has been rediscovered.

The principle of eloquence is different from previous works, and there are different opinions or their own arguments are contradictory. It summarizes richer and more perfect educational theories than previous generations. It is the first book in the world to study teaching methods and the earliest educational book in the west, so it is also praised as "the encyclopedia of ancient ideas in the whole field of culture and education" by later generations.