On the Education of Speakers, also known as the Principle of Eloquence, is the earliest book devoted to education in the West, and is also known as the first teaching method book in ancient West. Quintilian's systematic exposition of high, middle and primary education and preschool education is called the highest achievement of ancient European education theory and development.

This book discusses the training and education methods of speakers in detail and is regarded as a classic of western pedagogy. In his book, quintilian emphasized the systematicness and practicality of education, and put forward many educational thoughts that are still instructive today.