segregated by grade or age. For the socially ambitious, bilingual education in Greek as well as Latin was a must. Quintilian provides the most extensive theory of primary education in Latin literature. According to Quintilian, each child has in-born ingenium, a talent for learning or linguistic intelligence that is ready to be cultivated and sharpened, as evidenced by the young child's ability to memorize and imitate. The child incapable of learning was rare. To Quintilian, ingenium represented a potential best realized in the social setting of school, and he argued against homeschooling. He also recognized the importance of play in child development, and disapproved of corporal punishment because it discouraged love of learning—in contrast to the practice in most Roman primary schools of routinely striking children with a cane (ferula) or birch rod for being slow or disruptive. Secondary education At the age of 14, upperclass males made their rite of passage into adulthood, and began to learn leadership roles in political, religious, and military life through mentoring from a senior member of their family or a family friend. Higher education was provided by grammatici or rhetores. The grammaticus or "grammarian" taught mainly Greek and Latin literature, with history, geography, philosophy or mathematics treated as explications of the text. With the rise of Augustus, contemporary Latin authors such as Virgil and Livy also became part of the curriculum. The rhetor was a teacher of oratory or public speaking. The art of speaking (ars dicendi) was highly prized as a marker of social and intellectual superiority, and eloquentia ("speaking ability, eloquence") was considered the "glue" of a civilized society. Rhetoric was not so much a body of knowledge (though it required a command of references to the literary canon) as it was a mode of expression and decorum that distinguished those who held social power. The ancient model of rhetorical training—"restraint, coolness under pressure, modesty, and good humour"—endured into the 18th century as a Western educational ideal. In Latin, illiteratus (Greek agrammatos) could mean both "unable to read and write" and "lacking in cultural awareness or sophistication." Higher education promoted career advancement, particularly for an equestrian in Imperial service: "eloquence and learning were considered marks of a well-bred man and worthy of reward". The poet Horace, for instance, was given a top-notch education by his father, a prosperous former slave. Urban elites throughout the Empire shared a literary culture embued with