“Such was the naming system which the Latin grammarians, from Varro in the first century B.C. to Priscian in the sixth A.D., had in mind when defining the technical vocabulary of nomenclature (i.e. praenomen, nomen, cognomen and agnomen). Driven by antiquarian interest and a desire to establish rules they gave the false impression that this was an unaltering archetype, thus encouraging modern commentators to look upon this as the apogee of the Roman naming system and to treat all later developments as decay. However the reality, even in Varro’s day, was somewhat different.”

—Benet Salway, “What’s in a Name? A Survey of Roman Onomastic Practice from c. 700 B.C. to A.D. 700,” The Journal of Roman Studies, Vol. 84 (1994).