Twenty Years to Learn It All

Julius Caesar reports that young Gauls seeking to enter the Druidic order committed themselves to a training period he describes as sometimes lasting as long as twenty years, spent memorizing a very large number of verses covering the whole range of subjects Druids were expected to master, natural philosophy, the movements of the heavenly bodies, the size and shape of the earth, and the power and character of the gods, alongside sacred law and tradition. Oral verse, rather than prose, appears to have functioned as a deliberate memory aid, its rhythm and structure making very large bodies of material easier to hold accurately in the mind across years of repetition and recitation.

Caesar is explicit that Druids were not illiterate. He notes they used the Greek alphabet for ordinary public and private business, making their refusal to write down sacred teaching a considered choice rather than a practical limitation. He offers two reasons the Druids themselves reportedly gave for that choice: first, that they did not wish their doctrine to circulate freely among the common people, and second, that they believed reliance on written notes would weaken a student's memory, since a mind that can always consult a text has less incentive to hold knowledge securely within itself.