"How many parts of speech are there?" "Eight."
"What are they?" "Noun, pronoun, verb, adverb, participle,
conjunction, preposition, and interjection."
"What is a noun?" "A part of speech with case, signifying a
body or thing particularly or commonly."
"How many attributes have nouns?" "Six."
"What are they?" "Quality, comparison, gender, number, figure, case."
Etc., etc.
[5] The following from Priscian, reproduced by Graves, illustrates the method of instruction as applied to the first book of the Aeneid of Vergil.
"What part of speech is arma?" "A noun."
"Of what sort?" "Common."
"Of what class?" "Abstract."
"Of what gender?" "Neuter."
"Why neuter?" "Because all nouns whose plurals
end in a are neuter."
"Why is not the singular used?" "Because this noun expresses many
different things."
Etc., etc.
This form of textbook writing was common, not only during the Middle Ages, but well into modern times. The famous New England Primer was in part in this form, and many early American textbooks in history and geography were written after this plan.
[6] Vergil, due to his beautiful poetic form and to his love of nature and life, was especially guarded against during the early Middle Ages as the most seductive of the ancient Latin writers. It is not at all inappropriate that, in Dante's Inferno, Vergil should have been the person to guide Dante through hell and purgatory, but should not have been allowed to accompany him into paradise.