This perversion of rhetorical theory in the middle ages and early
renaissance had resulted not from mere wrong-headedness on the part of the
rhetoricians, but from the limited knowledge of classical tradition during
the middle ages. Especially was this true in those parts of western
Europe, such as England, which were remote from the Mediterranean
countries which better preserved the heritage of Greece and Rome.
Moreover, the most important classical treatises on the theory of
poetry--by Aristotle and Longinus--were almost unknown throughout the
middle ages, and the rhetorical writings of Cicero and Quintilian were
known only in fragments.

Servatus Lupus (805-862), Abbot of Ferrieres and a learned man, was
unusual in his scholarship; for he knew not only the rhetoric _Ad
Herennium_ which was believed to be Cicero's but also the _De oratore_ and
fragments of Quintilian.[155] The current rhetorical treatises of the
middle ages were Cicero's _De inventione_, and the _Ad Herennium._ The _De
oratore_ was used but slightly, and the _Brutus_ and the _Orator_ not at
all.[156] What little classical rhetoric there is in Stephen Hawes was
derived from the _Ad Herennium_.

The survival and popularity of the _Ad Herennium_ during this period is
one of the most interesting phenomena of rhetorical history. Of the
classical treatises on rhetoric which survive to-day it undoubtedly
arouses the least interest and can contribute the least to modern
education or criticism. Yet it is the most characteristic Latin rhetoric
we possess. It is a text-book of rhetoric which was used in the Roman
schools. In fact, Cicero's _De inventione_ is so much like it that some
suspect that Cicero's notes which he took in school got into circulation