64 EARLY MEDIEVAL SPAINin Visigothic Spain after Isidore and was developed to its greatest
extent by Bishop Ildefonsus of Toledo (657-667), in his book On the
Perpetual Virginity of the Blessed Virgin Mary. It is also to be encountered
in parts of the Visigothic liturgy, where its use is particularly appro-
priate in rhetorical invocatory prayers.
Isidore has also left an important work On the Offices of the Church,
which describes the different services of the Church and their subdi-
visions as they existed in his day in the first book, and the functions
of the different grades of the clergy in the second. The value of this
work for modern canonists and liturgical scholars has been consider-
able. Of a different kind of interest is Isidore's On the Nature of Things
(or The Divisions of Nature), dedicated to King Sisebut (611/12-620),
which studies, in a way that is reminiscent of the later Etymologies and
may well be the inspiration for Sisebut's commissioning that work,
the various phenomena of nature, such as rain, clouds and earth-
quakes, and also the divisions of time. Sisebut used the omission of
the subject of eclipses from Isidore's book to write a poem of his own
on that theme by way of a reply.15
Finally, some ofIsidore's letters have survived, but included amongst
them are a number of forgeries, ranging in date from the later sev-
enth and eighth centuries to the twelfth. The great reputation and
authority of Isidore, both in Spain and beyond, notably in Ireland
and in Gaul, meant that the spurious addition of his name to texts
that were innovatory, but sought the respectability of antiquity or
recognised status of authorship, proved irresistible to forgers. Best
known example of this is the great canonical compilation of the
Carolingian period known as the Pseudo-Isidoran Decretals. As so
many of the letters of the early medieval period take the form of
replies to enquiries concerning issues of Church discipline and or-
der, it was relatively easy to produce pseudonymous epistles making
apparently authoritative pronouncements on points of canon law.
When the spurious ones are removed, the few genuine letters of
Isidore that survive are surprising for their extreme brevity and are
very formal in character, even when addressed to his particular friend
Braulio of Zaragoza. By contrast, the latter's replies are long and
effusive. The greater part of the extant letters of Isidore are exchanges
between himself and Braulio on the subject of the Etymologies, w/lich
the latter was most anxious to read, whereas its author was apparently
most reluctant to let him do so. In reply to one pressing request,
Isidore claimed ingenuously that he was interrupted when beginning