convinced most readers, including Guibert himself, that they were
eye-witnesses of most of the events in their texts.[25] Guibert then
had to deal with the commonplace assumption passed on by Isidore of
Seville:

Apud veteres enim nemo conscribebat historiam, nisi is qui
interfuisset, et ea quae conscribend essent vidisset.[26]

Among the ancients no one wrote history unless he had been present
and had seen the things he was writing about.

To overcome his apparent disadvantage, Guibert offers defense of his
second-hand perspective several times in the course of his
performance.

In the fifth book, immediately after acknowledging the fascination of
what is difficult, Guibert provides two paragraphs on the
difficulties of determining exactly what happened at Antioch. These
paragraphs offer another opportunity to watch Guibert rework material
from an earlier text. The author of the Gesta Francorum had invoked
variation of the topos of humility,[27] just before giving his
account of how Antioch was betrayed by someone inside the city:

I am unable to narrate everything that we did before the city was
captured, because no one who was in these parts, neither cleric nor
laity, could write or narrate entirely what happened. But I shall
tell a little.[28]

When Guibert takes his turn at the topos, he is clearly determined to
outdo the author of the Gesta Francorum, both stylistically and in