f professorships "manuals" have appeared[51] which would
almost make them superfluous were it not that oral instruction, based on
practical exercises, has here an exceptional value. Whether a student
does or does not enjoy the advantage of a regular drilling in an
institution for higher education, he has henceforth no excuse for
remaining in ignorance of those things which he ought to know before
entering upon historical work. There is, in fact, less of this kind of
neglect than there used to be. On this head, the success of the
above-mentioned "manuals," with their rapid succession of editions, is
very significant.[52]

Here, then, we have the future historian armed with the preliminary
knowledge, the neglect of which would have condemned him to
powerlessness or to continual mistakes. We suppose him protected from
the errors without number which have their origin in an imperfect
knowledge of the writing and the language of documents, in ignorance of
previous work and the results obtained by textual criticism; he has an
irreproachable _cognitio cogniti et cognoscendi_. A very optimistic
supposition, by the way, as we are bound to admit. We know but too well
that to have gone through a regular course of "auxiliary sciences," or
to have read attentively the best treatises on bibliography,
palaeography, philology, and so on, or even to have acquired some
personal experience by practical exercises, is not enough to ensure that
a man shall always be well informed, still less to make him infallible.
In the first place, those who have for a long time studied documents of
a given class or of a given period possess, in regard to these,
incommunicable knowledge in virtue of which they are able to deal better
than others with new documents which they may meet with of the same
class or period; nothing can replace the "special erudition" which is
the specialist's reward for hard work.[53] And secondly, specialists
themselves make mistakes: palaeographers must be perpetually on their
guard not to decipher falsely; is there a philologist who has not some
faults of construing on his conscience? Scholars usually well informed
have printed as unedited texts which had already been published, and
have neglected documents it was their business to know. Scholars spend
their lives in incessantly perfecting their "auxiliary" knowledge, which
they rightly regard as never perfect. But all this does not prevent us
from maintaining our hypothesis.