s original
form, and to ascertain its origin. The first group of preliminary
investigations, bearing upon the writing, the language, the form, the
source, constitutes the special domain of EXTERNAL CRITICISM, or
critical scholarship. Next comes INTERNAL CRITICISM: it endeavours, by
the help of analogies mostly borrowed from general psychology, to
reproduce the mental states through which the author of the document
passed. Knowing what the author of the document has said, we ask (1)
What did he mean? (2) Did he believe what he said? (3) Was he justified
in believing whatever he did believe? This last step brings the document
to a point where it resembles the data of the objective sciences: it
becomes an observation; it only remains to treat it by the methods of
the objective sciences. Every document is valuable precisely to the
extent to which, by the study of its origin, it has been reduced to a
well-made observation.

II. Two conclusions may be drawn from what we have just said: the
extreme complexity and the absolute necessity of Historical Criticism.

Compared with other students the historian is in a very disagreeable
situation. It is not merely that he cannot, as the chemist does, observe
his facts directly; it very rarely happens that the documents which he
is obliged to use represent precise observations. He has at his disposal
none of those systematic records of observations which, in the
established sciences, can and do replace direct observation. He is in
the situation of a chemist who should know a series of experiments only
from the report of his laboratory-boy. The historian is compelled to
turn to account rough and ready reports, such as no man of science
would be content with.[61] All the more necessary are the precautions to
be taken in utilising these documents, the only materials of historical
science. It is evidently most important to eliminate those which are
worthless, and to ascertain the amount of correct observation
represented by those which are left.

All the more necessary, too, are cautions on this subject, because the
natural inclination of the human mind is to take no precautions at all,
and to treat these matters, which really demand the utmost obtainable
precision, with careless laxity. It is true that every one admits the
utility of criticism in theory; but this is just one of those principles
which are more easily admitted than put into practice. Many centuries
and whole eras of bril