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. 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 brilliant civilisation had to pass away before the first dawn of criticism was visible among the most intellectual peoples in the world. Neither the orientals nor the middle ages ever formed a definite conception of it. Up to our own day there have been enlightened men who, in employing documents for the purpose of writing history, have neglected the most elementary precautions, and unconsciously assumed false generalisations. Even now most young students would, if left to themselves, fall into the old errors. For criticism is antagonistic to the normal