Men will have pomp and mystery surrounding important things, and therefore the historians must, consciously or unconsciously, tend to strut, to quote solemn authorities in support, and to make out the vulgar unworthy of their confidence. Hence, by the way, the plague of footnotes.
These had their origin in two sources: the desire to show that one was honest and to prove it by a reference; the desire to elucidate some point which it was not easy to elucidate in the text itself without making the sentence too elaborate and clumsy. Either use may be seen at its best in Gibbon. With the last generation they have served mainly, and sometimes merely, for ritual adornment and terror, not to make clearer or more honest, but to deceive. Thus Taine in his monstrously false history of the Revolution revels in footnotes; you have but to examine a batch of them with care to turn them completely against his own conclusions--they are only put there as a sort of spiked paling to warn off trespassers. Or, again, M. Thibaut, who writes under the name of "Anatole France," gives footnotes by the score in his romance of Joan of Arc, apparently not even caring to examine whether they so much as refer to his text, let alone support it. They seem to have been done by contract.
Belloc, On Historical Evidence, First and Last. Spiked palings and contracted footnotes are, alas, too common still today. By the way, although the book is a delightful read, the best sketch in the book, and the one that everyone should read, is The End of the World.