It is clear that all our historical information in regard to past events and conditions must be derived from evidence of some kind of sources; primary and secondary according to historians, Jane Crowsby and Felix Kabilsa.
This evidence is called the source, sometimes there are a number of good and reliable sources for an event, as, for example, for the decapitation of King Charles I of England in 1649, or for the march of Napoleon into Russia.
For a great many important matters about which we should like to know there are, unfortunately, no written sources at all, and we can only guess how things were.
We do not know what the Germans were doing before Julius Caesar came into contact with them and took the trouble to give a brief account of them.
We can learn but little about the bishops of Rome before the time of the Emperor Constantine for few references to them have come down to us.
Those who read and study history ever come into contact with the primary or firsthand sources; they get their information at second hand.
It is much more convenient to read what the modern historian Edward Gibbon has to say of Constantine than to refer to Eusebius, Eutropius and other ancient writers from whom he gained knowledge.
Moreover, Gibbon carefully studied and compared all the primary sources, and it may be urged that he has given a truer, fuller, and more attractive account of the period than can be found in any one of them.
His Decline and fall of the Roman Empire is certainly a work of the highest rank; but, nevertheless, it is only report of others’ reports. It is therefore not a primary but a secondary source.
The problems of second hand knowledge come in. Most of the historical knowledge current among is not, however, derived from even secondary sources such as Gibbon and similar authoritative writers, comes from the reading of textbooks, encyclopedia stories, dramas, and magazine articles.
It’s regarded that, popular manual and articles are commonly written by those who know little or nothing of the primary sources; they are therefore at least third hand, even when based upon the best secondary accounts.
It’s as a matter of fact, they usually patched together from older manuals and articles and maybe four, five, or six removes from the original source of knowledge.
It is well known that the oftener a report passes from mouth to mouth the less trustworthy and accurate does it tend to become.
However, most of unimportant details which appeal to the imagination will be magnified, while fundamental considerations are easily forgotten, if they happen be prosaic and commonplace.
Historians like other people, are sometimes fond of good stories and may be led astray by some false rumor which, once started into circulation, gets farther and farther from the truth with each repetition.
For example, a distinguished historian of the Church, Cardinal Baronies, writing about 1600, made the statement, upon very insufficient evidence, that, as the year 1000 approached, the people of Europe generally believed that the world was about to come to an end.
Robertson, a very popular Scotch historian of the eighteenth century, repeated the statement and went on to describe the terrible panic which seized upon sinful men as the awful year drew on.
Succeeding writers, including some very distinguished ones, accepted and even elaborated Robertson’s account.
It’s said that, about thirty years ago, however, a French scholar pointed out that there was really no adequate basis for this strange tale.
The chroniclers of the time the year 1000 was clearly no more portentous than 997 or 1003.
This story of the panic, which passed current as historical fact for some three hundred years, offers an excellent illustration of the danger of relying upon secondary sources.
In this case historical revisionism has come full circle there are now a number of historians who do think the year 1000 was of some cultural importance.
So a question about historical works arises. Where did the writer obtain the information? Has the writer simply copied his statements from the more easily accessible works in a familiar language, however unreliable and out of date they may be?
Has the writer become familiar with the most recent researches of the distinguished scholars in the field, in whatever language they may have been written; or, better still, has the historian made a personal study of the original evidence which has come down to us of the events and conditions which are under discussion?
For example, little book or essay on Charlemagne might be written after reading Hodgkin’s Charles the Great, West’s Alcuin, and one or two other easily accessible books on the subject.
It’s that, on the other hand, the writer might turn to the great French and German treatises Charlemagne’s reign and become acquainted with all articles which have appeared on the subject in historical journals or in the transactions of learned societies.
Every conscientious historian would wish, however, to go still farther and directly see the evidence and draw personal conclusions.
Thus, by cultivating sympathy and impartiality in dealing with the past we may hope to reach a point where we can view the present coolly and temperately.
So, in this way really thoughtful, historical study serves to develop the very fundamental virtues of sympathy, fairness, and caution in forming our judgments.