The handling of historical sources and of history in general can be manifold: sources and documents can serve to support one’s own world view with seemingly objective evidence, they can be used to gain attention with lurid theses or to pursue a political agenda, one can also study them for their own sake in order to find out “how it really was” as impartially as possible. Only the last attitude is scientific in the fullest sense if science means a commitment to knowledge of truth in all its differentiation and multi-perspectivity. The safeguarding of one’s own worldview tends to select from the multi-layered historical material that which fits best into the preconceived concept, and to disregard others altogether. Similarly, the action-guiding interest for attention or of strategic discourses selects the documents that seem most appropriate for achieving the goal and suppresses others that are contrary to it. Approaching the ideal of understanding “how it really was,” on the other hand, succeeds only if all accessible sources are actually made to “bubble up.” And even then, some additional qualitative criteria are needed, as the history of historical research shows.

Critical Evaluation of Sources

Herodotus of Halicarnassus, a Greek writer of the 5th century BC, is considered the “father of historiography” (Cicero: De legibus I 5). Tradition relates that he undertook several extensive journeys and did something like research of the source. At least that is what he claims in his nine-volume work “Histories”. Despite this claim, Herodotus sometimes had a strikingly uncritical relationship with his sources and informants. In the third book of the Histories, for example, he reported of Indian ants that are “not as big as dogs, but bigger than foxes” and who dig up gold-bearing sand from the bowels of the earth (Histories III, 102). Likewise, he testified to have found Arabian sheep whose tails are “at least three cubits long” so that the shepherds, in order to avoid chafing of the tails, tie them to little wagons that the sheep pull behind them (Histories III, 113). Even in antiquity, people were offended by these fanciful reports, which may have been lurid but do not paint a credible picture of the real conditions.

Therefore, Herodotus may have written down history and stories, but he was probably not a precise and critically examining historian. Only a generation later Thucydides claims to have been a historian when he writes the history of the Peloponnesian War and clearly distances himself from Herodotus’ approach: “What actually happened in the war, however, I did not allow myself to write down according to the first-hand information, nor ‘according to my own opinion'” – a phrase Herodotus used again and again – “but I followed my own experience and news from others with all possible accuracy (akribeia) down to the last detail” (Thucydides I, 22). It is the greatest possible accuracy, the meticulousness (akribeia), that distinguishes a historian from a mere storyteller. Good historical research does not simply rely on statements, but carefully examines its sources, getting to the bottom of all attainable details.

Unbiased Objectivity

At the beginning of his historical work on the early Roman imperial period (the so-called “Annals”) Tacitus mentions moral impartiality as a second principle of good historical research: “The deeds of Tiberius and Caligula, as well as of Claudius and Nero, were falsified out of fear during their lifetimes, and described with fresh hatred after their deaths” (Annals I, 1). Both approaches distort and disfigure the historical truth beyond recognition. Therefore, Tacitus takes it upon himself “sine ira et studio – without anger and zeal” to evaluate the sources purely factually and to write about it. However, this does not mean that Tacitus levels specifics or even trivializes misdeeds. On the contrary, it is precisely through the factual exposition of the manifold motives, character traits, and modes of action that the historical persons gain their sharp profile, which sometimes includes contradictions. The historian, however, does not impose his moral judgment on posterity, but leaves it to the reader to make up his own mind.

The Other Side Should Also Be Heard

Closely related to this basic attitude is another one described by Seneca as follows: “Whoever passes judgment without hearing the other side has done wrong, even if his judgment were just” (Medea 199-200). The principle addressed here, “audiatur et altera pars – the other side should also be heard,” is not only a legal principle, but a hallmark of good scholarly practice in historical research. Despite its connection with the principle of impartiality mentioned in second place, this basic attitude goes beyond the demand that a historian should withhold his moral judgment: anyone who does not even allow the other side to have its say commits an injustice, because history is thus reduced to a one-dimensional story line. Such an approach cannot, in principle, do justice to the historical complexity.

The authors quoted were, it should be emphasized, not scientists in the modern sense. However, with the principles of precise examination of sources, impartiality oriented to the matter at hand, and the right of each side to be heard, they have formulated principles behind which good scientific practice in historical science and its auxiliary sciences must not fall back. This is the standard by which good historical research, regardless of which side it is conducted, must be measured today.