We may advance a step farther. In themselves conceptions are nothing but facts in psychology; but imagination does not create its objects, it takes the elements of them from reality. Descriptions of imaginary facts are constructed out of the real facts which the author has observed in his experience. These elements of knowledge, the raw material of the imaginary description, may be sought for and isolated. In dealing with periods and with cla.s.ses of facts for which doc.u.ments are rare--antiquity, for example, and the usages of private life--the attempt has been made to lay under contribution works of literature, epic poems, novels, plays.[168] The method is legitimate, but only within the limits of certain restrictions which one is very apt to forget.
(1) It does not apply to social facts of a psychological order, the moral or artistic standards of a society; the moral and aesthetic conceptions in a doc.u.ment give at most the individual standards of the author; we have no right to conclude from these to the morals or the aesthetic tastes of the age. We must at least wait till we have compared several different authors of the same period.
(2) Descriptions even of physical facts and objects may be products of the author"s imagination. It is only the _elements_ of them which we know to be certainly real; all that we can a.s.sert is the separate existence of the irreducible elements, form, material, colour, number.
When the poet speaks of golden gates or silver bucklers, we cannot infer that golden gates and silver bucklers ever existed in reality; nothing is certain beyond the separate existence of gates, bucklers, gold, and silver. The a.n.a.lysis must therefore be carried to the point of distinguishing those elements which the author must necessarily have taken from experience: objects, their purpose, ordinary actions.
(3) The conception of an object or an action proves that it existed, but not that it was common; the object or action may have been unique, or restricted to a very small circle; poets and novelists are fond of taking their models from an exceptional world.
(4) The facts yielded by this method are not localised in s.p.a.ce or time; the author may have taken them from a time or country not his own.
All these restrictions may be summarised as follows: before drawing any inference from a work of literature as to the state of the society in which the author lived, we should ask ourselves what would be the worth of a similar inference as to contemporary manners drawn from a modern novel.
With the facts yielded by conceptions we may join those indifferent facts of an obvious and elementary character which the author has stated almost without thinking. Logically we have no right to call them certain, for we do sometimes meet with men who make mistakes about obvious and elementary facts, and others who lie even on indifferent matters. But such cases are so rare that there is not much danger in admitting as certain facts of this kind which are supported by a single doc.u.ment, and this is how we deal, in practice, with periods of which little is known. The inst.i.tutions of the Gauls and Germans are described from the unique texts of Caesar and Tacitus. Facts so easy to discover are forced upon the authors of descriptions much as realities are forced upon poets.
II. On the other hand, a statement in a doc.u.ment as to an objective fact is never enough to establish that fact. The chances of falsehood or error are so many, the conditions which gave rise to the statement are so little known, that we cannot be sure that none of these chances has taken effect. The critical examination provides no definitive solution; it is indispensable if we are to avoid error, but it is insufficient to conduct us to truth.
Criticism can _prove_ no fact; it only yields probabilities. Its end and result is to decompose doc.u.ments into statements, each labelled with an estimate of its value--worthless statement, statement open to suspicion (strong or weak), statement probably (or, very probably) true, statement of unknown value.
Of all these different kinds of results one only is definitive--_the statement of an author who can have had no information on the fact he states is null and void_; it is to be rejected as we reject an apocryphal doc.u.ment.[169] But criticism here merely destroys illusory sources of information; it supplies nothing certain to take their place.
The only sure results of criticism are _negative_. All the positive results are subject to doubt; they reduce to propositions of the form: "There are chances for or against the truth of such and such a statement." Chances only. A statement open to suspicion may turn out to be true; a statement whose truth is probable may, after all, be false.
Instances occur continually, and we are never sufficiently well acquainted with the conditions under which the observation was made to _know_ whether it was made ill or well.
In order to obtain a definitive result we require a final operation.
After pa.s.sing through the ordeal of criticism, statements present themselves as probable or improbable. But even the most probable of them, taken by themselves, remain mere probabilities: to pa.s.s from them to categorical propositions in scientific form is a step we have no right to take; a proposition in a science is an a.s.sertion not open to debate, and that is what the statements we have before us are not. It is a principle common to all sciences of observation not to base a scientific conclusion on a single observation; the fact must have been corroborated by several independent observations before it is affirmed categorically. History, with its imperfect modes of acquiring information, has less right than any other science to claim exemption from this principle. An historical statement is, in the most favourable case, but an indifferently made observation, and needs other observations to corroborate it.
It is by combining observations that every science is built up: a scientific fact is a centre on which several different observations converge.[170] Each observation is subject to chances of error which cannot be entirely eliminated; but if several observations agree, this can hardly be in virtue of a common error: the more probable explanation of the agreement is that the observers have all seen the same reality and have all described it correctly. Errors are personal and tend to diverge; it is the correct observations that agree.
Applied to history, this principle leads to a last series of operations, intermediate between purely a.n.a.lytical criticism and the synthetic operations--the comparison of statements.
We begin by cla.s.sifying the results yielded by critical a.n.a.lysis in such a way as to bring together those statements which relate to the same fact. The operation is facilitated mechanically by the method of slips.
Either each statement has been entered on a separate slip, or else a single slip has been a.s.signed for each fact, and the different statements relating to it entered upon the slip as met with in the course of reading. By bringing the statements together we learn the extent of our information on the fact; the definitive conclusion depends on the relation between the statements. We have, then, to study separately the different cases which may occur.
III. Most frequently, except in contemporary history, the doc.u.ments only supply a single statement on a given fact. In such a case all the other sciences follow an invariable rule: an isolated observation is not admitted into science; it is quoted (with the observer"s name), but no conclusions are drawn from it. Historians have no avowable motive for proceeding otherwise. When a fact is supported by no more than the statement of a single man, however honest he may be, historians ought not to a.s.sert it, but to do as men of science do--give the reference (Thucydides states, Caesar says that ...); this is all they have a right to affirm. In reality they all retain the habit of stating facts, as was done in the middle ages, on the _authority_ of Thucydides or of Caesar; many are simple enough to do so in express terms. Thus, allowing themselves to be guided by natural credulity, unchecked by science, historians end by admitting, on the insufficient presumption afforded by a unique doc.u.ment, any statement which does not happen to be contradicted by another doc.u.ment. Hence the absurd consequence that history is more positive, and seems better established in regard to those little known periods which are represented by a single writer than in regard to facts known from thousands of doc.u.ments which contradict each other. The wars of the Medes known to Herodotus alone, the adventures of Fredegonda related by none but Gregory of Tours, are less subject to discussion than the events of the French Revolution, which have been described by hundreds of contemporaries. This is a discreditable state of things which cannot be ended except by a revolution in the minds of historians.
IV. When we have several statements relating to the same fact, they may contradict each other or they may agree. In order to be certain that they really do contradict each other, we have to make sure that they do actually relate to the same fact. Two apparently contradictory statements may be merely parallel; they may not relate exactly to the same moment, the same place, the same persons, the same episodes of an event, and they may be both correct.[171] We must not, however, infer that they confirm each other; each comes under the category of unique statements.
If the contradiction is real, at least one of the statements is false.
In such cases it is a natural tendency to seek to reconcile them by a compromise--to split the difference. This peace-making spirit is the reverse of scientific. A says two and two make four; B says they make five. We are not to conclude that two and two make four and a half; we must examine and see which is right. This examination is the work of criticism. Of two contradictory statements, it nearly always happens that one is open to suspicion; this should be rejected if the competing statement has been judged very probably true. If both are open to suspicion, we abstain from drawing any conclusion. We do the same if several statements open to suspicion agree together as against a single statement which is not suspected.[172]
V. When several statements agree, it is still necessary to resist the natural tendency to believe that the fact has been demonstrated. The first impulse is to count each doc.u.ment as one source of information. We are well aware in matters of every-day life that men are apt to copy each other, that a single narrative often serves the turn of several narrators, that several newspapers sometimes happen to publish the same correspondence, that several reporters sometimes agree to let one of their number do the work for all. We have, in such a case, several doc.u.ments, several statements--have we the same number of observations?
Obviously not. When one statement reproduces another, it does not const.i.tute a new observation, and even if an observation were to be reproduced by a hundred different authors, these hundred copies would amount to no more than one observation. To count them as a hundred would be the same thing as to count a hundred printed copies of the same book as a hundred different doc.u.ments. But the respect paid to "historical doc.u.ments" is sometimes stronger than obvious truth. The same statement occurring in several different doc.u.ments by different authors has an illusory appearance of multiplicity; an identical fact related in ten different doc.u.ments at once gives the impression of being established by ten agreeing observations. This impression is to be distrusted. An agreement is only conclusive when the agreeing statements represent _observations_ which are independent of each other. Before we draw any conclusion from an agreement we must examine whether it is an agreement between _independent_ observations. Two operations are thus required.
(1) We begin by inquiring whether the statements are independent, or are reproductions of one and the same observation. This inquiry is partly the work of that part of external criticism which deals with the investigation of sources;[173] but that investigation only touches the relations between written doc.u.ments, and stops short when it has determined which pa.s.sages of an author are borrowed from other authors.
Borrowed pa.s.sages are to be rejected without discussion. But the same work remains to be done in reference to statements which were not committed to writing. We have to compare the statements which relate to the same fact, in order to find out whether they proceeded originally from different observers, or at least from different observations.
The principle is a.n.a.logous to that employed in the investigation of sources. The details of a social fact are so manifold, and there are so many different ways of looking at the same fact, that two independent observers cannot possibly give completely coincident accounts; if two statements present the same details in the same order, they must be derived from a common observation; different observations are bound to diverge somewhere. We may often apply an _a priori_ principle: if the fact was of such a nature that it could only be observed or reported by a single observer, then all the accounts of it must be derived from a single observation. These principles[174] enable us to recognise many cases of different observations, and still more numerous cases of observations being reproduced.
There remains a great number of doubtful cases. The natural tendency is to treat them as if they were cases of independent observation. But the scientific procedure would be the exact reverse of this: as long as the statements are not proved to be independent we have no right to a.s.sume that their agreement is conclusive.
It is only after we have determined the relations between the different statements that we can begin to count them and examine into their agreement. Here again we have to distrust the first impulse; the kind of agreement which is really conclusive is not, as one would naturally imagine, a perfect similarity between two narratives, but an occasional coincidence between two narratives which only partially resemble each other. The natural tendency is to think that the closer the agreement is, the greater is its demonstrative power; we ought, on the contrary, to adopt as a rule the paradox that an agreement proves more when it is confined to a small number of circ.u.mstances. It is at such points of coincidence between diverging statements that we are to look for scientifically established historical facts.
(2) Before drawing any conclusions it remains to make sure whether the _different_ observations of the same fact are entirely _independent_; for it is possible that one may have influenced another to such a degree that their agreement is inconclusive. We have to guard against the following cases:--
(_a_) The different observations have been made by the same author, who has recorded them either in the same or in different doc.u.ments; special reasons must then be had before it can be a.s.sumed that the author really made the observation afresh, and did not content himself with merely repeating a single observation.
(_b_) There were several observers, but they commissioned one of their number to write a single doc.u.ment. We have to ascertain whether the doc.u.ment merely gives the statements of the writer, or whether the other observers checked his work.
(_c_) Several observers recorded their observations in different doc.u.ments, but under similar conditions. We must apply the list of critical questions in order to ascertain whether they were not all subject to the same influences, predisposing to falsehood or error; whether, for example, they had a common interest, a common vanity, or common prejudices.
The only observations which are certainly independent are those which are contained in different doc.u.ments, written by different authors, who belonged to different groups, and worked under different conditions.
Cases of perfectly conclusive agreement are thus rare, except in reference to modern periods.
The possibility of proving an historical fact depends on the number of independent doc.u.ments relating to it which have been preserved, and the preservation of the doc.u.ments is a matter of chance; this explains the share which chance has in the formation of historical science.
The facts which it is possible to establish are chiefly those which cover a large extent of s.p.a.ce or time (sometimes called _general_ facts), customs, doctrines, inst.i.tutions, great events; they were easier to observe than the others, and are now easier to prove. Historical method is not, however, essentially powerless to establish facts of short duration and limited extent (those which are called _particular facts_), such as a saying, a momentary act. It is enough that several persons should have been present when the fact occurred, that they should have recorded it, and that their writings should have come down to us. We know what were the words which Luther uttered at the Diet of Worms; we know that he did not say what tradition puts in his mouth.
This concurrence of favourable conditions becomes more and more frequent with the organisation of newspapers, of shorthand writers, and of depositories of doc.u.ments.
In the case of antiquity and the middle ages historical knowledge is limited to general facts by the scarcity of doc.u.ments. In dealing with contemporary history it is possible to include more and more particular facts. The general public supposes the opposite of this; it is suspicious about contemporary facts, with reference to which it sees contradictory narratives circulating, and believes without hesitation ancient facts, which it does not see contradicted anywhere. Its confidence is at its greatest in respect of that history which we have not the means of knowing, and its scepticism increases with the means of knowledge.
VI. _Agreement between doc.u.ments_ leads to conclusions which are not all of them definitive. In order to complete and rectify our conclusions we have still to study _the harmony of the facts_.
Several facts which, taken in isolation, are only imperfectly proved, may confirm each other in such a manner as to produce a collective certainty. The facts which the doc.u.ments present in isolation have sometimes been in reality sufficiently near each other to be connected.
Of this kind are the successive actions of the same man or of the same group of men, the habits of the same group at different epochs separated by short intervals, or of similar groups at the same epoch. It is no doubt possible that one of several a.n.a.logous facts may be true and another false; the certainty of the first does not justify the categorical a.s.sertion of the second. But yet the harmony of several such facts, each proved imperfectly, yields a kind of certainty; the facts do not, in the strict sense of the word, prove, but they _confirm_[175]
each other. The doubt which attached to each one of them disappears; we obtain that species of certainty which is produced by the interconnection of facts. Thus the comparison of conclusions which are separately doubtful yields a whole which is morally certain. In an itinerary of a sovereign, the days and the places confirm each other when they harmonize so as to form a coherent whole. An inst.i.tution or a popular usage is established by the harmony of accounts, each of which is no more than probable, relating to different times and places.
This method is a difficult one to apply. The notion of harmony is a much vaguer one than that of agreement. We cannot a.s.sign any precise general rules for distinguishing facts which are sufficiently connected to form a whole, the harmony of whose parts would be conclusive; nor can we determine beforehand the duration and extent of that which may be taken to form a whole. Facts separated by half a century of time and a hundred leagues of s.p.a.ce may confirm each other in such a way as to establish a popular usage (for example, among the ancient Germans); but they would prove nothing if they were taken from a heterogeneous society subject to rapid evolution (take, for example, French society in 1750, and again in 1800, in Alsace and in Provence). Here we have to study the relation between the facts. This brings us to the beginnings of historical construction; here is the transition from a.n.a.lytical to synthetic operations.
VII. But it remains to consider cases of discordance between facts established by doc.u.ments and other facts established by other methods.
It happens sometimes that a fact obtained as an historical conclusion is in contradiction with a body of known historical facts, or with the sum of our knowledge of humanity founded on direct observation, or with a scientific law established by the regular method of an established science. In the first two cases the fact is only in conflict with history, psychology, or sociology, all imperfectly established sciences; we then simply call the fact _improbable_. If it is in conflict with a true science it becomes a _miracle_. What are we to do with an improbable or miraculous fact? Are we to admit it after examination of the doc.u.ments, or are we to pa.s.s on and shelve the question?
_Improbability_ is not a scientific notion; it varies with the individual. Each person finds improbable what he is not accustomed to see: a peasant would think the telephone much more improbable than a ghost; a king of Siam refused to believe in the existence of ice. It is important to know who precisely it is to whom the fact appears to be improbable. Is it to the ma.s.s who have no scientific culture? For these, science is more improbable than miracle, physiology than spiritualism; their notions of improbability are worthless. Is it to the man who possesses scientific culture? If so, we have to deal with that which seems improbable to a scientific mind, and it would be more accurate to say that the fact is contrary to the results of science--that there is disagreement between the direct observations of men of science and the indirect testimony of the doc.u.ments.
How is this conflict to be decided? The question has no great practical interest; nearly all the doc.u.ments which relate miraculous facts are already open to suspicion on other grounds, and would be discarded by a sound criticism. But the question of miracles has raised such pa.s.sions that it may be well to indicate how it affects the historian.[176]
The general tendency to believe in the marvellous has filled with miraculous facts the doc.u.ments of nearly every people. Historically the existence of the devil is much better proved than that of Pisistratus: there has not been preserved a single word of a contemporary of Pisistratus saying that he has seen him; thousands of "ocular witnesses"
declare they have seen the devil; few historical facts have been established by so great a number of independent testimonies. However, we do not hesitate to reject the devil and to accept Pisistratus. For the existence of the devil would be irreconcilable with the laws of all the established sciences.
For the historian the solution of the problem is obvious.[177] The observations whose results are contained in historical doc.u.ments are never of equal value with those of contemporary scientists; we have already shown why. The indirect method of history is always inferior to the direct methods of the sciences of observation. If its results do not harmonise with theirs, it is history which must give way; historical science, with its imperfect means of information, cannot claim to check, contradict, or correct the results of other sciences, but must rather use their results to correct its own. The progress of the direct sciences sometimes modifies the results of historical interpretation; a fact established by direct observation aids in the comprehension and criticism of doc.u.ments. Cases of stigmata and nervous anaesthesia which have been scientifically observed have led to the admission as true of historical narratives of a.n.a.logous facts, as in the case of the stigmata of certain saints and the possessed nuns of Loudun. But history cannot aid the progress of the direct sciences. It is kept at a distance from reality by its indirect means of information, and must accept the laws that are established by those sciences which come into immediate contact with reality. In order to reject one of these laws new direct observations are necessary. Such revolutions are possible, but they must be brought about from within. History has no power to take the initiative in them.
The solution is not so clear in the case of facts which do not harmonise with a body of historical knowledge or with the sciences, still in the embryonic stage, which deal with man. It depends on the opinion we form as to the value of such knowledge. We can at least lay down the practical rule that in order to contradict history, psychology, or sociology, we must have very strong doc.u.ments, and this is a case which hardly ever occurs.