THE EVIDENCE
When we have to deal with a gap in history (and though none in Western European history is so strangely empty as this, yet there are very many minor ones which enable us to reason from their analogy), two methods of bridging the gap are present to the historian. The first is research into such rare contemporary records as may illustrate the period: the second is the parallel of what has happened elsewhere in the same case, or better still (when that is possible) the example of what was proceeding in similar places and under similar circumstances at the same time. And there is a third thing: both of these methods must be submitted to the criterion of common sense more thoroughly and more absolutely than the evidence of fuller periods. For when you have full evidence, even of a thing extraordinary, you must admit its truth. But when there is little evidence guess-work comes in, and common sense is the correction of guess-work.
If, for instance, I learn, as I can learn from contemporary records and from the witness of men still living, that at the battle of Gettysburg infantry advanced so boldly as to bayonet gunners at their guns, I must believe it although the event is astonishing.
If I learn, as I can learn, that a highly civilized and informed government like that of the French in 1870, entering into a war against a great rival, had only the old muzzle-loading cannon when their enemies were already equipped with modern breech-loading pieces, I must accept it on overwhelming evidence, in spite of my astonishment.
When even the miraculous appears in a record—if its human evidence is multiple, converging and exact—I must accept it or deny the value of human evidence.
But when I am dealing with a period or an event for which evidence is lacking or deficient, then obviously it is a sound criterion of criticism to accept the probable and not to presuppose the improbable. Common sense and general experience are nowhere more necessary than in their application, whether in a court of law or in the study of history, to those problems whose difficulty consists in the absence of direct proof. [Footnote: For instance, there is no contemporary account mentioning London during the last half of the fifth and nearly all the sixth century. Green, Freeman, Stubbs, say (making it up as they go along) that London ceased to exist: disappeared! Then (they assert) after a long period of complete abandonment it was laboriously cleared by a totally new race of men and as laboriously rebuilt on exactly the same site. The thing is not physically impossible, but it is so exceedingly improbable that common sense laughs at it.]
Remembering all this, let us first set down what is positively known from record with regard to the fate of Britain in the hundred and fifty years of “the gap.”
We begin by noting that there were many groups of German soldiery in Britain before the Pirate raids and that the southwest was—whether on account of earlier pirate raids or on account of Saxon settlers the descendants of Roman soldiers—called “the Saxon shore” long before the Imperial system broke down.
Next we turn to documents.
There is exactly one contemporary document professing to tell us anything at all of what happened within this considerable period, exactly one document set down by a witness; and that document is almost valueless for our purpose.