It is a minor defect in Todd’s _St. Patrick_ that he is not impartial. By this I mean that he wrote with an unmistakable ecclesiastical bias. It is not implied that he would have ever stooped to a misrepresentation of the evidence for the purpose of proving a particular thesis. No reader would accuse him of that. But it is clear that he was anxious to establish a particular thesis. He does not conceal that the conclusions to which the evidence, as he interpreted it, conducted him were conclusions which he wished to reach. In other words, he approached a historical problem, with a distinct preference for one solution rather than another; and this preference was due to an interest totally irrelevant to mere historical truth. The business of a historian is to ascertain facts. There is something essentially absurd in his wishing that any alleged fact should turn out to be true or should turn out to be false. So far as he entertains a wish of the kind, his attitude is not critical. The justification of the present biography is that it rests upon a methodical examination of the sources, and that the conclusions, whether right or wrong, were reached without any prepossession. For one whose interest in the subject is purely intellectual, it was a matter of unmixed indifference what answer might be found to any one of the vexed questions. I will not anticipate my conclusions here, but I may say that they tend to show that the Roman Catholic conception of St. Patrick’s work is, generally, nearer to historical fact than the views of some anti-Papal divines. The fragmentary material, presenting endless difficulties and problems, might have been treated with much less trouble to myself if I had been content to weave, as Todd has done, technical discussions into the story. It was less easy to do what I have attempted, to cast matter of this kind into the literary shape of a biography—a choice which necessitated long appendices supplying the justifications and groundwork. These appendices represent the work which belongs to the science of history; the text is an effort in the art of historiography.[1] It should be needless to say that, in dealing with such fragmentary material, reconstructions and hypotheses are inevitable. In ancient and mediaeval history, as in physical science, hypotheses, founded on a critical examination of the data, are necessary for the advancement of knowledge. The reconstructions may fall to-morrow, but, if they are legitimate, they will not have been useless.