There are times indeed when the mere instructiveness of a history, independently of practical use, is a sufficient justification for writing it;—times when it is important to take the gauge of past knowledge as the condition of a step forward in the future. Those who are accustomed to meditate on the present age, on the multifarious elements which in a time of great peace are quietly laying the basis of great changes, and on the unity of intellectual condition which the international intercourse is creating in the world of letters, as really as in that of industry, will perhaps think that the present is such a period, when the knowledge of the history of the former perils of the Christian faith, the nature of the attack and of the defence, is itself of value in regard to the prospects of the future.(1008) Those again also, who are accustomed to look at the contemporary works of evidence in our own country, will deplore the fact that in many cases, however well meant in spirit, they are essentially deficient in a due appreciation of the precise origin and character of present forms of doubt, and the natural and literary history of doubt in general;(1009) reproducing arguments unanswerable against older kinds of doubt, but unavailing against the modern, like wooden walls against modern weapons of war. We stand in the presence of forms of doubt, which press us more nearly than those of former times, because they do not supersede Christianity by disbelief, but disintegrate it by eclecticism; which come in the guise of erudition, unknown in former times, appealing to new canons of truth, reposing on new methods, invested with a new air. In such a moment a reconsideration of the struggles of past ages becomes indirectly a contribution to the evidences, by supplying the knowledge of similarity and contrast, which is necessary, as a preliminary, before entering on a new conflict. The dangers to faith in the present day are sometimes exaggerated; but there cannot be a doubt that we live in a time when old creeds are in peril; when the doubt is the result not of ignorance, but of knowledge, and acts in the minds that are pre-eminent for intellectual influence, and advances with a firmness that is not to be repelled by force but by argument. It is not the duty of Christians to shut their eyes to the danger, like the ostrich, which supposes by burying her eyes in the sand to avoid the huntsman’s arrow. There seems accordingly special reason why in such an age an acquaintance with the forms of doubt is requisite on the part of those who have to minister the religion which is the subject of attack.