And as it is with individuals, so is it also with whole periods and cycles. For centuries together the believing spirit held undisputed sovereignty; and these were what are called 'ages of faith;' ages, that is, in which the highest business of the intellect was to pray rather than to investigate; when for every unusual phenomenon a supernatural cause was instinctively assumed; when wonders were credible in proportion to their magnitude; and theologians, with easy command of belief, added miracle to miracle and piled dogma upon dogma. Then the tide changed; a fresh era opened, which in the eyes of those who considered the old system the only right one, was the letting loose of the impersonated spirit of evil; when profane eyes were looking their idols in the face; when men were saying to the miraculous images, 'You are but stone and wood,' and to the piece of bread, 'You are but dust as I am dust;' and then the huge mediaeval fabric crumbled down in ruin. All forms of thought, all objects of devotion, are made thus liable to perpetual revision, if only that belief shall not petrify into habit, but remain the reasonable conviction of a reasonable soul. The change of times and the change of conditions change also the appearance of things which in themselves are the same which they always were. Facts supposed once to be as fixed as the stars melt into fiction. A closer acquaintance with the phenomena of experience has revealed to us the action of forces before undreamt of working throughout nature with unerring uniformity; and to the mediaeval stories of magic, witchcraft, or the miracles of saints, we are thus placed in a new relation. The direct evidence on which such stories were received may remain unimpaired, but it no longer produces the same conviction. Even in ordinary human things where the evidence is lost--as in some of our own State trials, and where we know only that it was such as brought conviction to judges, juries, and parliaments--historians do not hesitate to call their verdicts into question, thinking it more likely that whole masses of men should have been led away by passion or fraud or cowardice than that this or that particular crime should have been committed. That we often go beyond our office and exaggerate the value of our new criteria of truth may be possible enough; but it is no less certain that this is the tendency of modern thought. Our own age, like every age which has gone before it, judges the value of testimony, not by itself merely, but by the degree to which it corresponds with our own sense of the laws of probability; and we consider events probable or improbable by the habit of mind which is the result of our general knowledge and culture. To the Catholic of the middle ages a miracle was more likely than not; and when he was told that a miracle had been worked, he believed it as he would have believed had he been told that a shower of rain had fallen, or that the night frost had killed the buds