In the meantime, the Jews (and perhaps some other nations, but the Jews chiefly and principally) had been moving forward along a road wholly different. Breaking early away from the gods of nature, they advanced along the line of their moral consciousness; and leaving the nations to study physics, philosophy, and art, they confined themselves to man and to human life. Their theology grew up round the knowledge of good and evil, and God, with them, was the supreme Lord of the world, who stood towards man in the relation of a ruler and a judge. Holding such a faith, to them the toleration of paganism was an impossibility; the laws of nature might be many, but the law of conduct was one; there was one law and one king; and the conditions under which he governed the world, as embodied in the Decalogue or other similar code, were looked upon as iron and inflexible certainties, unalterable revelations of the will of an unalterable Being. So far there was little in common between this process and the other; but it was identical with it in this one important feature, that moral knowledge, like physical, admitted of degrees; and the successive steps of it were only purchasable by experience. The dispensation of the law, in the language of modern theology, was not the dispensation of grace, and the nature of good and evil disclosed itself slowly as men were able to comprehend it. Thus, no system of law or articles of belief were or could be complete and exhaustive for all time. Experience accumulates; new facts are observed, new forces display themselves, and all such formulae must necessarily be from period to period broken up and moulded afresh. And yet the steps already gained are a treasure so sacred, so liable are they at all times to be attacked by those lower and baser elements in our nature which it is their business to hold in check, that the better part of mankind have at all times practically regarded their creed as a sacred total to which nothing may be added, and from which nothing may be taken away; the suggestion of a new idea is resented as an encroachment, punished as an insidious piece of treason, and resisted by the combined forces of all common practical understandings, which know too well the value of what they have, to risk the venture upon untried change. Periods of religious transition, therefore, when the advance has been a real one, always have been violent, and probably will always continue to be so. They to whom the precious gift of fresh light has been given are called upon to exhibit their credentials as teachers in suffering for it. They, and those who oppose them, have alike a sacred cause; and the fearful spectacle arises of earnest, vehement men contending against each other as for their own souls, in fiery struggle. Persecutions come, and martyrdoms, and religions wars; and, at last, the old faith, like the phoenix, expires upon its altar, and the new rises out of the ashes.