salvation of the elect, or mental liberty, or the union of the soul with God. If, indeed, it is only thereby meant to use one or other of these as a central idea for convenience, in order to group others around it, no fault can be found with such a proceeding: and in this sense I should myself call the Incarnation the central aspect of Christianity, out of which the three main aspects of its teaching take their rise, the sacramental, the hierarchical, and the ascetic. But one aspect of Revelation must not be allowed to exclude or to obscure another; and Christianity is dogmatical, devotional, practical all at once; it is esoteric and exoteric; it is indulgent and strict; it is light and dark; it is love, and it is fear. 4. When an idea, whether real or not, is of a nature to arrest and possess the mind, it may be said to have life, that is, to live in the mind which is its recipient. Thus mathematical ideas, real as they are, can hardly properly be called living, at least ordinarily. But, when some great enunciation, whether true or false, about human nature, or present good, or government, or duty, or religion, is carried forward into the public throng of men and draws attention, then it is not merely received passively in this or that form into many minds, but it becomes an active principle within them, leading them to an ever-new contemplation of itself, to an application of it in various directions, and a propagation of it on every side. Such is the doctrine of the divine right of kings, or of the rights of man, or of the anti-social bearings of a priesthood, or utilitarianism, or free trade, or the duty of benevolent enterprises, or the philosophy of Zeno or Epicurus, doctrines which are of a nature to attract and influence, and have so far a _primâ facie_ reality, that they may be looked at on many sides and strike various minds very variously. Let one such idea get possession of the popular mind, or the mind of any portion of the community, and it is not difficult to understand what will be the result. At first men will not fully realize what it is that moves them, and will express and explain themselves inadequately. There will be a general agitation of thought, and an action of mind upon mind. There will be a time of confusion, when conceptions and misconceptions are in conflict, and it is uncertain whether anything is to come of the idea at all, or which view of it is to get the start of the others. New lights will be brought to bear upon the original statements of the doctrine put forward; judgments and aspects will accumulate. After a while some definite teaching emerges; and, as time proceeds, one view will be modified or expanded by another, and then combined with a third; till the idea to which these various aspects belong, will be to each mind separately what at first it was only to all together. It will be surveyed too in its relation to other doctrines or facts, to other natural laws or established customs, to the