That these papers were not designed to appear in a collective form, or indeed to court the more public light at all, needs no disclosure. They are published out of regard to the wish of known and unknown friends by whom, when in a fugitive form, they were received with so curious an interest as to make one feel already that there are minds which such forms of truth may touch. In making the present selection, partly from manuscript, and partly from articles already published, I have been guided less by the wish to constitute the papers a connected series than to exhibit the application of the principle in various directions. They will be found, therefore, of unequal interest and value, according to the standpoint from which they are regarded. Thus some are designed with a directly practical and popular bearing, others being more expository, and slightly apologetic in tone. The risk of combining two objects so very different is somewhat serious. But, for the reason named, having taken this responsibility, the only compensation I can offer is to indicate which of the papers incline to the one side or to the other. "Degeneration," "Growth," "Mortification," "Conformity to Type," "Semi-Parasitism," and "Parasitism" belong to the more practical order; and while one or two are intermediate, "Biogenesis," "Death," and "Eternal Life" may be offered to those who find the atmosphere of the former uncongenial. It will not disguise itself, however, that, owing to the circumstances in which they were prepared, all the papers are more or less practical in their aim; so that to the merely philosophical reader there is little to be offered except--and that only with the greatest diffidence--the Introductory chapter. In the Introduction, which the general reader may do well to ignore, I have briefly stated the case for Natural Law in the Spiritual World. The extension of Analogy to Laws, or rather the extension of the Laws themselves so far as known to me, is new; and I cannot hope to have escaped the mistakes and misadventures of a first exploration in an unsurveyed land. So general has been the survey that I have not even paused to define specially to what departments of the Spiritual World exclusively the principle is to be applied. The danger of making a new principle apply too widely inculcates here the utmost caution. One thing is certain, and I state it pointedly, the application of Natural Law to the Spiritual World has decided and necessary limits. And if elsewhere with undue enthusiasm I seem to magnify the principle at stake, the exaggeration--like the extreme amplification of the moon's disc when near the horizon--must be charged to that almost necessary aberration of light which distorts every new idea while it is yet slowly climbing to its zenith.