We have now received a preliminary idea, although not from the study of a true parasite, of the essential principles involved in parasitism. And we may proceed to point out the correlative in the moral and spiritual spheres. We confine ourselves for the present to one point. The difference between the Hermit-crab and a true parasite is, that the former has acquired a semi-parasitic habit only with reference to _safety_. It may be that the Hermit devours as a preliminary the accommodating mollusc whose tenement it covets; but it would become a real parasite only on the supposition that the whelk was of such size as to keep providing for it throughout life, and that the external and internal organs of the crab should disappear, while it lived henceforth, by simple imbibition, upon the elaborated juices of its host. All the mollusc provides, however, for the crustacean in this instance is safety, and, accordingly in the meantime we limit our application to this. The true parasite presents us with an organism so much more degraded in all its parts, that its lessons may well be reserved until we have paved the way to understand the deeper bearings of the subject. The spiritual principle to be illustrated in the meantime stands thus: _Any principle which secures the safety of the individual without personal effort or the vital exercise of faculty is disastrous to moral character._ We do not begin by attempting to define words. Were we to define truly what is meant by safety or salvation, we should be spared further elaboration, and the law would stand out as a sententious common-place. But we have to deal with the ideas of safety as these are popularly held, and the chief purpose at this stage is to expose what may be called the Parasitic Doctrine of Salvation. The phases of religious experience about to be described may be unknown to many. It remains for those who are familiar with the religious conceptions of the masses to determine whether or not we are wasting words. What is meant by the Parasitic Doctrine of Salvation one may, perhaps, best explain by sketching two of its leading types. The first is the doctrine of the Church of Rome; the second, that represented by the narrower Evangelical Religion. We take these religions, however, not in their ideal form, with which possibly we should have little quarrel, but in their practical working, or in the form in which they are held especially by the rank and file of those who belong respectively to these communions. For the strength or weakness of any religious system is best judged from the form in which it presents itself to, and influences the common mind.