Another element of the solemn fitness of the type is found in the persistently _hereditary_ nature of leprosy. It may indeed sometimes arise of itself, even as did sin in the case of certain of the holy angels, and with our first parents; but when once it is introduced, in the case of any person, the terrible infection descends with unfailing certainty to all his descendants; and while, by suitable hygiene, it is possible to alleviate its violence, and retard its development, it is not possible to escape the terrible inheritance. Is anything more uniformly characteristic of sin? We may raise no end of metaphysical difficulties about the matter, and put unanswerable questions about freedom and responsibility; but there is no denying the hard fact that since sin first entered the race, in our first parents, not a child of man, of human father begotten, has escaped the taint. If various external influences, as in the case of leprosy, may, in some instances, modify its manifestations, yet no individual, in any class or condition of mankind, escapes the taint. The most cultivated and the most barbarous alike, come into the world so constituted that, quite antecedent to any act of free choice on their part, we know that it is not more certain that they will eat than that, when they begin to exercise freedom, they will, each and every one, use their moral freedom wrongly,--in a word, will sin. No doubt, then, when such prominence is given to leprosy among diseases, in the Mosaic symbolism and elsewhere, it is with intent, among other truths, to keep before the mind this very solemn and awful fact with regard to the sin which it so fitly symbolises.