The clergy of the Established Church to a great extent form a caste, but without hereditary succession. This caste character of the clergy is a result of their segregation from secular employments, and of their corporate perpetuity. Serfdom had, in mediæval Europe, a similar effect, which was, at the same period, felt at the other extremity also of society, through the institution of feudal nobility. But the most widely-spread form of the institution was that which now appears to us the most hideous of all human institutions, that of slavery. Still we cannot pronounce it unnatural, for we find it, at certain stages of their development, among all races of men; and even constituting a regular part of the economy of certain insects. In Europe it is difficult to believe that some of the early advances of society could have been made without its aid. It belongs to that stage when wealth, which gives the leisure which makes any degree of intellectual culture possible, can only be secured by binding down the many to compulsory toil for the few, and giving to them all that the many can produce in excess of the absolute necessaries of existence. The Homeric chieftain was the product of this arrangement. So were the highly-cultured Greeks of the age of Pericles. It was the same with the governing class in the period of Roman greatness. It is, in one view, a very complete form of the institution, because it embraces every member of the community, from the top to the bottom. It divides society into two castes, assigning to one leisure, culture, the use of arms, government; to the other, denying them all participation in these advantages and employments, it assigns absolute subjection, labour, and bare subsistence. The history of this institution is very instructive. It shows how, in human affairs, circumstances rule and decide the question of expediency; and even that it is impossible to predicate of matters of this kind good or evil absolutely. Here, at all events, is something (it is, in fact, the very mould in which a community is cast,) which at one time builds up society, and at another overthrows it; which at one time is the cause and instrument of progress, and at other times retards, or reverses it; which, under some conditions, is not unfavourable to morality, and is under others immoral and demoralizing. Of all these arrangements, then, we may suppose that they were, in their respective times, necessary and useful. They appear to belong to early and transitional stages of society, and not, if there be, or ever is to be, such a state, to its maturity. They mean either that every member of society is not yet fit to be trusted; or that society cannot yet afford to endow all its members with freedom and power, and that, under such circumstances, more or less rigid restriction is an indispensable condition of life and growth.