Of two modes of migration the history of mankind informs us, and so far as I can yet discover, of two only. In countries where life was yet unadjusted, and policy unformed, it sometimes happened, that, by the dissensions of heads of families, by the ambition of daring adventurers, by some accidental pressure of distress, or by the mere discontent of idleness, one part of the community broke off from the rest, and numbers, greater or smaller, forsook their habitations, put themselves under the command of some favourite of fortune, and with, or without the consent of their countrymen or governours, went out to see what better regions they could occupy, and in what place, by conquest or by treaty, they could gain a habitation. Sons of enterprise, like these, who committed to their own swords their hopes and their lives, when they left their country, became another nation, with designs, and prospects, and interests, of their own. They looked back no more to their former home; they expected no help from those whom they had left behind; if they conquered, they conquered for themselves; if they were destroyed, they were not by any other power either lamented or revenged. Of this kind seem to have been all the migrations of the early world, whether historical or fabulous, and of this kind were the eruptions of those nations, which, from the north, invaded the Roman empire, and filled Europe with new sovereignties. But when, by the gradual admission of wiser laws and gentler manners, society became more compacted and better regulated, it was found, that the power of every people consisted in union, produced by one common interest, and operating in joint efforts and consistent counsels. From this time independence perceptibly wasted away. No part of the nation was permitted to act for itself. All now had the same enemies and the same friends; the government protected individuals, and individuals were required to refer their designs to the prosperity of the government. By this principle it is, that states are formed and consolidated. Every man is taught to consider his own happiness, as combined with the publick prosperity, and to think himself great and powerful, in proportion to the greatness and power of his governours. Had the western continent been discovered between the fourth and tenth century, when all the northen world was in motion; and had navigation been, at that time, sufficiently advanced to make so long a passage easily practicable, there is little reason for doubting, but the intumescence of nations would have found its vent, like all other expansive violence, where there was least resistance; and that Huns and Vandals, instead of fighting their way to the south of Europe, would have gone, by thousands and by myriads, under their several chiefs, to take possession of regions smiling with pleasure, and waving with fertility, from which the naked inhabitants were unable to repel them.