The Trades-Unions and Brotherhoods of the present day cannot plead the provocations and justifications of their mediæval predecessors. It cannot be denied, however, that they have some provocations and justifications in the bad example set before them by the various combinations (implied or explicit) of the Wages-payers as a class. If the Wages-payers combine, then the Wages-takers would seem to have no resource but in combination. Both alike are wrong in this. Both alike oppose in this the spirit of Political Economy, which is ever the spirit of Freedom, and is ever against such factitious associations for such purposes, because they tend to destroy the independence of personal action on the part of both payers and takers of wages, and tend also to bring all the workmen of any one general grade down to one level of effort and reward. (i) Lastly, we must note the influence of _Casual Events_ upon wages, as these events affect the Supply of laborers. For example, in 1348, a terrible plague, called the Black Death, invaded England and swept away more than one-half of its population. "Even when the first burst of panic was over, the sudden rise of wages consequent on the enormous diminution in the supply of free labor, though accompanied by a corresponding rise in the price of food, rudely disturbed the course of industrial employments; harvests rotted on the ground, and fields were left untilled, not merely from scarcity of hands, but from the strife which now for the first time revealed itself between Capital and Labor" (Green). The landowners of the country districts, and the craftsmen of the towns, not understanding the law of Wages as an invariable resultant of the Demand and Supply of laborers, were scandalized by what seemed to them the extravagant demands of the new labor-class. Parliament equally ignorant with the People of the natural economic law, enacted as follows: "_Every man or woman of whatsoever condition, free or bond, able in body, and within the age of threescore years, and not having of his own whereof he may live, nor land of his own about the tillage of which he may occupy himself, and not serving any other, shall be bound to serve the employer who shall require him to do so, and shall take only the wages which were accustomed to be taken in the neighborhood where he is bound to serve two years before the plague began._" Afterwards, the runaway laborer was ordered by Parliamentary enactment to be branded in the forehead by a hot iron, and the harboring of the country serfs in the towns, in which under their civic rules a serf keeping himself a year and a day was thereafter free, was rigorously forbidden. These acts of Parliament, and many more of the same kind, were powerless to keep down wages to the old standard, but were powerful to keep up ill-blood and social discontent. They prepared the way for agitators like John Ball, for the poet-agitator Piers Ploughman, and for the great Peasant Revolt of 1381.