Principles, p

14. W. ofN., vol. I, pp. 49-50: In the advanced state of society, allowances of this kind, for superior hardship and superior skill, are commonly made in the wages of labour; and something of the same kind must probably hâve taken place in its earliest and rudest period. In this State of things, the whole produce of labour balongs to the labourer; and the quantUy of labour commonly employed in acquiring or producing any commodity is the only circumstance whioh can reguiate the quantity of labour which it ought commonly to purchase, command, or exchange for.