The doctrine that the social value or market price of labour is also the ethical value or just price, is sometimes called the classical theory, inasmuch as it was held, at least implicitly, by the majority of the early economists of both France and England.[217] Under competitive conditions, said the Physiocrats, the price of labour as of all other things corresponds to the cost of production; that is, to the cost of subsistence for the labourer and his family. This is the natural law of wages, and being natural it is also just. Adam Smith likewise declared that competitive wages were natural wages, but he refrained from the explicit assertion that they were just wages. Nevertheless his abiding and oft-expressed faith in the theory that men's powers were substantially equal, and in the social beneficence of free competition, implied that conclusion. Although the great majority of his followers denied that economics had moral aspects, and sometimes asserted that there was no such thing as just or unjust wages, their teaching tended to convey the thought that competitively fixed wages were more or less in accordance with justice. As noted above, their belief in the efficacy of competition led them to the inference that a free contract is also a fair contract. By a free contract they meant for the most part one that is made in the open market, that is governed by the forces of supply and demand, and that, consequently, expresses the social economic value of the things exchanged. All the objections that have been brought against the rule of the prevailing rate apply even more strongly to the doctrine of the market rate. The former takes as a standard the scale of wages most frequently paid in the market, while the latter approves any scale that obtains in any group of labourers or section of the market. Both accept as the ultimate determinant of wage justice the preponderance of economic force. Neither gives any consideration to the moral claims of needs, efforts, or sacrifices. Unless we are to identify justice with power, might with right, we must regard these objections as irrefutable, and the market value doctrine as untenable. _The Mediæval Theory_