Smith next proceeds to indicate the limits of this division of labour. Of such limits he mentions two: (1) In the first place it must be limited by the extent of the market. “When the market is very small, no person can have any encouragement to dedicate himself entirely to one employment, for want of the power to exchange all that surplus part of the produce of his own labour, which is over and above his own consumption, for such parts of the produce of other men’s labour as he has occasion for.”[137] This is why foreign trade, including trade with the colonies, by extending the market for some products is favourable to further division of labour and a further increase of wealth. (2) The other consideration which, according to Smith, limits division of labour is the quantity of capital available.[138] The significance of this observation is not quite so obvious as that of the former one. Here it seems to us that a conclusion drawn from one particular trade has been applied to industry as a whole. It may be true of a private manufacturer that he will be able to push technical division of labour further than any of his rivals provided he has more capital than they; but taking society as a whole it is clear that the existence of division of labour enables the same product to be produced with less capital than is necessary for the single producer.[139] Such is an outline of Adam Smith’s theory of division of labour—a theory so familiar to everyone to-day that we are often unable to realise its importance and to appreciate its originality, and this despite the fact that certain sociologists like Durkheim have hailed it as supplying the basis of a new ethic. Juxtaposed with the Physiocratic theory, it is not very difficult to realise its superiority.