In almost every instance, it is an idle refinement to distinguish between the labour of those employed in agriculture, and of those employed in manufactures and commerce; for wealth is necessarily the result of both descriptions of labour, and consumption can no more take place independently of the one, than it can independently of the other. It is by their simultaneous concurrence that any thing becomes consumable, and, of course, that it comes to constitute wealth. How then are we entitled to compare their respective products, since it is impossible to distinguish these in the joint product, and thus appreciate the separate value of each? The value of growing wheat results as much from the industry of the reaper who gathers it in, of the thrasher who separates it from the chaff and straw, of the miller and baker who convert it successively into flour and bread, as it does from that of the ploughman and of the sower. Without the labour of the weaver, the raw material of flax would lose all its value, and be regarded as no way superior to the most useless weed that grows. What then can we gain by any attempts to determine which of these two species of labour conduces most to the advancement of national wealth; or, are they not as idle, as if we busied ourselves in inquiring, whether the right or the left foot is the most useful in walking? It is true, indeed, that in every species of manufacture, the workman adds to the value of the raw material a value exactly equal to that which was expended during the process of manufacture; and what is the conclusion we are to draw this? It is merely, that a certain exchange has taken place and that the food consumed by the manufacturer is now represented by the increase of value resulting from his manual labour. Thus wool, when converted into cloth, has gained a value precisely equal to that expended by the manufacturer during the conversion. But, if it is shown that, without this exchange, the wool would have remained without value, while, on the other hand, the food of the manufacturer would have been without a consumer; it will then appear, that this exchange has, in fact, done what is equivalent to creating these two values, and that it has proved to the society an operation infinitely more useful, than if an equal quantity of labour had been spent in the increase of that rude produce, which already existed in overabundance. The first description of labour has been truly productive; while the last would have been altogether unproductive, since it would not have created any value.