Here we have labour divided by its different applications, but not requiring different degrees of capacity.

We have the average labour of the average man still.

And here we have a fact which, unlike the fact of skill--a thing in its nature confined to the few only--affords a real explanation, up to a certain point, of how ordinary labour as a whole, without ceasing to be ordinary labour, may rise from a lower to a higher grade of efficiency.
But such simple divisions of labour as those which are here in question fail, for a reason which will be specified in another moment, to carry us far in the history of industrial progress.

They do but bring us to the starting-point of production as it exists to-day.

The efficiency of productive effort has made all its most astounding advances since the precise time at which the _Wealth of Nations_ was written; and these advances we shall find that it is quite impossible to explain merely by a further division of average and equal labour.