It is much more than a treatise on economic principles; it contains a history of the gradual economic progress of human society, and it suggests the expectation of an indefinite augmentation of wealth and well-being.

Smith was entirely at one with the French Economists on the value of opulence for the civilisation and happiness of mankind.

But it was indirectly perhaps that his work contributed most effectively to the doctrine of the Progress of collective mankind.

[Footnote: It has been observed by Mr.Leslie Stephen that the doctrine of the rights of man lies in the background of Adam Smith's speculations.] His teaching that the free commercial intercourse of all the peoples of the world, unfettered by government policies, was to the greatest advantage of each, presented an ideal of the economic "solidarity" of the race, which was one element in the ideal of Progress.

And this principle soon began to affect practice.
Pitt assimilated it when he was a young man, and it is one of the distinctions of his statesmanship that he endeavoured to apply the doctrines of his master so far as the prevailing prejudices would allow him.
3.
A few writers of less weight and fame than Hume or Smith expressly studied history in the light of Progress.