"In the Decline and Fall, the civic humanist cycle of corruption, so often repeated in Gibbon's history, was balanced by another and newer theme, the Enlightenment's conception of the development of civilisation, which surrounds the work with an optimism which the story it tells, by itself, could hardly warrant. The notion of the gradual progress of the useful arts, through human industry, is one aspect of that optimism: Gibbon owes a debt, reflected in his footnotes, to Smith's Wealth of Nations. It is true that this version of progress is not heavily stressed; in the Decline and Fall, the most obvious antithesis is still the old one of republican patriotism and barbarian hardihood set against the "indolence", "luxury" and "effeminacy" of supine Asiatics and of once energetic former barbarian conquerors enervated by their own success. Yet there is clearly another possible antithesis to indolence and luxury: industry and a permissible (if still dangerous) civilised opulence."