In 1804 copyright both in Theory of Moral Sentiments and Wealth of Nations expired. Although the former had sold well during the 1790s, its central theses had been criticised by Thomas Reid and also by his student, Dugald Stewart; and Smith's ‘sympathetic’ account of human conduct became increasingly peripheral to the development of moral philosophy during the first third of the nineteenth century. Theory of Moral Sentiments did remain in print, editions appearing regularly every decade (apart from the 1830s) until the end of the century. But as James Bonar observed, although Smith's first book made his reputation and provided the opportunities for travel and reflection that enabled him to write the second, it ‘has needed all the fame of the second to keep alive the memory of the first.’ Scholarly discussion of Theory of Moral Sentiments has indeed been at best patchy until very recently – only the sustained revival since the 1970s of interest in the Scottish Enlightenment has brought the work back into prominence, three separate editions of the book being currently available in Britain. Essays on Philosophical Subjects never found a strong following, and so until Cannan published his edition of the Lectures on Justice, Police, Revenue, and Arms in 1896, ‘the writings of Adam Smith’ were equivalent to these three books only, only one of which, the Wealth of Nations, enjoyed wide circulation and recognition. And this circumstance persisted well into the twentieth century, for although the importance of the Lectures was immediately acknowledged, the book sold poorly until the 1920s, a period in which there was a general, international revival of interest in the work of Smith, cut short in mid-century by the Second World War.

Throughout the nineteenth century, therefore, the reputation of Adam Smith was associated almost exclusively with his Wealth of Nations. While the work remained in copyright the text was published as it stood, with the addition of advertisements to the third and fourth editions, and an index.