The Honour Code: How Moral Revolutions Happen, By Kwame Anthony Appiah

In 1829 the Duke of Wellington, then Prime Minister, fought a well-advertised and much discussed duel with the Earl of Winchelsea half a mile south of Battersea Bridge. Less than three decades later it would be inconceivable that anyone, let alone the Prime Minister, would be allowed to engage in armed combat and possibly murder in the sure knowledge that there would be no legal or moral recriminations for doing so. Indeed, it would have been considered reprehensible.

This was a moral revolution: a profound shift in not just in ethical sentiment but in actual behaviour. Why, Kwame Anthony Appiah asks, do they happen? He argues rightly that these changes are not simply a matter of new or better moral arguments coming to light. In the case of duelling, the church had long considered it immoral. The philosophers of the Enlightenment considered it irrational. The state, all across Europe, had made it illegal and punishable. Appiah's answer, at least in part, is that moral revolutions happen when questions of honour are brought into play rather than ethics.

Honour, which he defines as entitlement to respect, and the honour codes and communities that sustain it, are remarkably powerful instruments for shaping human behaviour; the loss of honour – shame – even more so. Honour codes are not necessarily very moral – they may require one to commit immoral acts. In contemporary Pakistan the maintenance of family honour may require the murder of a daughter who has been raped. However, if honour and moral codes come into alinment, then change is coming.

Duelling in Britain was always a matter of honour, accorded and received by gentlemen alone. Membership of the ruling elite was rooted in an allegiance to an honour code that required, on occasion, individual armed combat as a method of dispute resolution. How could such a code also bring about the decline of duelling? On this, Appiah looks to Oscar Wilde, who argued that as long as war was wicked it would maintain its fascination but "when it is looked upon as vulgar it will cease to be popular".

At some point in the 1830s the balance of sentiment within the gentry came to see duelling as dishonourable, even laughable. First, because duelling was being practised by any number of the lower orders, its role in demarcating the closed world of the gentlemen was undermined. Second, because the power of this class to maintain itself beyond the law was successfully challenged if not broken by the great reform acts and the rest of the democratising forces of early Victorian England.

During the last quarter of the 19th century, American and European Christian missionaries in China were the leading forces in the moral campaign against foot binding. While their work ensured that the rest of the world became aware of the practice, it did little to shift attitudes in China. This came in the 1890s when the modernising wing of the imperial civil service could no longer sustain the notion that China was the centre of the universe in need of neither the respect nor ideas of the rest of the world. As a declining member of a wider community of nations it required both of these things and foot binding had come to be seen as an obstacle; a shameful and dishonourable practice. That sudden shift in perceptions led to the ruling elite abandoning it.

Honour and shame remain in our private and public vocabularies. As Appiah argues, they are powerful ways of turning private moral sentiments into public reform. Yet in the end it is the great subterranean shifts of international and class power the seem to truly drive the revolutions he describes. Shaping those revolutions is the task of politics. It is perhaps our curse that, were our ruling elites to use Appiah's honourable philosophical language, they would ring even more hollow than usual.

David Goldblatt's global history of football, 'The Ball Is Round', is published by Penguin