Nigel Biggar retired a few months ago from the Regius Professorship of Moral and Pastoral Theology at Oxford. He is a notable figure in the world of moral philosophy, not only because of his distinguished academic career as an ethicist but also because of his persistent refusal to observe the conventional pieties which characterise so much that is written in his field.

There are few notions more pious or conventional than that empires are wicked and that the British Empire was unutterably and irredeemably so. In 2017, Biggar initiated the ‘Ethics and Empire’ project at Oxford, which sought to explore the factual and moral basis for this hostility. The project, its author and the university were at once denounced by other scholars in the field on the grounds that the very idea of balance in this area is unacceptable. To quote one of the most vocal antagonists, ‘any attempt to create a balance sheet of the good and evil of empire can’t be based on rigorous scholarship.’

This seems a surprising proposition. It is hard to think of any human institution enduring for centuries of which it can seriously be said it was all good or all bad. If the British Empire was all bad, then it stands almost unique in the three millennia of recorded human barbarism. Yet for three centuries, honourable men and women served the British Empire with pride and were admired for it by their contemporaries, including many of its subjects and some of its more articulate opponents. Something so paradoxical is surely worthy of serious examination. This is why Colonialism is an important book as well as a courageous one.

Biggar’s starting point is that empire is not a historical aberration or a departure from historical norms. It is part of the natural order of a world that until recently lacked stable frontiers formalised by an overarching scheme of international law. The armed migration of peoples in search of resources might serve to unlock the riches of the world and spread knowledge and technical competence, processes which potentially benefit all mankind.

Tout comprendre c’est tout pardonner is an aphorism variously attributed to Spinoza, Madame de Staël and Tolstoy. But Biggar’s quest for understanding has not made him an uncritical admirer of Britain’s empire or any other one. He acknowledges that colonialism severely disrupted existing patterns of indigenous life. It was often achieved or maintained through violence and injustice. In the last analysis, all states maintain themselves by force or the threat of it. Government, imperial or domestic, has always involved light and shade, achievement and failure, good and evil. Biggar’s point is that it falsifies history to collect together everything bad about an institution and serve it up as if it were the whole.

Biggar makes three broad points by way of mitigation when it comes to the British Empire’s legacy. First, many of the worst things were not the result of ideology or calculated policy. They were abuses which were recognised as such and addressed, not always successfully. Second, the disruption brought benefits as well as suffering. Practices such as slavery, cannibalism, sati and human sacrifice, which were by any standards barbarous, were eliminated. The ground was laid for an economic and social transformation that lifted much of the world out of extremes of poverty. Third, the British brought not just disruption but also the rule of law, constitutional government, honest administration, economic development and modern educational and research facilities, all long before they would have been achieved without European intervention.

Biggar takes his agenda from the Empire’s critics. He deals in turn with each of the principal criticisms, starting with slavery and going on to address racism, cultural aggression, population displacement, economic exploitation, authoritarianism and political violence. He confronts the famous horror stories: the Opium Wars, the Benin expedition, the Amritsar massacre, the suppression of the Mau Mau in Kenya. In each case, he sets out the historical context, which is so often absent. He acknowledges the respects in which the charges are justified, but points out in what respects they are unjustified or exaggerated. There are a few places where Biggar may be accused of tendentious selection or special pleading. But in general, his approach is objective and he fairly addresses the contrary arguments.

A good example is the chapter on slavery, which touches on perhaps the most sensitive and controversial issue of all. Biggar does not for a moment seek to defend the Atlantic slave trade, and recognises that it was imperialism that made it possible. It created the markets for slaves, the fleets which transported them and the legal and administrative framework that kept them in subjection. But if imperialism made slavery possible, it also enabled its suppression when sentiment changed. For a society such as Britain’s, imbued with Christian moral teaching, the trade was defensible only on the footing that black people were not really human. It was the rejection of that notion which transformed English attitudes to slavery in the course of the 18th century. Domestic slavery was banned in common law in the 1770s. After a long campaign by evangelical Christians, the slave trade was criminalised by statute in 1807 and slavery itself abolished throughout the British Empire in 1834. The Foreign Office and the Royal Navy campaigned for its international suppression throughout the 19th century. Britain was decades ahead of the rest of Europe and the United States in recognising the moral case against slavery and taking active steps to suppress it. The size, reach and diplomatic and naval power of the British Empire were by far the most significant factors in the demise in less than a century of an institution that had subsisted across the world throughout history.

Unless we draw up a balance sheet of empire, we will never understand one of the most significant forces in the making of the modern world. Inevitably, it will be an incomplete balance sheet. There will be credits and debits, but no bottom line. This is because, as Biggar points out, the good and bad things about empire are incommensurate. Depending on one’s values, one can read Colonialism and conclude that the British Empire was on balance a very good thing or a very bad thing. But one cannot read it and plausibly suggest that there is nothing to balance at all.

Would India be better off if it had not inherited its subcontinental identity, its framework of constitutional government, its economic infrastructure and the rule of law from Britain? Would sub-Saharan Africa be better off if Europeans had left it to itself? Would the world be better off if Europeans had never settled in North America? These questions are surely worth asking.

The real objection to empires has always been that they denied self-determination to indigenous populations. Self-determination is a moral good, but it is not the only one. Our forebears thought that sound government was better than self-government and that trade and economic and technical development were better for humanity than cultural autarky. This is not the modern consensus. But it is a morally defensible position.