A few years ago, Jonathan A C Brown was the subject of one of those Twitter storms that have become such a familiar feature of the modern media age. A lecture he gave on the topic of this book, suggesting that Islamic forms of slavery were considerably more benign than Western ones, went viral, helped on its way by several right-wing news outlets. To some, it provided evidence of the kind of cultural relativism that is supposed to pervade the modern academy. At a time when ISIS was committing atrocities against the Yazidis of Iraq, here, it was said, was a professor of Islamic studies at Georgetown University ‘defending slavery’.

Slavery & Islam is Brown’s answer to his critics. It is, he says, a book for people who want to understand ‘how Muslims conceptualized, practiced and eventually abolished slavery’ through history and an exploration of the dilemmas faced by Muslims today, navigating between a religious tradition that is bound up in a veneration of the past and present-day understandings of profound moral failings in that very same past.

Brown shows why it is not simply a piece of Orientalism to speak of ‘Islamic slavery’, though the phrase has frequently been used by Orientalists. The term covers a very profound variety of experiences. At first glance, it may even seem crude to suggest that there is any commonality of experience between, say, the Turkish slave soldiers of the Abbasid caliphs or the powerful eunuchs of the Ottoman sultans and the individuals transported in chains across the Sahara to be sold in Cairo’s slave markets. We can, however, legitimately speak of it because the Islamic tradition itself identities a specific category of slavery, known by the Arabic term riqq. It is embedded in the Koran, the Hadith and the writings of the main Islamic legal authorities, and shaped how people who identified as Muslim thought of and practised slavery, whether they were in Tangier, Delhi or Belgrade.

It also seems plausible to argue that the framework provided by this tradition encouraged a less dreadful system of slavery than the one with which we associate that term in the West. Brown notes that, while there is nothing in the Islamic scriptures and the interpretations of them stating that slavery qua slavery is morally wrong, both the Koran and the Hadith are nonetheless replete with exhortations to the generous treatment of slaves and condemnations of those who mistreat them. A well-known hadith records Muhammad reproaching one of his companions for cursing a slave, reminding him, ‘Your slaves are your brothers, whom God has put under your control’, and detailing the range of responsibilities he owed his slaves. Obligations upon slave owners and ‘rights’ enjoyed by slaves were later codified in the vast corpus of sharia law; Brown shows how we can find them being enforced, as often as not in slaves’ favour, by Islamic judges from the 9th to the 19th centuries.

Slavery & Islam also brings out what its author calls an ‘impulse toward emancipation’ embedded in the scriptures. The freeing of slaves is repeatedly identified as a ready means of extirpating sin (a grand kind of ‘Hail Mary’), though in times past this had the unfortunate side effect of ensuring that the demand for new slaves stayed high and the barbaric trans-Sahara slave trade was maintained. Nevertheless, by the standards of its time, the treatment of slaves under sharia law was advanced: more than a thousand years after it had taken shape, it could still bear favourable comparison with the system of plantation slavery in the American South.

If the book had confined itself to these subjects, it would have done a valuable service. But this modest scholarly core serves as the launch pad for an extravagant and wearisome expedition into contemporary social criticism, the philosophy of knowledge and Foucauldian discourse analysis. The main purpose is to suggest that, since we in ‘the West’ do not agree on what slavery really is, we cannot be confident that we have in fact abolished it, rather than simply defined it in such a way as to suit the needs of the present capitalist order. As such, we should refrain from ever projecting Western conceptions of slavery onto foreign spaces and, especially, using them as the ‘building blocks of … discourses’ designed to ‘boost our own moral standing’.

The chapters in which this argument is developed provide an exercise in the continuum fallacy, supported by an eclecticism of evidence that is, frankly, extraordinary. In a parody of the Socratic method, Brown sets about trying to knock down the efforts of the great thinkers in the Western philosophical tradition to define slavery. Against Aristotle, Plato and the Emperor Hadrian, he sets quotations from Fight Club and The Matrix, an episode of Sherlock and a report he saw on CNN. Against Burke and Sir William Blackstone, he invokes a comment some guy made on his Facebook page. He dismisses the most broadly accepted definition of slavery as the legal status of owning a human being as property, common to both Western practice and the sharia, by offering quite ludicrously trivial remarks on how divorce proceedings in US courts reveal that people in the West ‘own’ each other, sort of. By way of proof, he offers a reference to a comment made by Russell Crowe, playing a corrupt New York City mayor, in the 2013 blockbuster film Broken City: ‘I own you.’

Brown tells us that his objective is to shatter the pretensions and lay bare the neuroses of the ‘global West’. But whatever one is to make of all this, it has little to do with the subject on which the author is really qualified to write – about which his readers may justifiably have expected to read. In one chapter of almost sixty pages, Islam appears on just five of them.

Slavery & Islam hints at some of the great questions that are still outstanding in this field: for example, how far a philosophical system that, at least in theory, sanctions enslavement on the basis of faith can accept universalist conceptions, such as the equality of man, that have become central to Western secular rights traditions. This is, to be sure, fraught intellectual terrain, but others have managed to tread it, including Henri Lauzière in his writings on Salafism, and Noah Salomon and Wael Hallaq in their writings on Islamic statehood. Jonathan Brown was attacked by pundits; this was his chance to provide a scholar’s reply. Instead, he has given us three hundred pages of amateur epistemology and callow whataboutery. Will a real Islamic scholar please stand up?