Editors’ Note: Matthew Wyman-McCarthy examines the role of British abolitionism as a case study and model for the longtermism movement in William MacAskill’s What We Owe the Future (Basic Books, 2022).
Throughout the eighteenth century, most Britons who bothered to reflect on the transatlantic slave trade at all would have considered it an unalterable fact of how the world worked. This began to change in the late 1780s when a small group of London-based activists came together to begin advocating for the abolition of the traffic of captive Africans to the Americas. At the time, no one could have predicted how rapidly this movement would spread. Within a few short years, Britain was awash in pamphlets, poems, sermons, and images detailing the horrors of the slave trade and life on plantations in Britain’s West Indian colonies. Petitions flooded parliament from local antislavery chapters throughout the country. A movement to boycott slave-grown sugar—the most profitable of plantation commodities—brought together citizens from across social and religious divides. Though antislavery momentum in Britain would be temporarily halted by a conservative backlash to the French Revolution, it remerged in the early nineteenth century thanks to the persistence of activists at home and resistance by enslaved people across the Atlantic, leading to the abolition of the slave trade in 1807 and the abolition of slavery itself in 1833. For decades afterwards, the British Navy actively suppressed slave trading among other nations as well. Until well into the twentieth century, British scholars and the public alike celebrated their country’s opposition to slavery as evidence of national virtue, proof that the global impact of British imperialism was a net positive. Writing at the high point of Victorian self-regard, historian W.H. Lecky identified “the unweary, unostentatious, and inglorious crusade of England against slavery… as among the three or four perfectly virtuous pages comprised in the history of nations.”
Scottish moral philosopher William MacAskill agrees with the essence of Lecky’s claim, if not its triumphalist tone. In his recent book What We Owe the Future, MacAskill identifies the late eighteenth-century campaign against slavery as inaugurating one of the most remarkable and “important values changes in all of history.” MacAskill’s interest in antislavery, the subject of the second substantive chapter of his book, is forward looking: he uses the movement as a case study to illustrate the possibilities of collective moral action and the conditions necessary to induce people to expand the scope of their moral considerations. The change in thinking and moral horizons that MacAskill seeks to catalyze in today’s world is to get people to recognize that the wellbeing of future generations matters and, moreover, is largely dependent on our decisions in the present. Put directly, MacAskill’s central argument is that “Future people count. There could be a lot of them. We can make their lives go better.” What We Owe the Future argues for long-term utilitarianism by extending the chronological horizons of the effective altruist movement—of which MacAskill is a founder and leading light—to consider all human beings who will one day be alive. It’s an ambitious aim.
MacAskill is less interested in how the antislavery movement succeeded than in why it emerged in the first place. Specifically, he’s engaged by a question that has captivated scholars for generations: was abolitionism caused by external forces like shifting economic conditions or new intellectual currents, or can the movement be attributed primarily to the efforts of activists? The groundwork for this debate was laid by Eric Williams in his pathbreaking 1944 study Capitalism and Slavery. In it, the future Prime Minister of Trinidad and Tobago argued that Britain ultimately abandoned its slave system due to the declining profitability of its West Indian colonies and the rise of a free-market ideology following American independence. While the first part of this thesis was disproved in the 1970s by research showing that the Atlantic slave economy remained lucrative well into the nineteenth century, the second part was more enduring. This had the effect of focusing scholarly attention on the relationship between antislavery and society-wide changes. Almost all historians operating in Williams’ shadow have had to grapple to some extent with whether slavery was a doomed institution—due to shifts in the structure of the British economy, the diffusion of Enlightenment values, or any other force—whose demise was merely hastened, or whether slavery would have existed for further generations were it not for crusading abolitionists. Indeed, the historiography of antislavery has proven remarkably rich terrain for debating the role of human agency in history.
MacAskill adopts the view that is at least implied in almost all scholarship on abolitionism today: mass opposition to slavery was not inevitable. Rather, “it was the actions of thinkers, writers, politicians, formerly enslaved activists, and enslaved rebels who together brought about the end of slavery.” This conclusion is heavily informed by the argument put forth in Christopher Brown’s 2006 book Moral Capital: Foundations of British Abolitionism. According to Brown, the rhetoric of the American Revolution, centered on slavery and freedom, gave opposition to slavery both a political salience and moral legitimacy it had previously lacked. The conflict also pushed to the fore a litany of questions about the proper ends of empire and structures of imperial rule that did not go away when fighting stopped. The war’s immediate aftermath, therefore, brought a unique set of circumstances that made more Britons more receptive than ever before to proposals to morally reform their empire. Within this milieu, individuals pursuing diverse agendas found in abolitionism a way to further their respective causes, ranging from Evangelicals’ efforts to make piety fashionable to Quakers’ attempts to solidify a denominational identity. Dependent on the “distinct and distinctive” conditions created by the loss of America, the origins of abolitionism were, in Brown’s words, “deeply contingent.”
While MacAskill and Brown emphasize different aspects of contingency—Brown the contingency of the moment, and MacAskill the contingency of the choices of activists—both agree that the right combination of context and individual commitment were necessary for moral change to occur. As MacAskill summarizes, the antislavery movement originated in “a moment of plasticity,” when values were in flux and history could have gone in multiple different directions based on choices made at the time. British society in the decade after the American Revolution has parallels to the world today, when looked at from a long-term perspective. Thanks to rapid advancements in science and technology especially, MacAskill argues that we’re living in a period in which moral values have yet to be “locked in”; what we decide in this generation could well determine the systems, structures, and technologies that will shape the lives of billions of people yet to come. MacAskill does not believe we need new sets of values per se, but rather that we need to end our moral inconsistencies—i.e. behaviors that most of us sense are wrong, yet to which we conveniently turn a blind eye (consuming factory-farmed meat is given as an example later in the book). In this sense, he suggests, the challenge facing MacAskill and other effective altruists is akin to that which faced early abolitionists. Namely, as Brown emphasizes, most eighteenth-century Britons perceived on some level that slavery and the Atlantic slave trade were unethical, but sentiments alone did not lead people to moral action, let alone activism.
There is another more fundamental parallel between what British abolitionists were up against and the task that MacAskill and leading effective altruists have set themselves. Until the late eighteenth century, the biggest barrier to concerted action against the Atlantic slave system was its geographic distance from those European nations that propelled it. In the idiom of the time, slavery exited “beyond the line.” This was a physical and conceptual space where moral standards were comparatively lax and where violence and suffering took place outside the metropolitan gaze. The central question for early antislavery campaigners was how to end this perceptual bifurcation by getting their fellow citizens to see connections between the distant and the near—to understand that their choices could profoundly impact the lives of people with whom they would never have direct contact. This is the same challenge facing all people who promote justice on a global scale. Philosophically, effective altruists have tackled it by arguing through utilitarian logic that all human suffering is equal regardless of where it occurs; there should therefore be no “beyond the line” when it comes to ethical obligations in today’s globalized world. As Peter Singer famously put it in his essay “Famine, Affluence, and Morality,” distance from evil in no way “lessens our obligation to mitigate or prevent that evil.” What We Owe the Future argues that this reasoning should apply temporally, not just geographically. In fact, since utilitarianism demands that we act in a way to maximize the wellbeing of the most people possible, and since there are likely more human beings yet to be born than are alive in the world today, our main ethical obligations are to the future. Part of the appeal of abolitionism as a case study for MacAskill is that campaigners brought about a moral change that has impacted generations of individuals.
It is tempting to draw further comparisons between eighteenth-century abolitionists and today’s effective altruists. As a recent New Yorker profile of MacAskill and the coalescing of effective altruism over the past decade highlights, many within the movement share a strong sense of idealism, a conviction in the righteousness of their cause, a responsibility to align personal behavior with worldviews, and a collective identity forged through these commitments. The same could be said for many of the progenitors of antislavery. Such similarities raise questions about what lessons effective altruists could learn from the history of abolitionism about growing a social movement and convincing people to care about the wellbeing of those distant from them. Since the publication of Moral Capital over fifteen years ago, researchers have increasingly focused on recognizing the diversity of the antislavery coalition and the ways in which activists—both Black and White—employed discourses of gender, race, sentiment, and identity to advance their cause. This decentering of the field suggests the utility of thinking about overlapping abolitionist movements as opposed to a single, unified movement. Would greater engagement with this scholarship lead MacAskill to draw tactical lessons from the how of antislavery, beyond the contingency of the why and when of antislavery?
There is, however, one lesson from the course of the antislavery movement that MacAskill explicitly applies to his campaign to spread long-term utilitarian thinking, values, and behaviors. This lesson is more motivational than strategic. Namely, moral progress requires an uncompromising willingness to promote heterodox ideas even in the face of intense ridicule. Here, MacAskill holds particular esteem for the Quaker dwarf Benjamin Lay, who over the 1720s witnessed the horrors of slavery firsthand in Barbados and proceeded to commit himself wholesale to convincing his coreligionists to turn against the institution. Lay’s tactics were eccentric and exasperating to those around him; they often involved guerrilla theatre to dramatically call out the iniquities of slave owners. Yet though seen as a gadfly and an oddball and mocked in his day, history has proven Lay to be a moral visionary whose ethical commitments were ahead of their time. That MacAskill keeps a picture of Lay on his desk reflects his belief that long-term utilitarianism is still in its infancy—a mindset and movement that is winning small numbers of converts but will have to wait for mainstream uptake. Perhaps it also reveals something about where MacAskill sees himself in that movement.
Matthew Wyman-McCarthy received a PhD in History from McGill University and subsequently completed postdoctoral fellowships at Columbia University and the University of New Hampshire. His research on slavery, antislavery, and comparative imperialisms has appeared in publications such as the Journal of British Studies, Slavery & Abolition, and History Compass. He works as a grant developer and freelance academic editor in Ontario, Canada.
 Following the lead of scholars in the field, MacAskill distinguishes between abolitionism as a social movement that burgeoned in late eighteenth- and early nineteenth-century Britain, and the actual abolition of slavery and the slave trade in the Atlantic World over the same period. The former story centers largely, though not exclusively, on White Britons who in many ways benefitted from the Atlantic slave system. The latter involves a wider and more diverse set of actors, most saliently enslaved and formerly enslaved individuals in the Americas who undermined the system in ways both big and small.