In the summer of 1550, Charles V, the King of Spain, ordered a group of fourteen officials, scholars, and clerics to judge a dispute. The conquest of the Americas had swept on for over half a century, but a debate was stirring within Spain – were the wars in the New World unjust? During a month of meetings, the judges heard and discussed opposing arguments: Juan Gines de Sepulveda, a noted Renaissance scholar, argued that the Spanish could legitimately enslave the Native Americans (or “Indians”) because they were “natural slaves,” and that the wars of conquest were justified both by the Indians’ barbarism and idolatry, and by the imperative to spread Christianity. The Dominican Friar Bartolemé de Las Casas (1474–1566) spoke for five days in defense of the Indians, arguing on both ethical and theological grounds that the conquistadors’ conquest and enslavement of the natives was gravely wrong.Footnote ¹

Both Sepulveda and Las Casas thought religion was firmly on his side on the slavery question. The same was true of the Jewish Rabbi Morris J. Raphall and his critic Rabbi David Einhorn, in Civil War-era America. Both thought that Judaism was on his side, as Morris defended slavery with religious arguments and Einhorn argued for abolition with religious arguments. And the same was true in the early twentieth century as Muslim thinkers debated whether Islam required that slavery continue or provided an imperative to end it.

From the beginning of human history, slavery and religion have been linked. Slaves have been forced to serve religious hierarchies, even to the point of ultimate sacrifice. Religious doctrine has often set out who might be enslaved and justified that slavery. Yet religious ideas and motivations also led people of faith to restrict the scope of slavery and ease the lives of slaves in ages past, and religious groups were at the center of the successful abolitionist movements of the eighteenth and nineteenth centuries. Unknown to many, the tangled and varied connections between religion and slavery continue today. Religious groups play a vital role in the fight against contemporary slavery, yet religious identity is still being used to facilitate enslavement, in many ways and in many countries.

The academic literature on slavery is vast, including thousands of articles and books on slavery as it relates to particular religious traditions in particular periods or societies. Surprisingly, there is no single work that synthesizes this prior work and analyzes the common patterns in the relationship between slavery and religion that appear with a bird’s eye view. There is also a sizable literature on contemporary slavery, yet little has been written on the important and fascinating connections between religion and contemporary slavery. In this book we attempt to fill both these gaps, focusing principally on Judaism, Christianity, and Islam, but with some treatment of Hinduism, Buddhism, and several other religions. In Part I, we examine the ways in which religious groups and religiously inspired individuals have responded to slavery in the past. In Part II, we turn to the relationship between religion and slavery in the present.

Part I consists of four chapters, on religious attempts to justify slavery, to ameliorate or ease the lives of slaves, to restrict slavery without at the same time seeking to eradicate it, and to abolish slavery. Chapter 2, on the justification of slavery, includes a detailed discussion of religious proslavery arguments, as well as our own critiques of those arguments. Chapter 3 examines attempts by religious groups or individuals to make the lives of slaves better in some way, but without challenging the legitimacy of slavery as such. We organize these attempts into four categories: (i) moral exhortations to treat slaves well, (ii) exhortations to manumit or ransom slaves, (iii) legislation aimed at easing the lives of slaves, and (iv) promulgation of doctrines of spiritual equality and shared eternal destiny that likely promoted the welfare of some slaves. Chapter 4, on restricting slavery, reviews religious attempts to reduce the scope of slavery that fall short of abolition. For example, religious groups at various times have restricted slavery by making it more difficult to turn a free person into a slave, and by making it more difficult to sell slaves, and by placing limits on who could hold a slave of a certain category. In this chapter we also evaluate the influence of religion in the waning of slavery in medieval Europe. Chapter 5 is an overview of the religious rejection of slavery. We discuss early antislavery voices, such as the Essenes and St. Gregory of Nyssa (c. 335–395 AD), and tell the story of the Christian rejection of slavery in the seventeenth and eighteenth centuries. The chapter closes with an overview of Islamic abolitionism in the nineteenth and twentieth centuries.

Part II focuses on the relationship between religion and slavery in the present and recent past. In Chapter 6, we provide context by sketching the evolution of slavery and the development of antislavery efforts from after the American Civil War until the late twentieth century, including discussions of the antislavery movement focused on the Congo around the turn of the twentieth century, the persistence of slavery in various European colonies, and the use of state-organized slave labor by Axis powers during World War II. Chapter 7 is an examination of the ways in which religion is still being used to facilitate slavery. We describe the use and justification of slavery by the Islamic State of Iraq and Syria (ISIS), trokosi slavery in West Africa, and temple slavery in India. We also show how the religious identity and beliefs of victims are sometimes used to trap them in slavery. Finally, in Chapter 8, we show how religious groups are helping in the fight against contemporary slavery, and ask how they might help more.

1.1 How Bad Was Ancient Slavery?

For religious believers, it can be painful to learn how one’s own religious tradition has justified the practice of owning and exploiting human beings. A natural response is to wonder just how bad slavery was in the ancient contexts in which the major religions permitted it. Life was hard back then … weren’t ancient slaves basically just dependent family members, living a totally different reality than the kidnapped and brutalized Africans worked to death on the sugar plantations of the New World in more recent centuries? In a word, no. While it is certainly true that the slavery of the sugar plantations was particularly brutal, and that in any age slaves have experienced a wide variety of conditions, an examination of historical evidence indicates that for the vast majority of slaves in ancient times, slavery was very harsh indeed. As a scholar of ancient slavery explains:

Classicist Richard Saller, speaking of Roman slavery, writes that “The lot of bad slaves was to be beaten and that of good slaves was to internalize the constant threat of a beating.”Footnote ³ In the words of another historian:

Some slaves had it far better than others, but in all but the most exceptional cases, to be a slave was to be controlled by violence or the threat of violence, and exploited as a tool for the benefit of others.

1.2 How Bad Is Modern Slavery?

Similarly, it’s natural to wonder how bad “modern slavery” really is. When we speak of modern slaves, are we simply talking about people who, because of poverty, find it necessary to work under extremely demanding conditions? Again, the short answer is “no.”

In the present moment, though it is hard to imagine, slavery is equally if not more brutal and deadly than it has been in the past. A key reason for this is the complete collapse of the monetary value of slaves. In the mid nineteenth century a healthy young male slave in the United States had an average “sale” price that, in today’s money, would be around £40,000/$50,000. Today, slaves practically cost nothing or very little. The large number of vulnerable people, especially in poorer countries, means that men, women, and children are easily lured into bondage – their own desperation pushing them to accept false job offers. Once removed from their community, those lured into slavery are treated as disposable inputs, to be used up and discarded. They can be worked until they collapse, and then they are dumped or killed. Significant numbers of people are enslaved within armed conflict. On the day this is being written, there are fifty-six ongoing conflicts, the largest number since the end of World War II. Most of these conflicts are occuring in Africa and the Middle East, where enslavement in war is most common. Research on conflicts occurring between 1989 and 2016 found several forms of enslavement occurring in 78 percent of all conflicts.Footnote ⁵

While slavery is illegal in most countries, and very much prohibited by international agreements and United Nations conventions, the efforts of criminals, the deadly impacts of climate change and environmental destruction, the intentional impoverishment of minority groups, and the assaults on the lives and livelihoods of people because of their particular religious or tribal affiliation, can all lead to the loss of freedom and enslavement, if not worse.

As a hidden crime, it is not possible to determine the precise number of people in slavery around the world – but years of work by antislavery organizations and scholars have produced estimates ranging up to 50 million slaves, with the caveat that because slavery is often a hidden crime and occurring in remote areas no estimates are fully precise.

1.3 What Do We Mean by “Slavery”?

As discussed in Chapter 6, the League of Nations 1926 Convention to Suppress the Slave Trade and Slavery included a definition of slavery that has proven applicable today: “Slavery is the status or condition of a person over whom any or all of the powers attaching to the right of ownership are exercised.” And as explained in the Bellagio-Harvard Guidelines, the right of ownership “should be understood as constituting control over a person in such a way as to significantly deprive that person of his or her individual liberty, with the intent of exploitation through the use, management, profit, transfer or disposal of that person. Usually this exercise will be supported by and obtained through means such as violent force, deception and/or coercion.”Footnote ⁶

The fundamental fact of slavery, past and present, is that a person is reduced to “property” and may be used, abused, exploited, bought, sold, or killed. Slaves today, because they tend to be much less costly than slaves in the past, are normally treated as disposable inputs in criminal activities.

1.4 Using Slavery

In Part I, we examine four major responses by religious groups to human bondage: justifying, ameliorating, restricting, and rejecting slavery. Space constraints inclined us to forgo coverage of a fifth response, using slavery, but we say a few words about it here.

Many religious groups have used slave labor to support their material needs. There are many references to Catholic clergy owning slaves in the early medieval period, for example. Buddhist monastic estates and Confucian academies used slaves for food production and the performance of manual labor.Footnote ⁷ Certain Islamic societies made extensive use of slaves within their armies.Footnote ⁸ At several points in history, moreover, religious groups have used slaves for specifically religious purposes. In ancient Sumeria, temple slaves were used “to assist priests” in their functions, and the earliest evidence of Greek slavery includes references to two categories of slaves: those owned by individuals and “slaves of the god.”Footnote ⁹ In the religious system of trokosi in West Africa, young girls are given as slaves by their families to fetish priests, in atonement for offenses committed by male relatives or ancestors. (As we’ll discuss in Chapter 7, this practice has continued into the present day.) Perhaps the most shocking example of the religious use of slaves was as victims in ritual human sacrifice, which was practiced in many ancient societies. Two common motivations were a belief that a dying king or other important person needed attendants in the next life, and a desire to please the gods so that the crop cycle might not cease.Footnote ¹⁰ In some societies, slaves and war captives were used as the victims.Footnote ¹¹ Tribute slaves from north of the Aztec Empire could end up as victims sacrificed to the Aztec gods.Footnote ¹² In Benin (West Africa), slaves were killed to ward off plague, and in pre-Christian Europe, “Norsemen and Teutons regularly sacrificed war prisoners to their gods.”Footnote ¹³ In such cases, the victims satisfy the definition of slavery laid out in the Bellagio-Harvard Guidelines: They were controlled “in such a way as to significantly deprive” them of “individual liberty, with the intent of exploitation through” their use as sacrificial victims. In this case, the “use” was for a specifically religious purpose.

Much more could be written about how religious groups have used slavery, but in this book we focus on more explicitly evaluative responses: When have religious groups thought slavery was acceptable, thus justifying it, and when have they thought it was wrong, thus rejecting it? And when have they recognized its problems without yet rejecting it outright, thus attempting to ameliorate the lives of slaves or restrict the institution? We begin with the story of the religious justification of slavery.