1. Prelude: Colonial Slavery from Kant’s Standpoint

Colonial slavery is the chattel slavery instituted in the Americas during the sixteenth through nineteenth centuries, plus the transatlantic slave trade associated with it. Thomas Clarkson, the most tenacious and prolific British abolitionist, had this combination in mind when he wrote in 1786:

Having refuted all the standard defenses of colonial slavery, Clarkson confronted the “receivers” of slaves: “by what right you reduce them to so wretched a situation?” They might respond: We bought them! “It is not your money,” Clarkson countered, “that can invest you with a right”; for the commerce upon which the pretended right was founded was “contrary to the principles of law and government, the dictates of reason, the common maxims of equity, the laws of nature, the admonitions of conscience.” The enslaved Africans “have a right to resist” because “every lash that you give them is unjust” (Clarkson, Reference Clarkson1786, pp. 239–42).

Kant never censured colonial slavery in similar terms, despite being proficient in the language of right, law, moral conscience, and the dictates of reason. This normative silence was not due to ignorance. As we shall see, Kant was familiar with the basic workings of colonial slavery, cognizant of its geopolitical implications as well as economic significance, and well-versed in the attendant racism. He also benefited from it materially, albeit indirectly. So, one can say that he chose not to join the likes of Clarkson in denouncing colonial slavery as unjust.

Granted, Kant belatedly expressed some qualms about colonial slavery. But they were not about whether it wronged the enslaved humans by violating their rights. Describing the Sugar Islands in the West Indies as “that place of the cruelest and most calculated slavery” in “Toward Perpetual Peace” (1795), Kant was primarily worried about the implications for intra-European politics: slavery in that part of the world served “only a mediate and indeed not very laudable purpose, namely, training sailors for warships and so, in turn, carrying on wars in Europe” (ZeF, 8, 359). In the Doctrine of Right (part II of The Metaphysics of Morals, 1797), Kant used “the Negroes on the Sugar Islands” as a cautionary tale to illustrate what would happen if a master in a civil society—in relation to a contractually hired servant (subiectus)—were “authorized to use the powers of his subject as he pleases”: the master would then be licensed to exhaust those powers “until his subject dies or is driven to despair” (MS, 6, 330).Footnote ¹ If both texts convey a sense of unease about how slavery was practiced in some places (there is no mention of slavery in the newly independent United States), this is far from condemning the very institution of slavery. What Kant did not say is as telling as what he did say: at a time when he theorized systematically about “right,” including the “innate right” to freedom that “belongs to everyone by nature” (MS, 6, 237), he did not ask whether colonial slavery violated the enslaved persons’ natural rights (Lu-Adler, Reference Lu-Adler2025a).

Meanwhile, in a section of the Doctrine of Right called “What Is Money?” Kant nonchalantly mentioned Negro slaves (Negersklaven) on the Coast of Guinea—the so-called Slave Coast (Dohna mns, 234)Footnote ²—as an example of “goods” that became money or “a lawful means of exchange of the industry of subjects with one another.” With such goods, one person’s demand would move another to “industry in procuring” them (MS, 6, 288). The greatest demand for African slaves in the eighteenth century came from the Sugar Islands. The adoption of sugar cultivation in the West Indies was so catalytic that historians call it “the sugar revolution” (Higman, Reference Higman2000). It supercharged the transatlantic slave trade: the growth of sugarcane was so harsh and dependent on large-scale forced labor that it necessitated an enormous supply of slaves from Africa.

As Kant told his students in 1792, “the sugar cane has to grow for sixteen months before it can be cut. The Negroes here have to work everything, turn the mill, boil the raw sugar” (Dohna mns, 193). The work was grueling and dangerous. So, in the British Barbados, for instance, the slave population was “under a necessity of being entirely renewed every sixteen years” (Burke & Burke, Reference Burke and Burke1760, p. 122). Barbados was not even the worst. According to the formerly enslaved British abolitionist Olaudah Equiano, on this island, “slaves meet with the best treatment, and need fewest recruits of any in the West Indies” (Equiano, Reference Equiano2003, p. 106). Kant was right to describe slavery on the Sugar Islands as “most calculated.” Part of the calculation was that, as long as there was a constant import of cheap slaves, it was more economical to work the existing slaves to death and replace the casualties with a new stock of fungible human “goods” than invest in their health and safety.Footnote ³ Keep that in mind, add all the Sugar Islands together, and you can imagine the insatiable demand for new slaves. This was what incentivized traders to procure a steady supply from places like the Slave Coast. Indeed, at least over 2.2 million Africans were forced onto ships destined for the Sugar Islands between 1751 and 1800.Footnote ⁴

The brutality of colonial slavery was well known among European elites long before Kant mentioned it. Admissions of its brutality rarely came with a full-throated rebuke of the institution itself, however, let alone a clarion call for its abolition. Edmund Burke, for example, used the above-mentioned statistics about Barbados to demonstrate that “some uncommon and insupportable hardship lies upon the negroes,” resulting in a “prodigious waste” of this necessary source of labor (Burke and Burke 1757, pp. 120–21). He was thereby making an economic case for regulations to make the practice of slavery less wasteful (and hence more sustainable).

Burke, as we shall see later, did acknowledge that colonial slavery was immoral per se. But it was not uncommon for an eighteenth-century thinker to hold two thoughts at once—that colonial slavery was morally disastrous, and that it was a hopelessly entrenched economic reality (implying that it would be impractical to seek its abolition, at least not immediately). Take Voltaire, for instance. His Candide (first published in 1759) includes a famous depiction of the barbarity of slavery. A maimed slave in the Dutch Surinam explained what happened to his limbs:

The last line of this testimony pithily connects sugar consumption in Europe to the slave labor behind it. Later, in a study of the French colonies in the West Indies, Voltaire presented this connection as a political-economic reality. The study began with a list of France’s most consequential acquisitions, including “one half of the island of St. Domingo, the islands of Martinico, Guadeloupe, and some of the Lesser Antilles” (1901, p. 251). These islands, Voltaire reported, “produced in France an annual circulation of near 60 millions in merchandise.” French Saint-Domingue (later Haiti) was especially significant (it would become the most profitable colony in the world).Footnote ⁵ As of 1757, this part reckoned “100,000 slaves, blacks and mulattoes, who work in the several plantations of sugar, cocoa, and indigo; and who sacrifice their lives and healths to please those new-acquired wants and appetites which were unknown to our forefathers.” In this way, a “superfluity” that had become a “necessity”—plus the “dear rate” that France would have to pay to import it from other countries—served to perpetuate slavery in the French colonies (1901, pp. 258–59).

These comments suggest that the economy of colonial slavery was intertwined with politics, including competitive intra-European politics. Kant was somewhat attuned to this historical reality. He was aware that leading colonial empires like Britain and France relied on the vast number of slaves for their national wealth. French Saint-Domingue had become “far more important,” Kant informed his students in 1792, than other Sugar Islands. The number of slaves on this island had more than tripled since Voltaire did the counting, to 350,000. Kant found this number significant because it was “the true measure of wealth” (Dohna mns, 241). As we shall see, this wealth mattered because it determined the relative power a nation like France had vis-à-vis its rivals. It also meant that no one would want to abandon the business of slavery unilaterally (as long as it remained lucrative).

Importantly, the dividends from colonial slavery went far beyond what the colonists could squeeze out of slave labor. It was a boon to countless ancillary businesses. Kant alluded to one obvious example: the raw sugar—the “reddish-brown stuff” ( Muskebrode )—produced on the Sugar Islands had to be refined into consumable “powdered sugar, sugar candy” in Europe (Dohna mns, 193). As a result, countless sugar refineries emerged in European coastal cities, including Kant’s Königsberg. Roughly a quarter of Kant’s own invested wealth was in the Königsberg Sugar Refinery (established in 1782), which processed raw sugar from the Sugar Islands.Footnote ⁶ This was just one example of how slave labor, through a complex mediating structure, became pivotal to European prosperity. Although Kant’s Germany did not yet have its own colonies, it benefited from colonial slavery through a nexus of trading houses, merchants, investors, manufacturers, and so on (Raphael-Hernandez & Wiegmink, Reference Raphael-Hernandez and Wiegmink2017). One can only imagine how much more deeply invested leading colonial empires like Britain and France would be in the business of slavery and how the political-economic considerations could outweigh any moral misgivings the politicians or citizens of Europe might have about it.

In what follows, I shall further explain the political economy of colonial slavery (Section 2). This helps to contextualize Kant’s scattered remarks about colonial slavery as well as his indirect financial entanglement with it. Once we recognize that colonial slavery was pivotal to the economic development and political dynamics in eighteenth-century Europe, we will also understand the basic forces that sustained it for so long: state powers (aligned with the interests of economic elites) and a majority of the citizenry willing to go along based on perceived (personal or national) material interests. I will then use the notion of racial capitalism to introduce a further obstacle to the liberation of enslaved “Negroes”: a racial ideology emerged from the practices of colonial slavery to justify their (continued) enslavement. Kant channeled this ideology by racializing the “Negro” as naturally suited for the kind of slavery practiced in the West Indies (Section 3).

My ultimate goal is not simply to fault Kant for remaining silent about the injustice of colonial slavery, propagating its ideological underpinnings, or indirectly profiting from it. By spotlighting and contextualizing his silences, assertions, and practices vis-à-vis colonial slavery, I aim to reveal certain material, political, and ideological obstacles to liberatory causes in a world transformed by colonial slavery. On that basis, I query the viability of a radical-liberal reading of Kant’s political philosophy that attempts to disentangle its theoretical core from his anti-Black racism (Section 4).

2. The Political Economy of Colonial Slavery

In a study of the British abolitionist movement, historian Adam Hochschild talks about the difficulty of getting people in the metropole to care about “someone else’s rights” (Hochschild, Reference Hochschild2005, p. 5). One problem is the literal distance from those whose rights are violated. As the French Enlightenment philosopher Condorcet suggested on the occasion of announcing the rules for the French abolitionist society Société des Amis des Noirs (established in 1788), one could hardly direct “the public’s attention towards the picture of misfortune” when enslaved humans were “being sacrificed far away.” This problem was compounded by two factors: first, an intricate political-economic structure linked the oppression of those humans with “powerful political interests”; second, the “blind force of prejudice” about them meant that Europeans felt little affinity toward them. So, it would be a herculean task to restore the “sacred human rights” of “an entire race … crushed beneath the weight of its chains” (Condorcet Reference Condorcet2012, p. 148). Indeed, the short-lived Société failed to generate much enthusiasm for abolition in France “mostly due to” the citizenry’s genuine lack of interest in or even antagonism to abolition: “The planters and those engaged in the slave-trade proved to have more clout” than the intellectual elites of the Société (Popkin, Reference Popkin1992, p. 60).

I will talk about the racial “prejudice” later, because we cannot fully grasp its significance without first attending to the historical-material conditions that gave rise to it. To this end, political economy is the most fitting “mode of analysis” (Tran, Reference Tran2021, p. 8n.21). “It’s the economy, stupid,” as the American political strategist James Carville famously said (Rosenberg, Reference Rosenberg2024). A similar perception helped to sustain colonial slavery. Hochschild imagines that, if “you had stood on a London street corner and insisted that slavery was morally wrong and should be stopped” before the abolitionist movement gained momentum in the late 1780s,

So, economic self-interest, not moral conscience, tends to hold sway in deciding what to do about an institution that drives a nation’s prosperity with the sweat and blood of enslaved humans.

In that case, it may not be enough to make people see “connections between the near and the distant” and recognize that their daily consumption involves “labor in another corner of the earth” (Hochschild, Reference Hochschild2005, p. 6). A humanitarian may use the most vivid and morally charged language, as Claude-Adrien Helvétius did in his De l’esprit (Helvétius, Reference Helvétius1759), to show that “every hogshead of sugar landed in Europe must be allowed to be dyed with human blood” and implore the public to “renounce” the pleasure of sugar out of “a love for all our fellow-creatures” (Helvétius, Reference Helvétius1759, 14n.). While De l’esprit “enjoyed a remarkable succès de scandale ” and evoked “universal public interest” (Smith Reference Smith1964, 332), the remarks about slavery apparently did not gain immediate attention. The imagery of blood-stained sugar received a popular uptake only decades later, through a widely circulated anti-slavery pamphlet by the British abolitionist William Fox. Fox even quantified the human suffering behind the sweet pleasure: “in every pound of sugar used, (the produce of slaves imported from Africa) we may be considered as consuming two ounces of human flesh” (Fox, Reference Fox1792, p. 5).

Those vivid, moralistic campaigns might have played a role in the eventual abolition of colonial slavery by activating public sentiments against it (Oldfield, Reference Oldfield1998). As Eric Williams has famously argued, however, their role may have been “grossly exaggerated” (Williams, Reference Williams2021, p. 143). Britain abolished the slave trade in 1807 and slavery in its West Indian colonies in 1833, mainly because the material conditions were ripe.Footnote ⁷ The interest of the economic elites determined the fate of British West Indian slavery at every juncture:

Even most of the abolitionists (excepting Clarkson) “took the side of the capitalists,” in deed if not in word. If the desire for cheap sugar eventually doomed the West Indian colonies (the colonists’ insistence on monopoly drove up the price of raw sugar for British refineries), the same desire “overcame all abhorrence of slavery” after 1833: the abolitionists did not object to Britain profiting from slave-grown sugar of Brazil and Cuba (or slave-grown cotton of the United States), which was as much “dyed with the Negro’s blood” as the slave-grown equivalent from the West Indies they once boycotted. So, their humanitarian aspirations were limited and contingent on evolving material conditions (Williams, Reference Williams2021, pp. 152–54).Footnote ⁸

People in power tend to bracket moral concerns when material conditions do not seem ripe for addressing them. Writing to address the abolitionist pressure in 1792, Edmund Burke acknowledged that colonial slavery per se was a moral evil deserving “utter abolition.” This evil had become “incurable,” though, being “a system made up of a great variety of parts.” If descending into this moral abyss was easy, climbing out of it would be onerous. The most practical path was to “take our point of departure from a state of Slavery” and “make it as small an evil as possible” through judicious regulations (Burke, Reference Burke1999, pp. 255–59; see Marshall, Reference Marshall2019, pp. 177–201). The motivation behind this reformist proposal was hardly moral. It was all about protecting the empire’s material interest as well as Burke’s own (O’Neill, Reference O’Neill2020). As he wrote decades prior, if “Negroes” must be “ruled with a rod of iron” for being “stubborn and intractable for the most part,” they should not be “crushed with it.” Enough of them had to be kept alive to churn the economic machine that depended on their labor. Moreover, a less brutal treatment presumably meant fewer slave revolts and greater stability: “those nations which have behaved with the greatest humanity to their slaves, were always best served, and ran the least hazard from their rebellions” (Burke & Burke, Reference Burke and Burke1760, p. 128).

As an MP, Burke once represented Bristol, a city that had rapidly expanded and prospered thanks to its involvement in colonial trade. Although this political representation was brief (1774–80) relative to Burke’s long career in Parliament (1765–94), his connection to Bristol was formative. As PT Underdown explains,

Bristol, Underdown adds, “was then the second city and port of the kingdom, for her wealth was largely derived from her colonial trade.” Thanks to their wealth, the merchants who “acquired great prosperity” from that trade also held sway over who should represent Bristol in Parliament. Burke must be attuned to this link between wealth and politics (Underdown, Reference Underdown1961, p. 4).

A key part of Bristol’s colonial trade was the African trade, the first leg of the triangular trade that connected Europe, Africa, and the Americas. As ships left Bristol for Africa, they carried British products to barter for slaves; next, they sailed toward the colonies in the Americas (primarily the West Indies), where the slaves who survived the hellish Middle Passage were traded for colonial goods, such as raw sugar, to be sold in England. This picture resonates with Kant’s observation that African slaves functioned as “money” in trade. There was profit to be made at each juncture of the trade. So, Bristol “grew rich on the slave trade.” Although it was probably “never the principal slave port of the kingdom,” it would remain “the only outport that was largely concerned in the African trade” well into the eighteenth century (MacInnes, Reference MacInnes1968, p. 6; see Richardson, Reference Richardson2005, pp. 36–8).

The African trade bolstered a nexus of ancillary businesses and industries in Bristol. These included, to name just a few, insurance agencies underwriting human and nonhuman “cargos” alike (Oldham, Reference Oldham2007), manufacturers of trade goods, shipbuilders, and workshops that prepared ships for the long voyage (Dresser, Reference Dresser2016, pp. 29–31). The city’s livelihood thus depended on the trade. This dependence was already significant in the early eighteenth century (Bristol began legally trading slaves in 1698, after the London-based Royal African Company lost its monopoly). So, when the Royal African Company threatened to reassert its monopoly in 1713, Bristol’s city council protested:

Indeed, Bristolians from all walks of life “stood to make some money from the African trade” and thus “had a vested interest in the trade.” They could be people doing the most mundane work, from “the various small retailers who provided meat and bread to feed the crew and the horsebeans to feed the slaves” to “the women who did the captain’s laundry and the men who cleaned the ships on their return” (Dresser, Reference Dresser2016, p. 31). Even in the late 1780s, when Bristol’s investment in the colonial trade had already passed its peak, 40% or more of its income “may have arisen directly from activities linked to slave economies”; and this does not even take into account derivatives like interest on loans to planters (Richardson, Reference Richardson2005, pp. 47–49). So, when the Quaker poet Robert Lovell wrote Bristol: A Satire in 1794, he depicted a bustling city where a single-minded preoccupation with trade had vanquished all “nobler cares of mind,” “soft humanities,” and “sympathetic feeling.” The city was drowned in humdrum chatter about the prices of colonial goods, the arrival of ships, and the stock market. It had “no sorrow while its wealth’s secure.” And the “sons of trade” joined forces with the “sons of power” to defend “‘The right’ and privilege ‘of doing wrong’,” to wield their power “Not to guard freedom, but to save expence,” and to appease (or oppress) ordinary citizens and keep them quiet (Lovell, Reference Lovell1794, pp. 10–17). Citizens whose livelihoods hinged on the business of slavery were easy to mollify.

Abolition was hardly imaginable when its perceived cost was tremendous. Referring to Liverpool, which had become the “slaving capital of the world” by 1785 (Moody, Reference Moody2020) and controlled 80% of the British slave trade and nearly half of the European slave trade in the 1790s (Morgan, Reference Morgan, Richardson, Tibbles and Schwarz2007), Williams writes:

This sentiment must have resonated broadly, considering that “by 1750 there was hardly a trading or a manufacturing town in England which was not in some way connected with the triangular or direct colonial trade” (Williams, Reference Williams2021, p. 40; see 39–66). Indeed, “all classes in English society presented a united front with regard to the slave trade” through most of the eighteenth century (Williams, Reference Williams2021, p. 29). This consensus was in no small measure a result of “the powerful West India interest” that consisted of “two forces, planters and merchants, coupled with colonial agents in England”: “In the classic age of parliamentary corruption and electoral venality, their money talked” (Williams, Reference Williams2021, p. 73; see Higman, Reference Higman1967).

Here we have a case of economic elites capturing political power and wielding it to uphold a structure of domination that served their interests. Colonial slavery was a legally sanctioned institution: enslaved humans were codified as private property and protected as such by governments; planters and merchants therefore felt entitled to possess and trade those commodified humans and the fruits of their labor; they would never give up such perceived “rights” willingly or peacefully. As Adam Smith explained in his jurisprudence lectures from the 1760s,

If slave labor begets wealth for the free subjects of a state, this wealth in turn serves to perpetuate slavery. By this logic, the wealthier and politically freer a nation is, the worse and more entrenched its slavery becomes. In a state that enjoys both “opulence and freedom,” it is unlikely that slavery will ever be abolished: “the legislators are here persons who are each masters of slaves; they therefore will never incline to part with so valuable a part of their property” (Smith, Reference Smith1978, pp. 185–86).

Smith speculated that slavery might be less cruelly practiced in an absolute monarchy: “the monarch here being the sole judge and ruler, and not being affected by the easing the condition of the slaves, may probably incline to mitigate their condition.” Even in this case, however, the authority of the monarch is limited to “the mitigating of the condition of slaves,” not “so far as to abolish slavery altogether” (Smith, Reference Smith1978, p. 187). A sovereign would maintain this institution as long as the kingdom depended on it as a significant source of wealth and relative power vis-à-vis other nations. In Section 1, I mentioned Voltaire’s observation that France needed its own colonial slavery to maintain a competitive advantage in the sugar trade. I also mentioned Kant’s claim that the number of slaves on the Sugar Islands was the true measure of wealth. Wealth matters, however, only because it is a major source of political power. It was this entanglement of wealth and power that made the abolition of colonial slavery seem unlikely.

Jacques Necker, the French finance minister under Louis XVI, illustrated this point in De l’administration des finances de la France (Necker, Reference Necker1784). Necker listed the number of slaves in the French West Indies in the late 1770s. The sum was nearly half a million, half of which belonged to Saint-Domingue alone. Necker lamented that “it is by the number of the unfortunate that one measures their fortune” and called this a “profound subject for reflection.” But he also recognized that economic interests and competitive intra-European politics dimmed the prospect of abolition. A nation’s wealth being the chief foundation of its political power, “the Sovereign most sensitive to the duties of humanity would not want to renounce the services of slaves in its colonies alone.” As long as slave labor and free labor had significantly different prices, this difference “would give such a commercial advantage to the nation that had preserved its old habit [of slavery] that one would soon be discouraged from wanting to surpass it in virtue.” So, the commercial states would have to form a “general pact” to “renounce the slave trade by one common accord”; this would preserve their current positions relative to one another since “only comparative wealth matters in calculations of power” (Necker, Reference Necker1784, pp. 314–319, emphasis added).

To dim the prospect of abolition even further, there was a burgeoning anti-Black ideology that rendered “a small difference in hair or skin color … enough to change our respect [for the nobleness of man] into contempt and make us place beings similar to us in the rank of unintelligent animals, on whose head we impose a yoke” (Necker, Reference Necker1784, p. 318). But even this ideological development was ultimately rooted in material interests. As the French abolitionist thinker Louis de Jaucourt put it bluntly in 1765, “the Christian powers” did not judge that “the slavery of negroes” was incompatible with a religion that preached universal brotherhood and universal love, because “they needed them for their colonies, their plantations, and their mines.” Thus, it all came down to the “accursed hunger for gold” (Jaucourt, Reference Jaucourt and Zemanek2009). As Montesquieu satirized this economic motive in De l’Esprit des lois (1748), a major inspiration for Jaucourt’s abolitionist thinking,Footnote ⁹ the enslavement of Black Africans was, first and foremost, about finding cheap labor to cultivate the stolen land in the Americas.

So, the original reason for “Negro slavery” was economic efficiency: it was necessitated by an economy built on extractive uses of newly colonized land, the purpose of which was to produce raw goods as abundantly, cheaply, and profitably as possible; if, “as compared with [American] Indian and white labor, Negro slavery was eminently superior” from this perspective, the colonists would naturally seek a hefty supply of enslaved “Negroes” (Williams, Reference Williams2021, p. 14). This, as I pointed out earlier, was the demand that supercharged the transatlantic slave trade, in which “Negro slaves” functioned as “money” (as Kant observed).

The enslaved “Negroes” would then be racialized “to justify a simple economic fact: that the colonies needed labor and resorted to Negro labor because it was cheapest and best.” Accordingly, Black bodies would come to be associated with “superior endurance, docility, and labor capacity” (Williams, Reference Williams2021, p. 14, emphasis added). A racist ideology thus emerged from and then helped to sustain a global economy that revolved around colonial slavery. The next section takes a closer look at this ideological move through the lens of “racial capitalism.” We shall see that Kant’s racialization of the “Negro” well accorded with the economic fact just mentioned: it was primarily about what kind of labor this putative race was capable of.

3. Racial Capitalism and Kant’s Racialization of the “Negro”

The preceding account of colonial slavery was inspired by three core hypotheses of Eric Williams’s Capitalism and Slavery (first published in 1944). William Darity summarizes them as follows in a foreword to the book: first, the British abolition was primarily “a matter of calculated economic and strategic self-interest on the part of British officialdom” (this means that Britain would maintain colonial slavery as long as its economic benefits outweighed its moral and many other costs); second, colonial slavery was the “material foundation” for a racist ideology that “arose to provide a potent rationalization for a wholly immoral but economically lucrative practice”; third, colonial slavery “fueled British industrial development” and was “the foundation of British capitalism” (Williams, Reference Williams2021: pp. 11–12).

The combination of the second and third hypotheses points to “racial capitalism.” Cedric Robinson popularized this concept with his Black Marxism. He introduced the concept this way:

One insight here is that racialism, once taken root, would become a “material force” exerting its own agentic power over historical developments. For sure, its emergence in the West—as “the legitimation and corroboration of social organization as natural by reference to the ‘racial’ components of its elements”—was historically contingent. But, once it was codified “into Western conceptions of society” and became “part of the inventory of Western civilization,” it would have “enduring consequences” and “reverberate within and without, transferring its toll from the past to the present” (Robinson, Reference Robinson2021, p. 4).Footnote ¹⁰

Just as important is the fact that behind racial capitalism is a political state maintaining and stabilizing the dominative social structures through “practices of supposedly rational violence (military, security, and legal)” (Melamed, Reference Melamed2015, p. 77). This political dimension of racial capitalism was especially prominent in the context of colonial slavery. Here is how Catherine Hall puts it in her account of racial capitalism through a case study of Jamaica and its most famous planter, Edward Long, whose three-volume work The History of Jamaica (1774) crystallized British racism:

By thus focusing on “the power of the state … in creating and supporting” colonial slavery as a “particular form of racial capitalism,” Hall clarifies that the violence against Black bodies was not just a matter of greedy slavers acting inhumanely: it was “systematic, the power of the slave-owner backed up by that of the colonial [as well as the metropolitan] state.” There was no separating the political and the economic. “Sugar was the business of the state,” a fact with concrete political ramifications: in the case of Britain, the state “legitimated the slave trade” that provided a constant supply of cheap labor to work the sugar fields; it “systematized and codified”—by passing slave codes—freeborn Englishmen’s “right to hold black people as property” in its colonies; it waged wars against other colonial empires to expand territories in the New World and protect its own commercial interests; and its colonists regularly needed its “military and naval support against internal and external enemies” (Hall, Reference Hall2022, pp. 12–15).

Thus, the state buttressed colonial slavery and let it “reproduce itself,” accrue capital for the state and wealthy stakeholders alike, and underwrite a “system of capitalist expropriation of labour.” This system not only “enabled a family such as that of Edward Long to live off the slavery business for six generations,” but also empowered someone like Long to influence public opinion through history-writing and “give life to the overarching signifier … of race, as it articulated with the economy, the law, with culture and politics.” This ideational intervention in “the fraught politics of slavery” would have “a long life”—to this day. Such is “the power of the word” that Long understood so well when he produced The History of Jamaica (Hall, Reference Hall2022, pp. 18–19; see Shyllon, Reference Shyllon2021; Hall, Reference Hall2024).

Long’s case epitomized a mutually enabling relationship between economic (material) and cultural (ideological) factors in the development of racial capitalism. If the racialization of the enslaved reflects the needs of capitalism in a given historical context, this racialization can then become a force of its own. It may join forces with various other factors to engender what Cynthia Moe-Lobeda calls “structural evil.” This refers to “chains that bind us into systemic exploitation of others” as a result of “humanly constructed” factors, including “interrelated power arrangements, ideologies, values, practices, policies, and ways of perceiving reality that span generations and have unintended snowballing consequences” (Moe-Lobeda, Reference Moe-Lobeda2013, pp. 2–3, emphasis added). The highlighted factors point to a form of violence called “cultural violence.” Aspects of culture can be used to legitimize direct violence (“direct cruelty perpetrated by human beings against each other and against other forms of life and nature in general”) or structural violence exemplified by evolving patterns of exploitation. Cultural violence thus provides a “substratum from which the other two [forms of violence] can derive their nutrients”: for instance, “the culture preaches, teaches, admonishes, eggs on, and dulls us into seeing exploitation and/or repression as normal and natural, or into not seeing them (particularly not exploitation) at all” (Galtung, Reference Galtung1990, pp. 294–95, emphasis added; see Moe-Lobeda, Reference Moe-Lobeda2013, pp. 75–7).

In these terms, Kant’s normative silence about colonial slavery might be due to a failure of recognition rooted in his racialization of the “Negro.” This racialization makes best sense when seen as part of the cultural superstructure that arose from the practices of colonial slavery and, in turn, helped to sustain the latter.Footnote ¹¹ Given what we have learned so far, we can expect that, in the eighteenth century, the “Negro” would be portrayed as naturally and uniquely able to serve a global economy that hinged on a steady supply of cheap, strong, and manageable labor. This was how Kant racialized the “Negro” in his writings and lectures from the 1770s onward.

Kant traces “true Negroes” to West Africa (VvRM, 2, 441–42), the epicenter of the transatlantic slave trade. There was a notable shift in how he talked about them over time, from denigrating their mental capacity to delineating their labor capacity. Writing in 1764, Kant linked black skin to low intelligence. The difference between whites and the “Negroes of Africa,” he claimed, must be “just as great with regard to the capacities of mind as it is with respect to color.” Thus, the mere fact that “a Negro carpenter … was completely black from head to foot” sufficed as “a distinct proof that what he said was stupid.” To generalize this association of black skin with stupidity, Kant invoked Hume’s notorious assertion that “among the hundreds of thousands of blacks who have been transported elsewhere from their countries, … not a single one has ever been found who has accomplished something great in art or science or shown any other praiseworthy quality” (BGSE, 2, 253–55).

By the time Kant published his first essay on race (1775, revised in 1777), he had become fixated on the black body with its supposedly unique physical and physiological characteristics.Footnote ¹² He suggested that the hot and humid equatorial climate had given “Negroes” not only their “thick turned-up nose” and “thick lips,” black and oily skin, and “evaporation of the phosphorous acid (of which all Negroes stink),” but also a particular sort of animality.

For Kant, once these features took root through a long adaptation to one’s native climate, they became irreversible and unfailingly hereditary. This was the most controversial but also most significant aspect of Kant’s raciology.

The animal-like physique attributed to “Negroes” purportedly made them more suitable for field labor than Native Americans. Kant saw the latter as a poorly adapted race, whose “natural disposition … betrays a half extinguished life power” due to inadequate acclimation. To support this assertion, he turned to practices of slavery in the Dutch Surinam (recall: this was the site for the horrors of slavery depicted in Voltaire’s Candide). In that sugar colony, Kant claimed, “one makes use of the red slaves (Americans) … only for labors in the house because they are too weak for field labor, for which one uses Negroes”—not due to any shortage of coercive means, but because Native Americans lack power and endurance by nature (VvRM, 2, 437–38). So, Kant elevated the “Negro” above the red race in terms of fitness for labor: the latter race is “too weak for hard labor, too indifferent for industry and incapable of any culture,” wherefore it “ranks still far below even the Negro” (ÜGTP, 8, 176; see Lu-Adler, Reference Lu-Adler2022a). A key difference concerns susceptibility to discipline: as Kant racialized them, Native Americans lack passions, “do not care for anything,” and therefore cannot be incentivized to do anything; by contrast, “Negroes” are full of passions, especially fear of beatings, which makes them trainable for the culture of subjugation ( Bildung der Knechte ) (V-Anth/Mensch, 25, 1187).Footnote ¹³

Kant’s racialization of the “Negro” as simultaneously strong and lazy in the 1770s already planted the seeds for an anti-abolitionist stance, insofar as he thereby suggested that they could only be forced to toil in the sugar fields. This anti-abolitionist stance became even more salient in Kant’s remarks about “Negroes” in the late 1780s and early 1790s, when the abolitionist campaigns began to gain momentum in Europe. When Kant invoked Hume again in his 1792 course on physical geography, he paraphrased Hume as saying that “among the many thousands of Negroes who are gradually being set free, there is no example of anyone who has distinguished himself with particular craft [Geschicklichkeit].” The wording suggests that the formerly enslaved, due to “something essential in the character of the Negro,” could not make any productive use of their newfound liberty, even to cultivate something as basic as a (manual) craft. Kant took this to explain “why no freed Negro works the fields” and why “he prefers to … become a servant” (Dohna mns, 105).

Kant was thereby doubling down on his earlier claim, made in his 1788 essay on race, that freed “Negroes” were not fit to be “farmers or manual laborers.” On his account, “Negroes” lack an inner “drive” to work due to the “far lesser needs” and the ease with which such needs can be satisfied in their motherland; once this laziness has been formed in their native climate, it is “interwoven” with other natural predispositions of their race and becomes as indelible as their black skin (ÜGTP, 8, 172–74). For evidence, Kant turned to James Tobin, a planter in Nevis and then Bristol-based merchant and fervent anti-abolitionist (Small, Reference Small2004). Calling Tobin “a knowledgeable man,” Kant invoked part of his response to the abolitionist Reverend James Ramsay’s “wish to use all Negro slaves as free laborers”:

There were material reasons behind why the freed Blacks Tobin saw in England were reduced to degrading positions of servitude. The majority of the Black Poor, as they were called, were former slaves. Their number surged in the mid-1780s as a consequence of the American Revolutionary War (1775–83): many Black Loyalists, enslaved men who helped the Loyalists during the war because they were promised freedom, were brought to London as freedmen. They were only nominally free, however. Impoverished and receiving no financial assistance from the government (sometimes denied such assistance because of their race), they had no option but to take whatever menial urban jobs they could get (Lu-Adler, Reference Lu-Adler2025b, 214n.18). The only explanation for this phenomenon Kant could think of, however, was what he already believed about “Negroes”: they lack “an immediate drive to activity (especially to the sustained activity that one calls industry)” and they “do not bring any more of this impetus into other climates and pass it on to their offspring than was needed for their preservation in their old motherland and had been received from nature” (ÜGTP, 8:174n).

I describe this view as anti-abolitionist (a political stance), not pro-slavery (a moral stance), because my main concern in this paper is not what Kant the moral philosopher might say about slavery (Lu-Adler, Reference Lu-Adler2022a). Suppose he thought that colonial slavery, considered in itself, was morally wrong. Most Enlightenment thinkers were receptive to such a basic moral judgment. And Kant certainly had the language to articulate it if he wanted to (he never did). The harder question, however, is to figure out what to do about colonial slavery as a structurally entrenched, legally sanctioned institution that was pivotal to a complex global economy and intricately tied with the wealth and, with it, the political power of a nation. I shall pose this question to Kant the political philosopher.

4. Postlude: Kant’s “Moral Politician” and the Prospect of a Radical Kantian Liberalism

I began this article by foregrounding Kant’s normative silence about whether colonial slavery, as an institution, violated the rights of the enslaved humans. I suspected that this silence was a considered choice, not a careless oversight (as if Kant merely forgot to add that colonial slavery was unjust when he mentioned it across so many contexts, including in the Doctrine of Right). To substantiate this suspicion, I highlighted a feature of colonial slavery from the perspective of political economy: it was vital to the prosperity of many European states, so much so that it was supported by the legislative, administrative, and military powers of those states and largely condoned by the public (Section 2). If the massive enslavement of Black Africans thus began as a perceived economic necessity (to solve the labor problem in Europe’s New World colonies), their subsequent racialization as physically robust but lazy and slavish “Negroes” would provide a potent justification for their (continued) enslavement by naturalizing and normalizing it. Kant channeled this racial ideology by depicting the “Negro” as uniquely suited for grueling, coerced labor due to certain congenital and immutable traits (Section 3).

All the while, Kant might second Burke’s warning that slaves should not be crushed by the iron rod with which they were disciplined, a warning that resonated with his belated misgivings about the excessive brutality of the slavery practiced on the Sugar Islands. He correctly observed that, as a matter of fact, “Negro slaves” functioned as money in the transatlantic trade system, their number measured a nation’s wealth, and the business of colonial slavery was therefore inextricably tied with a competitive or even openly bellicose intra-European politics. Although describing these historical facts is not the same as endorsing them, Kant’s normative silence about the institutionalized practices of enslaving and commodifying humans is still troubling and worth interrogating (Section 1).

Kant’s claims and silences about slavery and the enslaved “Negroes,” as well as the fact that he indirectly benefited from their labor, give us a window into the contours of racial capitalism. I used this concept to highlight the following: the enslavement, commodification, and exploitation of “Negroes” was foundational to the economic development of Europe (and the newly independent United States) well into the nineteenth century; the relevant state power played an active role in legitimizing and protecting those practices; individual European citizens helped to enact and sustain the complex economic system that built on colonial slavery through actions that ranged from owning or trading slaves to investing in related businesses or simply consuming goods derived from slave labor (especially sugar); meanwhile, “Negroes” came to be racialized in such a way that their (continued) enslavement appeared natural; the resulting racial ideology would then get lodged in a cultural superstructure to influence subsequent historical developments (even after the abolition). It was against this backdrop that Kant racialized “Negroes” as exceptionally tough, servile, and lazy, refrained from condemning their enslavement as unjust, and occasionally indicated anti-abolitionist sympathies (Section 3).

This analysis poses a philosophical challenge to anyone who takes for granted that “Kant’s theory is fortunately stronger than his prejudices” and that we can set aside his racism as a mere personal prejudice to “focus” on his theory (Louden, Reference Louden2000, p. 105). The challenge also extends to those who, for all their unflinching critique of Kant’s racism, nevertheless hope that Kantian liberalism can somehow be “deracialized,” radicalized through a “synthesis” with Black radical theories, and thereby transformed into a Black radical Kantianism. Specifically, the hope is to rethink “key principles and ideals of Kant’s ethico-political thought”—such as “the respect for the rights of individual persons, the ideal of the Rechtsstaat … and the vision of a global cosmopolitan order of equals”—“in the light of a modernity structured by racial domination” (Mills, Reference Mills2018, pp. 2–3).

A major challenge to this hopeful vision concerns the primacy of the state in Kant’s political philosophy and his unwavering defense of the state so long as it is nominally law-governed, regardless of how unjust or oppressive the laws are. According to Kant’s philosophy of history, if humanity is destined to perfect itself (morally) at some point, this can be accomplished “only in the species, but not in the individual” (IaG, 8, 18) and only in a law-governed civil condition (IaG, 8, 25–6). As a theory of this condition, Kant’s political philosophy regards humanity “not as [a sum of] individuals … but rather as divided into nations and states” (SF, 7, 84, emphasis added). This approach can have profound implications for colonial slavery (or any unjust institution that is backed up by the state). If everyone has an “innate” right to freedom “by nature” or “by virtue of his humanity” (MS, 6, 237), it can be rightfully secured or enjoyed only in a civil state, under an authority with the power to enact public laws (MS, 6, 242, 255, 305–06). That is, individuals have a rightful claim against each other only as citizens of a state, in virtue of which they have civil personality. Colonial slaves lacked such personality, being legally codified as mere things. They were civil non-beings in the eye of the state and, as such, had no rightful claims against those who enslaved, traded, or exploited them at will (Lu-Adler, Reference Lu-Adler2025a).

Assume, for the sake of argument, that a Kantian moralist would unequivocally condemn colonial slavery. As I have suggested, however, once colonial slavery was set in motion and became a legally sanctioned institution protected by sovereigns and intertwined with each nation’s own political-economic interest, its fate was no longer just a moral question. It became a thorny political problem above all else. So, let us summon Kant’s “moral politician” and see how he might address it. Such a politician, while recognizing that the defects in the laws of a state are not to be “altered at once and violently,” will “at least take to heart the maxim that such an alteration is necessary” and feel duty-bound to be concerned about how the relevant laws “can be improved as soon as possible and brought into conformity with natural right.” In short, he must unite moral conscience with political sagacity. In particular, if he clearly recognizes the current social order as unjust, he is nevertheless “permitted to postpone putting [a just condition] into effect until a more favorable time” (ZeF, 8, 372–73). In principle, there are “permissive laws of reason that allow a situation of public right afflicted with injustice to continue until everything has either of itself become ripe for a complete overthrow or has been made almost ripe by peaceful means.” This latitude has again to do with the primacy of the state in Kant’s political philosophy. Having an unjust state is better than having no state: “some rightful constitution or other, even if it is only to a small degree in conformity with right, is better than none at all, which latter fate (anarchy) a premature reform would meet with” (ZeF, 8, 373n).Footnote ¹⁴

What would this Kantian moral politician say about colonial slavery, given how deeply a global political-economic structure was entangled with it (as I tried to show)? Here is the most likely answer: colonial slavery should certainly be abolished, but let us ensure a gradual, judiciously executed process of abolition with an eye to a rightful political order both within each of the affected (European) states and among them.

Indeed, we can find such a conciliatory answer in Condorcet’s Réflexions sur l’esclavage des Nègres (Condorcet, Reference Condorcet1781). As Luis Sala-Molins puts it in a chapter aptly entitled “Condorcet, ‘Lamenting’,” the Réflexions begins with a searing moral indictment of colonial slavery only to descend “from such perceptive heights to the appalling rigor of ignoble comprises” (Sala-Molins, Reference Sala-Molins and Conteh-Morgan.2006, p. 17). In the name of “prudence” and “public order,” Condorcet envisioned that colonial slavery would gradually phase out after seventy years, with an economy safely weaned off of slave labor and a population of emancipated “Negroes” sufficiently trained to serve as virtuous and productive free labor in the new economy (Condorcet, Reference Condorcet1781, pp. 13–14, pp. 31–52). Condorcet’s justification for the delay accords with Kant’s permissive laws: the legislator “owes it to the society … not to make laws, even the most just, if he presumes that they will bring trouble, before having secured either the means of preventing troubles or the force necessary to punish those who cause them”; above all, he must ensure that the public will have no fear either from disturbances by the newly emancipated or from “the fury of masters wounded in … greed and pride—for a man accustomed to seeing himself surrounded by slaves is not consoled by having mere inferiors” (Condorcet, Reference Condorcet1781, pp. 17–18).

Such was the political vision of even “the most generous” of all philosophes (Sala-Molins, Reference Sala-Molins and Conteh-Morgan.2006, p. 17). It not only left the existing structure of domination intact and unquestioned, but also reinforced demeaning assumptions about “Negroes.” Unlike Kant, Condorcet did not claim that “Negroes” were intellectually or morally inferior by nature. He nevertheless espoused what Julia Jorati (Reference Jorati2025) calls the “effects-of-slavery view” of their alleged inferiority. This view limited Condorcet’s political imagination about the place of freed “Negroes” in society: they were to be passively integrated into the polity as obedient, productive, and nominally free labor to maintain the economy that was founded on their people’s slave labor, and the state must keep a watchful eye on them lest they disturb public order. Could Kant’s “moral politician” imagine anything better for the formerly enslaved?

I ask this question not just because Kant had a more thoroughly racist view of the “Negro.” Rather, my main concern is that, as Judith Shklar puts it, Kant’s “normal model of justice” may not be “adequate to the task of controlling [injustice] in practice” or even “understanding it in theory,” due to its “complacent view of injustice and its confidence in the ability of the institutions that it underwrites really to cope with iniquity” (Shklar, Reference Shklar1990, pp. 18–19). As I have tried to capture with the notion of racial capitalism, state power played a pivotal role in upholding colonial slavery and serving the interests of the economic elites (even after the abolition). That is why historian Howard Zinn concluded from his study of the abolition of slavery in the United States that “liberation from the top would go only so far as the interests of the dominant groups permitted” (Zinn, Reference Zinn1995, p. 167). Zinn came to realize that, in “a society of contending interests” where the state is “on the side of the rich and powerful” and therefore something is “rotten at the root,” one can no longer be a “liberal” betting on the “self-correcting character” of the existing institutions; rather, one has to be a “radical” fighting, in solidarity with others from the bottom up, for “an uprooting of the old order, the introduction of a new kind of society” (Zinn, Reference Zinn1994, pp. 172–73).

To connect this contrast between the “liberal” and the “radical” with Charles Mills’s idea of Black radical Kantianism mentioned above, I ask: Is it really a viable project to make Kantian liberalism “radical”?Footnote ¹⁵ I ask this question in a world that still struggles to reckon with—or even to understand—historically sedimented political-economic structures of exploitation and the concomitant cultural and material legacies. I take no answer for granted. Nonetheless, I hope that my analysis in this paper has made the question worthwhile.Footnote ¹⁶