Romans 2:15 declares that even those without the written law “show that the work of the law is written on their hearts, while their conscience also bears witness, and their conflicting thoughts accuse or even excuse them.”¹ Paul describes an interior tribunal. Human beings may lack Scripture, but they do not lack moral awareness. Conscience does not invent moral law; it testifies to it.

The Atlantic slave trade presents one of the most severe historical tests of this claim. The men who captained, staffed, financed, and defended the trade were not morally unexposed. The conditions aboard slave ships were not abstract. They were sensory, immediate, and inescapable. If Romans 2:15 is true, then those who participated were not ignorant of evil. They were internally divided.

The slave trade was sustained not by the absence of conscience, but by its suppression.

The Middle Passage: A Sensory Indictment

Enslaved Africans transported across the Atlantic were confined in holds often less than five feet high, shackled in rows, packed tightly to maximize profit.² The 1788 abolitionist diagram of the slave ship Brookes visually displayed the systematic compression of human bodies into cargo formation.³

Mortality rates during the Middle Passage averaged roughly 10–20 percent, varying by decade and voyage.⁴ Dysentery, dehydration, smallpox, violence, and suicide were frequent realities. Surgeons’ logs and parliamentary testimony describe the stench of excrement, the groans of the sick, and bodies cast overboard.⁵

These were not hidden crimes. Captains, surgeons, and sailors saw the chains cutting into flesh. They heard the cries of the dying. They smelled the rot of overcrowded decks.

Romans 2:15 suggests that such exposure did not occur in moral neutrality. Conscience bore witness.

Natural Law and the Universality of Moral Knowledge

The Christian natural law tradition affirms that certain moral truths are universally accessible because they are inscribed in human nature itself.

Thomas Aquinas argued that the first principle of practical reason — “good is to be done and pursued, and evil avoided” — is known to all.⁶ Conscience is the application of that moral knowledge to particular acts. Error arises not because the basic principle is unknown, but because reasoning is distorted in its application.

If Aquinas is correct, then the wrongness of chaining, degrading, and commodifying human beings did not require special revelation. It required only the faithful application of universally accessible moral knowledge.

The theological defenses of slavery therefore do not demonstrate ignorance of moral law. They reveal moral reasoning subordinated to economic interest.

Reformed Theology and the Inner Tribunal

Reformed theology likewise affirms the universality of conscience.

John Calvin described conscience as “a certain mean between God and man,” an inner tribunal that anticipates divine judgment.⁷ Even those who deny God cannot fully silence this internal judge.

The slave trade illustrates Calvin’s insight. Historical testimony reveals participants describing unease, disturbance, and later shame. The internal tribunal was not absent; it was resisted.

Reformed theology also recognizes the noetic effects of sin. Human beings suppress truth in unrighteousness (Romans 1:18). The problem is not lack of light, but resistance to it.

The Seared Conscience

Scripture also warns that conscience can be hardened.

First Timothy 4:2 speaks of those “whose consciences are seared.” The imagery is surgical: cauterized flesh loses sensitivity. Moral perception can become dulled through repeated violation.

The Atlantic slave system required such hardening. Repeated exposure to suffering demanded psychological numbing. To maintain order, traders shouted down cries. To preserve profit, they reclassified people as cargo. To silence inner disturbance, they rehearsed racial and theological rationalizations.

Conscience does not disappear. It can, however, be disciplined into silence.

Conflicting Thoughts: Accusation and Excuse

The historical record reveals precisely the conflict Paul describes.

John Newton (1725–1807)

Newton experienced a religious awakening during a violent storm in March 1748. Yet he continued in the slave trade until illness ended his seafaring career in 1754. Only in 1788 — more than three decades later — did he publish Thoughts Upon the African Slave Trade, confessing:

“I hope it will always be a subject of humiliating reflection to me, that I was once an active instrument in a business at which my heart now shudders.”⁸

“I hope it will always be a subject of humiliating reflection to me, that I was once an active instrument in a business at which my heart now shudders.”⁸

Newton’s abolitionist confession came decades after his participation. His life illustrates the slow moral awakening conscience sometimes requires. His later hymn, “Amazing Grace,” gains depth when read against this history: “I once was blind, but now I see” was not metaphor detached from material reality.

James Field Stanfield (1749–1824)

Stanfield, a former slave ship surgeon, described being haunted by the horrors he witnessed.⁹ His testimony reveals the psychological residue of suppressed conscience.

Thomas Clarkson (1760–1846)

Clarkson recorded interviews with sailors who confessed guilt “with tears in their eyes,” admitting that no one could long remain in the trade and preserve his humanity.¹⁰

Here the interior courtroom of Romans 2:15 is visible: moral knowledge accusing even as economic survival excused.

Olaudah Equiano (1745–1797)

Equiano observed that some captains, when brought to reflection, were “much troubled in mind,” though interest too often prevailed.¹¹

The law written on the heart spoke. Profit answered louder.

Moral Unease Among the Powerful

George Washington (1732–1799)

In 1786 Washington wrote that no one wished more sincerely than he to see slavery abolished.¹² Yet he did not dismantle the system during his lifetime except through provisions in his will.

His correspondence reveals moral discomfort that did not translate into immediate structural dismantling. Thoughts accused; social and economic entanglements excused.

Theology, Profit, and Suppression

The Atlantic slave trade required doctrinal innovation — racialization of servitude, theological separation of soul from body, reinterpretation of biblical texts. But beneath those constructions, conscience remained operative.

Natural law testified.Reformed theology affirmed an internal tribunal.Scripture warned of searing.

The system endured not because moral knowledge was absent, but because it was subordinated.

Romans 2:15 does not promise obedience. It asserts awareness.

The holds of the slave ships were not merely economic spaces. They were theaters of moral crisis. The sight, sound, and smell of the Middle Passage were sufficient to awaken the law already written on the heart.

Some hardened themselves.Some wept.Some repented decades later.

The tragedy illuminated by Romans 2:15 is not that they did not know.

It is that they knew — and continued.

Marcus Rediker, The Slave Ship: A Human History (New York: Viking, 2007).

Marcus Rediker, The Slave Ship: A Human History (New York: Viking, 2007).

British Parliament, “Description of a Slave Ship (Brookes),” 1788.

British Parliament, “Description of a Slave Ship (Brookes),” 1788.

David Eltis and David Richardson, Atlas of the Transatlantic Slave Trade (New Haven: Yale University Press, 2010).

David Eltis and David Richardson, Atlas of the Transatlantic Slave Trade (New Haven: Yale University Press, 2010).

Stephanie E. Smallwood, Saltwater Slavery (Cambridge: Harvard University Press, 2007).

Stephanie E. Smallwood, Saltwater Slavery (Cambridge: Harvard University Press, 2007).

Thomas Aquinas, Summa Theologiae, I–II, q. 94, a. 2.

Thomas Aquinas, Summa Theologiae, I–II, q. 94, a. 2.

John Calvin, Institutes of the Christian Religion, III.xix.15.

John Calvin, Institutes of the Christian Religion, III.xix.15.

John Newton, Thoughts Upon the African Slave Trade (London, 1788).

John Newton, Thoughts Upon the African Slave Trade (London, 1788).

James Field Stanfield, Observations on a Guinea Voyage (London, 1788).

James Field Stanfield, Observations on a Guinea Voyage (London, 1788).

Thomas Clarkson, Essay on the Slavery and Commerce of the Human Species (London, 1786).

Thomas Clarkson, Essay on the Slavery and Commerce of the Human Species (London, 1786).

Olaudah Equiano, The Interesting Narrative (London, 1789).

Olaudah Equiano, The Interesting Narrative (London, 1789).

George Washington to Robert Morris, April 12, 1786.

George Washington to Robert Morris, April 12, 1786.

© The Times of Israel (Blogs)