An Essay on the Slavery and Commerce of the Human Species, Particularly the African Translated from a Latin Dissertation, Which Was Honoured with the First Prize in the University of Cambridge, for the Year 1785, with Additions

Thomas Clarkson's "An Essay on the Slavery and Commerce of the Human Species" is a thorough and sobering examination of the African slave trade and the institution of slavery as it existed in the late 18th century. Originally a prize-winning Latin dissertation, this English translation with additions offers a structured exploration of slavery's history, its moral and legal implications, and the lived experiences of enslaved Africans.

The essay begins by tracing the ancient roots of involuntary slavery, distinguishing it from voluntary servitude. It highlights how slavery was widespread in antiquity—among Greeks, Romans, and various barbarous nations—often linked to prisoners of war, piracy, or punishment. Clarkson emphasizes that slaves were treated as property, which dehumanized them and justified cruelty. He refutes the idea that slaves were naturally inferior, citing examples of slaves who displayed remarkable genius and virtue, such as Æsop and Epictetus.

Clarkson then turns to the revival of slavery in Africa by European powers, particularly the Portuguese, who initiated a brutal commerce involving treaties with African chiefs. These chiefs, corrupted by European goods and weapons, waged wars to capture slaves, often inventing crimes to justify enslavement. The essay identifies four classes of involuntary slaves in Africa: convicts, prisoners of war, those seized by princes, and kidnapped individuals. The author condemns the complicity of African rulers and the cruelty of European merchants and colonists, such as the Dutch at the Cape, who hunted indigenous peoples like game.

Central to the essay is a moral and legal critique of slavery. Clarkson argues that all men are born free, owning their bodies and minds, and cannot justly be made slaves without consent. He rejects the notion that liberty can be bought or sold, and condemns the treatment of humans as property, which violates natural law, reason, and divine law. The essay scrutinizes the justifications offered by slave traders and owners, exposing contradictions and falsehoods—such as claims that slavery benefits Africans or that they are naturally suited for servitude.

A vivid and harrowing narrative describes the capture, branding, and brutal treatment of slaves in Africa, their crowded and deadly passage across the Atlantic, and their sale and harsh labor conditions in the colonies. Clarkson presents documented evidence of cruelty, including mutilations, torture, and even murder for insurance claims. He highlights the devastating demographic impact of slavery, noting that the descendants of hundreds of thousands of imported slaves numbered far fewer due to the harsh conditions.

The essay also challenges racial prejudices underpinning slavery. Clarkson refutes claims of African inferiority based on intellect or skin color, arguing instead that environmental factors and oppression explain perceived differences. He presents examples of African literary and intellectual achievements, such as the poetry of Phillis Wheatley and the writings of Ignatius Sancho, to demonstrate equality of capacity. Biblical and scientific arguments are used to dismantle the idea of Africans as a separate or cursed species.

Throughout, Clarkson appeals to Christian principles, natural rights, and reason to condemn slavery as impious and unjust. He underscores the incompatibility of slavery with the doctrine of brotherly love and the social contract that governments must uphold. The essay concludes with a call to recognize the humanity and liberty of all people, exposing the slave trade as a crime against law, equity, and conscience.

This work is both a historical account and a passionate plea for justice, combining scholarly analysis with vivid human stories. It challenges readers to confront the brutal realities of slavery and question the moral and legal foundations of a system that treated millions as property.