The pamphlet condemns the transatlantic slave trade on moral, legal, and practical grounds, arguing it contradicts divine and civil law and harms both European and African societies. Written in the plain form of a sermon, it surveys ethical objections, economic and political disadvantages, and the advantages abolition would bring to Britain, its colonies, and Africa, then proposes measures to place commerce with Africa on a just and lawful footing. The author appeals to readers' sense of liberty and humanity and urges both popular conviction and legislative action to end the inhuman traffic.