Clarkson (1760–1846), along with Wilberforce, was one of the most important agitators against the trade in slaves in Britain. The ‘moral Steam-Engine, or the Giant with one idea’ as Coleridge called him, first became interested in the slave trade after graduating from St John’s College, Cambridge in 1783 when he won the members’ prize for the Latin essay. The subject of the competition of 1785 was ‘anne liceat invitos in servitum dare?’ or whether it was lawful to make men slaves against their will. Clarkson read the American Quaker Anthony Benezet’s Some Historical Account of Guinea (1771) and Ramsay’s Essay. The subject of his essay took over the young Clarkson and he determined to further research the subject and translate and publish the work. It was published as An Essay on the Slavery and Commerce of the Human Species by James Phillips, the publisher of Ramsay’s Essay. Phillips introduced Clarkson to the prominent British opponents of slavery. Abandoning his plans to enter the Church (he had already been ordained as a deacon) Clarkson decided to devote himself to the cause. In 1787 he became one of the founder members of the Committee for Effecting the Abolition of the Slave Trade. Clarkson spent the autumn of 1787 in the hazardous task of collecting reliable first-hand information against the trade, interviewing sailors in Bristol and Liverpool and scouring the country for creditable witnesses to provide testimony against the trade. Drawing attention to the appalling conditions of the trade and the high level of mortality among those seamen engaged in it, Clarkson presented the abolitionist case to the Committee of the Privy Council, set up in 1788 to investigate the trade. Exhausted by his efforts Clarkson retired from the struggle in 1794, returning to his duty on the Committee in 1805. After the passage of the Abolition Bill in 1808, Clarkson tirelessly campaigned for the international abolition of the trade and the end of slavery as an institution, becoming, along with Wilberforce, a vice-president of the Anti-Slavery Society formed in 1823. Clarkson published many tracts against slavery and the slave trade, the most significant being A 38Summary View of the Slave-Trade and of the Probable Consequences of its Abolition (1788), An Essay on the Impolicy of the African Slave Trade (1788), An Essay on the Comparative Efficiency of Regulation or Abolition as applied to the Slave Trade (1789), Letters on the Slave Trade, and the State of the natives ... in Africa (1789). He was also responsible for the important Abstract of the Evidence Delivered before a Select Committee of the House of Commons (1791) of which over 1,500 copies were printed in 1792. Clarkson’s The History of the Rise, Progress and Accomplishment of the Abolition of the African Slave-Trade by the British Parliament (1808) was the first substantial account of the struggle. The extract included here (taken from the second edition, 1788) is the third part of Clarkson’s prize-winning essay which describes the conditions of slavery in the European colonies.