Addressed to the legislators of the Spanish government, the introduction to this abolitionist pamphlet describes slavery as a public issue and as a "burden weighing heavily on the conscience of all Spanish people" (vi). It was published in order to call Spanish public attention to two recent pamphlets published in France on the Spanish revolution and colonial slavery, by the Cuban politician José Saco and the French abolitionist Augustin Cochin. Labra criticises Saco's pamphlet for its cautious gradualism, praising instead Cochin's more radical, immediatist approach.