Thematically the work touches on values typical in Behn’s fiction, including the right of women to select their spouses and the paramount value of romantic love. The two dominant themes, however, are opposition to slavery and the celebration of primitivism. In terms of modern understanding, both themes must be severely qualified. The celebration of primitive tribal life is calculated to appeal to a contemporaneous audience fascinated with the New World. Although she develops the theme in both Africa and Suriname, her most extensive depiction of primitive nobility relates to the New World. The indigenous peoples of Suriname demonstrate the superiority of the primitive over the more complex European civilization. A people guided by modesty, simplicity, and innocence, they have no concept of sin, no natural sense of guilt, no words for falsehood and deception. They have no need of complex laws to govern their behavior, but are guided by a natural sense of right and wrong. Admirably adjusted to their environment, they live a life of basic virtue and do little harm. Behn cautions that European mores and religion could only harm their idyllic lives.
As for its antislavery message, the approach is less clear. Slavery is depicted as endemic in Africa, though a clear evil. Even Oroonoko and his grandfather sell their low-ranking captives into slavery, though Oroonoko attempts to protect his noble captives. Those who are enslaved think first and foremost of regaining their liberty and attempt this whenever an opportunity arises. The narrative exposes the violence done to family units under slavery. Europeans involved in the slave trade are portrayed as treacherous and evil, yet once the slaves have reached plantations, not all masters are unkind to them. The supervisor of Oroonoko’s plantation, Trefrey, treats him as an equal and attempts to intercede on his behalf and to offer protection. By portraying Oroonoko as a noble savage, unjustly and treacherously enslaved, Behn contributed to the growing antislavery sentiment in England. The story of Oroonoko gained further public exposure after the dramatist Thomas Southerne used the romance as the source for his popular drama Oroonoko (1695).