Behn 's story was adapted for the stage by Irish playwright Thomas Southerne , who stressed its sentimental aspects , and as time went on it came to be seen as addressing the issues of slavery and colonialism , remaining very popular throughout the Eighteenth Century . Behn 's story was adapted for the stage by Irish playwright Thomas Southerne , who stressed its sentimental aspects , and as time went on , it came to be seen as addressing the issues of slavery and colonialism , remaining very popular throughout the 18th century .