The contrast clue for sorrow in this sentence is felt. behind. happiness. publicly.

cugoano was one the first emerging forces to abolish slavery in the 18th century. the belief that cugoano states on "people who oppose slavery deserve praise" refers to those who like him supported the thoughts of abolishing slavery, thus making improvements in the society and civilization of those days and in the future.

his belief "who are worthy of universal approbation" is supported by "and as we hear tell of the kings of europe having abolished the infernal invention of bloody tribunal of the inquisition, and the emperor and others making some grand reformations for the happiness and good of their subjects; it is to be exalted and liberal principles will lead them onto greater " those leaders who have agreed on following the natural right of freedom and equality for all were so valuable in a global scale.

he eats poisonous worms that eventually kill him.