3. In the fourth paragraph, the author mentions what he "gained from the dialogue" and what he "got from Sheridan" (lines 29-30) primarily to
- propose the denunciation of slavery and promote human rights
- defend his ideals of social justice and influence others to act
- challenge the moral obligations of the educated and validate his conscience
- highlight the plight of enslaved people and influence the morality of society
- illustrate his developing arguments against slavery and validate his beliefs