Agood listener must decide between
list the four areas where evaluating the evidence for what is said becomes necessary.

bias of the speaker, subjective evidence( leave out the emotion ), qualifications of the speaker (education, training, experience), and your need to discern facts versus personal opinions.

here's a quizlet with more info!

the answer is slaves

douglas was a slave who turned into a statesman and he refused to celebrate the 4th of july until all slaves were emancipated or set free.