When he wrote "Letter from Birmingham Jail" Martin Luther King was under arrest for promoting a peaceful protest in favor of civil rights. Although he used his letter to reinforce the importance of the black struggle for rights and how the protests were the result of a society full of injustice, King's main purpose was to respond and criticize the position of renowned Christian pastors in condemning the movements that blacks, led by King, were establishing.
King, being an expert speaker, was able to easily write his caste with a wide use of all the devices of rhetoric. He used logos with mastery when he said that black citizens were only responding to the injustices to which they were subjected and that if society were just, this type of protest would not be necessary. He used Ethos when he protested respectfully and criticized the position of his opponents in a cultured and noble way. Last but not least, he used pathos, when he evoked the emotions of his supporters when he affirmed that his imprisonment was part of a bigger and more powerful project, strengthening his message and establishing him as a great leader.
