King's primary motive in the letter is to assuage the white clergy's fears and anxieties, which requires countering their dismissiveness with an emotional appeal that in fact there are truly dangerous and antisocial movements to be concerned about. To do so, he uses pathos to persuade the city’s spiritual leaders that he and his followers should be regarded not as “rabble rousers” and “outside agitators. In an appeal to principle and common purpose that is a good example of ethos, King reminds his audience the they are allies in a long, sacred tradition of speaking truth to power.
Correspondingly, King uses an appeal based in logos to support his argument with facts and other examples from a variety of religious, philosophical, and historical contexts that have unique significance for his audience of white Catholics, Protestants like King, and Jewish leaders. King wanted the Birmingham clergy to understand that the movement for civil rights and an end to segregation were universal human causes with roots in America’s most basic principles, which were themselves founded in a shared religious and philosophical heritage. According to King, this common legal, political and religious heritage distinguishes between laws that are just and laws that are unjust and dictates that unjust laws should be resisted just as just laws should be obeyed, a claim based in reason and logic.
Another example of an ethical appeal is King's suggesting that By not standing up to challenge these openly racist policies and instead choosing to avoid conflict and maintain business as usual, the white clergy was giving their support for those policies even if not in open agreement with them. Their criticism of King and his followers that prompted this letter indicates where the white clergy’s values and priorities were. By questioning the legitimacy of King’s presence in Birmingham and remaining silent and neutral on the matter of segregation’s immorality and injustice, the ministers, priests, and rabbis were not only turning their backs on their religious history, but also on their nation’s founding principles.