In general, what struck me most about Martin Luther King’s letter was how humble and level-headed he came across the entire time (not what I would normally expect from someone imprisoned for reasons that are considered unjust).
From the very beginning, MLK uses eunoia: “But since I feel that you are men of genuine good will and that your criticisms are sincerely set forth, I want to try to answer your statement in what I hope will be patient and reasonable terms.” He is showing his audience more respect than they gave him, something that could sway their thinking.
MLK uses religious allusions to create a metaphor for his own actions and reasoning: ” Just as the prophets of the eighth century B.C. left their villages and carried their “thus saith the Lord” far beyond the boundaries of their home towns, and just as the Apostle Paul left his village of Tarsus and carried the gospel of Jesus Christ to the far corners of the Greco Roman world, so am I compelled to carry the gospel of freedom beyond my own home town. Like Paul, I must constantly respond to the Macedonian call for aid.” This would most likely show a similarity between MLK’s views and the views of the clergymen, as they are all Christian and familiar with biblical references.
MLK uses similes/analogies to reinforce points: “The nations of Asia and Africa are moving with jetlike speed toward gaining political independence, but we still creep at horse and buggy pace toward gaining a cup of coffee at a lunch counter.” This really puts things into perspective and shows a scale of change that is not proportional.
Here is an example of parallelism: “One has not only a legal but a moral responsibility to obey just laws. Conversely, one has a moral responsibility to disobey unjust laws.” This is helpful in showing the similar structures in societal laws, but the inherent differences between what is morally correct or incorrect. (Another example: “Any law that uplifts human personality is just. Any law that degrades human personality is unjust.”)
MLK uses a Toulmin-style argument while presenting these logical facts and conclusions: “A law is unjust if it is inflicted on a minority that, as a result of being denied the right to vote, had no part in enacting or devising the law. Who can say that the legislature of Alabama which set up that state’s segregation laws was democratically elected? Throughout Alabama all sorts of devious methods are used to prevent Negroes from becoming registered voters, and there are some counties in which, even though Negroes constitute a majority of the population, not a single Negro is registered. Can any law enacted under such circumstances be considered democratically structured?” This is extremely important as it portrays the government (highest ruling power in the South) as what is ultimately unjust and needs to be changed. This helps justify more of the civil disobedience and nonviolent protests by African Americans in Birmingham.