The ability to write a powerful persuasive piece results from total awareness of available rhetorical devices. Martin Luther King, Jr. demonstrates that he can effectively wield the sword of rhetoric in his famous Letter from Birmingham Jail. While imprisoned in Birmingham after leading a series of non-violent civil rights marches, King read a letter in the city's newspaper that the city clergymen had written to him. The piece was entitled "A Call for Unity," and it suggested that King cease his protesting and wait to peacefully negotiate rights for African-Americans. Immediately, King began to draft a response piece on the very newspaper he was reading, a piece that would outline for critics why his actions of civil disobedience were essential and why it was necessary that more people, particularly white moderates, should be motivated to actively campaign for African-American rights. This piece, Letter from Birmingham Jail, showcases King's attention to distance, sentence structure, and overall tone as he balances the three appeals to prove his point.
Varied sentence structures allow King to build his argument in ways that appeal to both logos and pathos. Particularly notable is his usage of sharp, succinct balanced sentences, which serve a dual purpose as extremely emphatic statements and extremely quotable statements. These balanced sentences often appear at the very end of a section of concrete explanation, serving as a short summary of King's point. Near the beginning of the essay, King confirms that he is "cognizant of the interrelatedness of all communities and states," using this as a reason why he felt it necessary to travel to Birmingham for a protest. He ends this thought with a concise balanced sentence: "Injustice anywhere is a threat to justice everywhere." Because strong logical reasoning reinforces these sentences, they carry considerable force and help the reader fully absorb his point. This also contributes to King's ethos, making him seem very knowledgeable and therefore very credible and persuasive.
While King's logic is integral to the success of his piece, he does not lose sight of the value of pathos. One of the highlights of King's essay is a lengthy paragraph on the third page concerning the way African-Americans have waited for their rights. The majority of the paragraph is a drawn-out periodic sentence which lays out struggles that African-Americans face, including the image of a six-year-old girl with "ominous clouds of inferiority beginning to form in her little mental sky" because of segregation, and the sight of "twenty million Negro brothers smothering in an airtight cage of poverty in the midst of an affluent society." The tension of the sentence builds and builds until the final clincher statement -- "then you will understand why we find it difficult to wait." The African-Americans waited and waited for the day when they would finally be granted Constitutional rights; yet, that day never came, thus locking them into an endless cycle of suffering. This periodic sentence translates a brief version of this cycle into writing. He forces readers themselves to wait uncomfortably for the sentence to draw to a close, but once it does, King's ending statement becomes all the more powerful. The sentence generates a visceral emotional response as an effective appeal to the audience's emotion.
The distance created by King's tone closes the gap between him and his audience, and in so doing adds to the persuasive nature of his piece. Since this piece is, first and foremost, a letter, King realizes that he must directly address his initial audience of a few Birmingham clergymen. He extends polite compliments to the clergymen, referring to them as "men of genuine good will" and acknowledging that their criticisms were likely "sincerely set forth." King chooses to use very polite, formal diction when addressing them, since he realizes that he must persuade the clergymen to think highly of him if he wants them to even attempt to understand his points. He engages directly with the clergymen, addressing specific pieces of their argument to show that he has taken their ideas into deep consideration. Yet, King understands that the piece must work both ways, and so he uses rhetorical questions to provoke the clergymen to consider his own ideas on the subject. When discussing the way to distinguish between just and unjust laws, King walks the clergymen through a variety of different concrete examples, quoting philosophers such as Buber and Tillich and explaining how "any law that degrades human personality is unjust."
After laying out his evidence, King directly asks the reader, "is not segregation an existential expression of man's tragic separation, his awful estrangement, his terrible sinfulness?" This powerful inquiry forces his audience to confront their preconceived notions about just and unjust. King likely intended that this rhetorical question cause the clergymen to step away from their own ideas as they engaged with his own.
King's dramatic shift in tone near the end of the letter is the final indicator of his ability to completely understand his audience. While the first half of the essay features polite diction as King responds to the clergymen's claims, the second half of the letter becomes more accusatory as he begins to directly address what he believes to be his audience's shortcomings. In particular, King discusses his "grave disappointment" with white moderates, the ones who tell the African-Americans to merely wait for the government to grant them their rights. King retaliates that these people live "by a mythical concept of time" and have "shallow understanding" of the true issue at hand, cinching his argument with the claim, "lukewarm acceptance is much more bewildering than outright rejection." Though the clergymen are calling for negotiation, they are also implying that the African-Americans should passively wait to be granted their rights, which places them in the white moderate category that King so vehemently critiques. Since King initially uses polite diction to persuade the clergymen to carefully examine his point of view, he realizes he now has some freedom to begin edging towards definite critiques of their actions. King goes on to voice his disappointment with the church itself, calling it an "archdefender of the status quo" -- a body who protects the stagnant nature of ideas for society, a body that is standing in the way of the change he is fighting for. As a reverend himself, King makes it clear that this disappointment could not exist "where there is not deep love," and that he still "sees the church as the body of Christ." This type of religious language shows that King is aware of his audience's religious leanings, and thus realizes he must not completely alienate them if he wants his points to get across. King ends his discussion of the church by stating that he hopes "the church as a whole will meet the challenge of this decisive hour," calling his fellow clergymen to rise to the occasion and assist his efforts in the Civil Rights Movement. King's awareness of his audience dictates the way that he paces his writing, therefore allowing him to lay out an argument specifically designed for their benefit.
King's control of rhetorical strategies helps him to construct the optimal argument for his point of view. He pays attention to critical details and keeps in mind the leanings of his audience. At the same time, King also keeps in mind that this piece can appeal to a broader audience than just the clergymen, giving him an opportunity to voice his opinions on one of the most substantial issues of the day. His call to action simply needed to be articulated as strongly as possible in order to increase momentum. King's talent as a writer and orator granted him the ability to be so influential during this critical moment in history. Letter from Birmingham Jail is thus an accurate and representative reflection of his strength.