Splendid Sentences, Part 4: Martin Luther King Jr. on Injustice

Toward the end of his fabled 8,000-word "Letter from Birmingham City Jail" (April 1963), Martin Luther King Jr. juxtaposes these two sentences:

If I have said anything in this letter that is an overstatement of the truth and is indicative of an unreasonable patience, I beg you to forgive me. If I have said anything in this letter that is an understatement of the truth and is indicative of my having a patience that makes me patient with anything less than brotherhood, I beg God to forgive me.

While King's essay served as an open letter to society for any newspaper or magazine that would publish it—and many did—he actually opened it with "My dear Fellow Clergymen," in response to those ministers, priests, and rabbis who claimed that his brand of civil disobedience was not akin to Gandhi's nonviolent protest movement of a generation earlier, but tantamount to a criminal conduct that threatened to undermine the very goals he set for his civil rights campaign. 

Why are these two sentences so powerful? I can think of at least three reasons.

• Rhetorical repetition figures prominently in King's speeches and not so much in his prose, but not here. The first 18 words of both sentences are identical, except for the one in polar opposite of the other (overstatement and understatement), creating a rhythm that makes the prose dance.
• Dramatic contradiction is another device King uses, not at all unique to him. (Remember "Ask not what your country can do for you; ask what you can do for your country," or "Some men see things as they are, and ask why; I dream of things that never were, and ask why not.") He shows his human limitations by admitting to the possibility of overstating to the point of inappropriate fervency toward jurisprudence and law enforcement, as well as understating to the point of unforgivable indifference to humanity. 
• Divine refutation borders on divine fallacy in most cases, but we must remember the men of the cloth who were the intended recipients of these sentences. They are in the God business. King asks them to forgive his overstating his point, which he believes can hardly be overstated; however, he asks the far greater authority of God to forgive any chance of his standing where his opponents do. And, of course, we can forgive impatience toward injustice quicker than we can a contempt toward brotherhood.

"Letter from Birmingham City Jail" contains numerous other rhetorical devices that make it worth reading in full.