What is the central contrast of the peom​

In literature, an author uses contrast when they describe the difference(s) between two or more entities. For example, in the first four lines of William Shakespeare's Sonnet 130, Shakespeare contrasts a mistress to the sun, coral, snow, and wire. Contrast is the antonym of simile.

in "letter from a birmingham jail," king argues that there are four basic steps in any nonviolent campaign: "[c]ollection of the facts to determine whether injustices exist; negotiation; self purification; and direct action." finally, direct action is taken and acts such as boycotts and sit-ins are staged.