Some of you have written to let me know the meaning of the word truculence. Thanks, but I am well aware of its meaning. I am also aware of basic grammar. Angelou's sentence makes no grammatical sense. Walls cannot have a "truculence to do" anything. If someone sent this sentence in unsolicited, the editors at the Washington Post would have sent it back, asking for it to be re-written in English. But it's Maya Angelou and so they printed it. Leave aside the self-righteous pretentiousness and the exhausted metaphor. The piece is laughably bad.