The "I Have a Dream" speech by Martin Luther King Jr. is a powerful and persuasive address that includes several instances of reasoning. One notable example is when King uses logical reasoning to argue for equality. For instance, when he says, "I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character," he employs reasoned arguments to highlight the injustice of racial discrimination, appealing to the audience's sense of logic and justice.