What technique does Thoreau use to refute Paley in paragraph 9 in Civil Disobedience

In this passage Thoreau counterargues Paley which states that people should always obey and abide by their government as long as the government gives them what they want or what is convinient. For this, Thoreau uses an analogy, the analogy goes "If I have unjustly wrested a plank from a drowning man, I must restore it to him though I drown myself." that is what is right must be done, in this case to end slavery and the war against Mexico, even if it costs people their existence, or in a less dramatical tone, even if means not to get as richer as they wanted.