A prominent motif running throughout Civil Disobedience is the opposition of true humanity to machines and machinery. For Thoreau, an individual who forfeits their own conscience in obedience to the state might be thought of as a sort of machine, and the state a complex system of machinery like those introduced to the United States during the Industrial Revolution. Of those men who “serve the State,” Thoreau writes:
The mass of men serve the State thus, not as men mainly, but as machines, with their bodies. They are the standing army, and the militia, jailers, constables, posse comitatus, &c. In most cases there is no free exercise whatever of the judgment or of the moral sense; but they put themselves on a level with wood and earth and stones; and wooden men can perhaps be manufactured that will serve the purpose as well.
Those who work for the government, Thoreau claims, follow instructions rather than their own free will. In casting aside their own “judgment” and “moral sense,” they reduce themselves to the “level with wood and earth and stones.” In other words, they are like automatons crafted from materials by the state rather than human beings divinely imbued with a moral compass. Such men, he asserts, could easily be replaced by “wooden men.”
Later in the essay, he compares the government to a vast machine in an extended metaphor:
If the injustice is part of the necessary friction of the machine of government, let it go, let it go: perchance it will wear smooth,—certainly the machine will wear out. If the injustice has a spring, or a pulley, or a rope, or a crank, exclusively for itself, then perhaps you may consider whether the remedy will not be worse than the evil.
Here, Thoreau reflects upon the relationship between injustice and the state. When a minor injustice is “a necessary friction of the machine of government,” it can be ignored until it “wears smooth” on its own. However, if “the injustice has a spring, or a pulley,” then that suggests that the machine of government requires injustice and should therefore be done away with. Thoreau’s machinery motif suggests that the government is a tool designed by humans than can similarly be replaced by human action.
