In "Civil Disobedience," Henry David Thoreau explains the morality that governs his choices. His fundamental moral rule is to follow his own conscience. Abiding by this rule is difficult, he acknowledges, because it may require a person to disobey a law that they believe is unjust. Among the examples he provides are condemning slavery and war.
To follow the law rather than one’s own conscience would be, for Thoreau, to abdicate personal responsibility. Each person must decide on their own course of action as a moral issue because such choices have perpetual, spiritual consequences, not just temporary, terrestrial ones.
Thoreau says that he has both the right and the obligation not to support laws that condone things that he believes are wrong.
The only obligation which I have a right to assume is to do at any time what I think right.
An individual could act from the basis of their convictions to get laws changed, but that is not their primary duty; opposition is.
What I have to do is to see…that I do not lend myself to the wrong which I condemn.
The imperative of personal conviction is not removed by any governmental actions. In his view, the state does not have the authority to requires anyone “to be the agent of injustice to another.” If such a demand is made, then “break the law.”
His fundamental understandings about civic duty supported Thoreau’s position on paying taxes that would support an unjust war, which the United States was waging against Mexico—a position that landed him in jail.