Thoreau sees a moral distinction between failing to prevent an injustice and actually causing an injustice. Consider an example. Thoreau argues that the United States' invasion of Mexico is immoral and that Americans who support the government with their person (as soldiers) or property (through taxes) are complicit in that injustice. He would further say that a person should go to jail rather than be responsible for that invasion. However, imagine a case in which another country was invading Mexico, but that by offering himself up as some sort of hostage and allowing himself to be imprisoned, he could stop that invasion. Thoreau would argue that while it would be perfectly moral to go to jail in this case, he would not be required to do so. As a human being, he may legitimately have other ends or goals that require him to be out of jail. It is not his job to promote the best world possible by any means necessary. All that can be asked of a person is that he not dirty his own hands with injustice. Once this requirement is fulfilled, each individual should decide for himself what to do with his life. This distinction is rooted in Thoreau's belief that individuals should look inward for how they should live their lives. A person's primary duty is to be true to himself--to act with integrity and to pursue personal moral goals.
