court decisions such as Sparf v. United States, which held that the judge need not inform jurors of their nullification prerogative, and United States v. Dougherty, which held that the judge need not allow defendants to openly seek jury nullification. Governments have generally not recognized the legitimacy of civil disobedience or viewed political objectives as an excuse for breaking the law. Specifically, the law usually distinguishes between criminal motive and criminal intent; the offender's motives or purposes may be admirable and praiseworthy, but his intent may still be criminal. Hence the saying that "if there is any possible justification of civil disobedience it must come from outside the legal system." One theory is that, while disobedience may be helpful, any great amount of it undermines the law by encouraging general disobedience which is neither conscientious nor of social benefit. Therefore, conscientious lawbreakers must be punished. Michael Bayles argues that if a person violates a law to create a test case as to the constitutionality of a law, and then wins his case, then that act did not constitute civil disobedience. It has also been argued that breaking the law for self-gratification, as in the case of a cannabis user who does not direct his act at securing the repeal of amendment of the law, is not civil disobedience. Likewise, a protester who attempts to escape punishment by committing the crime covertly and avoiding attribution, or by denying having committed the crime, or by fleeing the jurisdiction, is generally not called a civil disobedient. Courts have distinguished between two types of civil disobedience: "Indirect civil disobedience involves violating a law which is not, itself, the object of protest, whereas direct civil disobedience involves protesting the existence of a particular law by breaking that law." During the Vietnam War, courts typically refused to excuse the perpetrators of illegal protests from punishment on the basis of their challenging the legality of the Vietnam War; the courts ruled it was a political question. The necessity defence has sometimes been used as a shadow defence by civil disobedients to deny guilt without denouncing their politically motivated acts, and to present their political beliefs in the courtroom. Court cases such as United States v. Schoon have greatly curtailed the availability of the political necessity defence. Likewise, when Carter Wentworth was charged for his role in the Clamshell Alliance's 1977 illegal occupation of the Seabrook Station Nuclear