At trial, a civil disobedient may appeal to his reasonable belief in the unconstitutionality of the law that he violated. However, he cannot appeal to any technical difficulties that would require him to lie about his performance of the act in question, or about the role of his conscience in motivating his action.
"Response to Professor Marshall Cohen,"
Philosophic Exchange: Vol. 1
, Article 2.
Available at: http://digitalcommons.brockport.edu/phil_ex/vol1/iss1/2