Paine's argument throughout Common Sense relies heavily upon a logical fallacy: he consistently appeals to God as the definitive moral authority. In making this appeal to authority a core part of his argument, Paine assumes that his readership is composed entirely of Christians; for any person who is not a Christian, however, the argument would immediately fall to pieces. Take this passage, for instance, wherein Paine references a Bible passage condemning monarchy:
When a man seriously reflects on the idolatrous homage which is paid to the persons of Kings, he need not wonder, that the Almighty ever jealous of his honor, should disapprove of a form of government which so impiously invades the prerogative of heaven. Monarchy is ranked in scripture as one of the sins of the Jews, for which a curse in reserve is denounced against them. The history of that transaction is worth attending to.
Though Paine might have been warranted, at the time of his writing this, in assuming that most of his readership were Christians, the appeal to authority in this passage represents a fallacy nonetheless. If a person does not believe in sin as a concept, the language condemning monarchy as such would have no effect.
Paine's appeal to divine authority, while a fallacy, also represents the crux of his moral argument: his ethos, or means of establishing credibility with his audience as he argues against the monarchy, hinges on his ability to refer to a moral authority higher than himself or any other earthly being.
While the majority of Paine's rhetoric is consistent and highly persuasive, he does rely upon certain logical fallacies in his argument: namely, circular reasoning. In this passage from the third section of Common Sense, he asserts that the British monarchy should not be able to control America, because America is such a far distance away from the British Isles:
Even the distance at which the Almighty hath placed England and America, is a strong and natural proof, that the authority of the one, over the other, was never the design of Heaven. The time likewise at which the continent was discovered, adds weight to the argument, and the manner in which it was peopled increases the force of it. The reformation was proceeded by the discovery of America, as if the Almighty graciously meant to open a sanctuary to the persecuted in future years, when home should afford neither friendship or safety.
The existence of something cannot serve as justification for its own existence. If a person plans to rob a bank and executes that robbery, the fact that they took such an action at the time and in that manner does not justify the action itself. One cannot say, "I did it, therefore it is morally acceptable that I did it." Likewise, the timeline proceeding from the Reformation to the American Revolution cannot, by virtue of its existence, justify the actions of the American Revolution. This is the fallacy of appealing to fate or predetermination: Paine invokes God, but this invocation cannot quite cover up the illogical nature of his circular fallacy.
