It may seem that the imputation of a foible or fault to a critic simply qua critic is always optional, never necessary to preserve the consistency of the theory or the good faith of the proponent. But this is not true. First, there is the case of the brazen theory which includes as a tenet the forthright equation of disagreement and error. This tenet is not as rare, nor probably as naive, as one might at first suspect. It may be called (using legal jargon) the "exclusivity clause" of the theory. Any theory may have an exclusivity clause, and most theories may have them without contradicting their own content. The "clause" merely states that the set of tenets comprising the theory is the truth and the only truth on its precise subject. It does not imply completeness; but it does imply that propositions inconsistent with the theory are false. It may be tacit and understood, and indeed it does seem to follow from the mere claim of truth according to the principle of excluded middle (tacit in many theories) and most classical notions of truth. If a theory contains an exclusivity clause, even a tacit one, it impels the good faith proponent to equate disagreement and error. Critics may courteously be indulged in the realm of debate, and cajoled into seeing the light, if possible, but that would be supererogatory under the canons of logic and good faith. One premise of "civilized" debate —that any contender might be speaking the truth and debate is one way to tell who— is not shared by all the contenders. For this reason it is disturbing to note that almost any claim to truth may bear a tacit exclusivity clause.
Even more disturbing is the case of philosophical systems. The paradigm of good philosophy for several western traditions —the complete, consistent system— is impelled to be rude. This is not news to Kierkegaard, who felt rudely subsumed by Hegel's system, and was told by contemporary Hegelians that he was logically incapable of attaining a perspective outside the system sufficient to attack it.
If the system is supposed to be complete as well as true, then the good faith proponent must believe the critic in error, and therefore must apply the system's explanation of error to her. Note that mere belief in the completeness and truth of the system suffices here to justify the conclusion that disagreement is error. The good faith proponent need not immediately act on this belief in the critic's error, but neither can he escape concluding it, any more than he could willingly suspend judgment on the truth of his beliefs. Proponents of what are supposed to be true, complete, consistent systems must choose between apostasy and rudeness. They must defend their beliefs either by appeal to premises and principles from outside the system, which they believe are false, or by appeal to premises and principles from withing the system, which is question-begging and liable to be very rude. This may be called the dilemma of systematic self-defense. To ask such a believer to be logically polite "just for the sake of argument" is equivalent to asking him to give up some tenets of the faith he wishes to defend just to enter a realm of debate to defend it. This is why systems with pretensions to completeness have traditionally seemed rude, have traditionally authorized rude defenses in their proponents, or have gone undefended at fundamental levels.
It is this feature in political systems which allows the equation of dissent and mental illness, dissent and crime, and dissent and error, and the feature which led modern philosophers like Kierkegaard and Nietzsche to abjure the pursuit of philosophical systems per se.
There may be more than rudeness to turn one from systems, but one should note that rudeness should not suffice, for falsehood cannot be inferred from mere rudeness. On the other hand, if systems are still attractive, this analysis indicates at least that the logic of defending systems is peculiar, and that if we still cherish both the pursuit of systems and the classical forms of debate, then we will have to forgive some question-begging and rudeness. Moreover, if this is so, we should expect a true system to take these peculiarities into account and present a logic in which some circular arguments and rude defenses are permissible. Hegel's system fulfills this expectation more than others, and perhaps the reason is that it is more self-conscious of the logic of systematicity than others.