These misleading appearances are often connected to various aspects of natural language, such as ambiguous or vague expressions, or the assumption of implicit premises instead of making them explicit.
One such framework proposed is the dialogical approach, which conceives arguments as moves in a dialogue-game aimed at rationally persuading the other person.
Another conception, more common in non-scholarly discourse, sees fallacies not as arguments but rather as false yet popular beliefs.
This brings with it various difficulties not faced when studying formal fallacies, like ambiguous terms, vague expressions or the premises being assumed implicitly rather than stated explicitly.
[5][3][1] Deductively valid arguments offer the strongest form of support: for them, it is impossible for the conclusion to be false if all the premises are true.
But it can easily be modified to include informal fallacy by replacing this condition with a more general term, like logical weakness or incorrect reasoning.
This problem also involves social studies in order to determine which reference group of people to consult for defining fallacies.
[3][6][7][8] They are of special interest to the field of formal logic but they can only account for a small number of the known fallacies, for example, for affirming the consequent or denying the antecedent.
[17][12] Part of the difficulty in analyzing informal fallacies is due to the fact that their structure is not always clearly expressed in natural language.
[1] In some domestic quarrels and political debates, it is not clear from the outset what the two parties are arguing about and which theses they intend to defend.
[18] One way to explain that some fallacies do not seem to be deductively invalid is to hold that they contain various hidden assumptions, as is common for natural language arguments.
[3][1] It has been suggested that there may not be one single framework for evaluating all fallacies but only a manifold of ideals according to which a given argument may be good or bad.
The dialogical approach uses a game-theoretic framework to define arguments and sees fallacies as violations of the rules of the game.
The dialogical approach sees arguments not simply as a series of premises together with a conclusion but as a speech act within a dialogue that aims to rationally persuade the other person of one's own position.
[3] This explains, for example, why arguments that are accidentally valid are still somehow flawed: because the arguer himself lacks a good reason to believe the conclusion.
[2][12] A purely logical approach, on the other hand, fails to explain the fallacious nature of begging the question since the argument is deductively valid.
On this view, reasoning based on an argument can be interpreted as a process of changing one's degrees of belief, usually in response to new incoming information.
Fallacies of ambiguity often result in merely verbal disputes: the arguing parties have different topics in mind and thereby talk past each other without being aware of this.
[23][12] One way to avoid or solve these fallacies is to clarify language, e.g. by committing to definitions and by introducing new distinctions.
[24] Such reformulations may include a condensation of the original argument in order to make it easier to spot the erroneous step.
[12] The fallacy of division is committed if one infers from the sentence in the collective sense that one specific individual is strong enough.
Our liability to commit false dilemmas may be due to the tendency to simplify reality by ordering it through either-or-statements.
Hasty generalization, on the other hand, involves the converse mistake of drawing a universal conclusion based on a small number of instances.
Detecting this fallacy can be difficult when a complex argument with many sub-arguments is involved, resulting in a large circle.
[12][8] They may succeed in persuading the audience nonetheless due to being emotionally loaded (for example: by playing on prejudice, pity or fear).
It is a common and reasonable practice in court, for example, to defend oneself against an accusation by casting doubt on the reliability of the witnesses.
The difference between fallacious and justified ad hominem arguments depends on the relevancy of the character of the attacked person to the thesis in question.
Whataboutism is a special form of the ad hominem fallacy that attempts to discredit an opponent's position by charging them with hypocrisy without directly refuting or disproving their argument.
[36][12] Without this relevance, the argument constitutes a faulty or false analogy, for example: "If a child gets a new toy he or she will want to play with it; So, if a nation gets new weapons, it will want to use them".
[3] Etymological fallacies may confuse older or "original" meanings of words with current semantic usage.