Blackwell Reference Online

Extract

L ogic The kind of fallacy which does not occur in the logical form or structure of an argument, but is committed in various other ways and can be identified through analysis of its content and its context. Aristotle 's Sophistical Refutations was the first systematic study of informal fallacies, although many other forms were added by later authors. Aristotle divided all fallacies into those dependent on language (Latin in dictione ) and those outside of language (Latin extra dictionen ). Modern logic textbooks accordingly generally divide informal fallacies into fallacies of ambiguity and material fallacies. Fallacies of ambiguity arise from the ambiguity of words or sentences in which ambiguous words occur, such as the fallacies of accent, amphiboly, equivocation, composition, division, and secundum quid . Material fallacies are due to reasons other than the ambiguity of language and are further divided into the fallacies of relevance and insufficient evidence. The fallacy of relevance occurs in those arguments whose premises are logically irrelevant to the truth of the conclusion and are hence incapable of establishing it. Many informal fallacies of this kind have a Latin name of the form “ argumentum ad …,” such as argumentum ad baculum, argumentum ad hominem, argumentum ad ignorantiam, argumentum ad misericordiam, argumentum ad populum , and argumentum ad ... log in or subscribe to read full text