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Affirmative Conclusion From A Negative Premise
Affirmative conclusion from a negative premise (illicit negative) is a formal fallacy In philosophy, a formal fallacy, deductive fallacy, logical fallacy or non sequitur (; Latin for " tdoes not follow") is a pattern of reasoning rendered invalid by a flaw in its logical structure that can neatly be expressed in a standard logic syst ... that is committed when a categorical syllogism has a positive conclusion and one or two negative premises. For example: :''No fish are dogs, and no dogs can fly, therefore all fish can fly.'' The only thing that can be properly inferred from these premises is that some things that are not fish cannot fly, provided that dogs exist. Or: :''We don't read that trash. People who read that trash don't appreciate real literature. Therefore, we appreciate real literature.'' This could be illustrated mathematically as :If A \cap B = \emptyset and B \cap C = \emptyset then A\subset C. It is a fallacy because any valid forms of categorical syllogism that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formal Fallacy
In philosophy, a formal fallacy, deductive fallacy, logical fallacy or non sequitur (; Latin for " tdoes not follow") is a pattern of reasoning rendered invalid by a flaw in its logical structure that can neatly be expressed in a standard logic system, for example propositional logic.Harry J. Gensler, ''The A to Z of Logic'' (2010) p. 74. Rowman & Littlefield, It is defined as a deductive argument that is invalid. The argument itself could have true premises, but still have a false conclusion. Thus, a formal fallacy is a fallacy where deduction goes wrong, and is no longer a logical process. This may not affect the truth of the conclusion, since validity and truth are separate in formal logic. While a logical argument is a non sequitur if, and only if, it is invalid, the term "non sequitur" typically refers to those types of invalid arguments which do not constitute formal fallacies covered by particular terms (e.g., affirming the consequent). In other words, in practice, "''non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Categorical Syllogism
A syllogism ( grc-gre, συλλογισμός, ''syllogismos'', 'conclusion, inference') is a kind of logical argument that applies deductive reasoning to arrive at a conclusion based on two propositions that are asserted or assumed to be true. In its earliest form (defined by Aristotle in his 350 BCE book '' Prior Analytics''), a syllogism arises when two true premises (propositions or statements) validly imply a conclusion, or the main point that the argument aims to get across. For example, knowing that all men are mortal (major premise) and that Socrates is a man (minor premise), we may validly conclude that Socrates is mortal. Syllogistic arguments are usually represented in a three-line form: All men are mortal. Socrates is a man. Therefore, Socrates is mortal.In antiquity, two rival syllogistic theories existed: Aristotelian syllogism and Stoic syllogism. From the Middle Ages onwards, ''categorical syllogism'' and ''syllogism'' were usually used interchangeably. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Conclusion From Affirmative Premises
Negative conclusion from affirmative premises is a syllogistic fallacy committed when a categorical syllogism has a negative conclusion yet both premises are affirmative. The inability of affirmative premises to reach a negative conclusion is usually cited as one of the basic rules of constructing a valid categorical syllogism. Statements in syllogisms can be identified as the following forms: * a: All A is B. (affirmative) * e: No A is B. (negative) * i: Some A is B. (affirmative) * o: Some A is not B. (negative) The rule states that a syllogism in which both premises are of form ''a'' or ''i'' (affirmative) cannot reach a conclusion of form ''e'' or ''o'' (negative). Exactly one of the premises must be negative to construct a valid syllogism with a negative conclusion. (A syllogism with two negative premises commits the related fallacy of exclusive premises.) Example (invalid aae form): :Premise: All colonels are officers. :Premise: All officers are soldiers. :Conclusion: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fallacy Of Exclusive Premises
A fallacy is the use of invalid or otherwise faulty reasoning, or "wrong moves," in the construction of an argument which may appear stronger than it really is if the fallacy is not spotted. The term in the Western intellectual tradition was introduced in the Aristotelian '' De Sophisticis Elenchis''. Some fallacies may be committed intentionally to manipulate or persuade by deception. Others may be committed unintentionally because of human limitations such as carelessness, cognitive or social biases and ignorance, or, potentially, as the inevitable consequence of the limitations of language and understanding of language. This includes ignorance of the right reasoning standard, but also ignorance of relevant properties of the context. For instance, the soundness of legal arguments depends on the context in which the arguments are made. Fallacies are commonly divided into "formal" and "informal." A formal fallacy is a flaw in the structure of a deductive argument which r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
