# Logic

 Logic: The study of the methods and principles used to distinguish correct from incorrect reasoning Argument: from logitians point of view, is a series of propositions, some of which are premises, others of which are conclusions Logic is not: 1. Science of thought (psychology)2. Science of reasoning(cog. psy.)3. The art of persuasion "rhetoric" We are interested in: causes us to think the way we do Propositions, while expressed by sentences: they are not equivalent to sentences Questions and explanations : are sentences but not propositions Commands: are sentences but not propositionsThese Can be turned into propositions though Example of command: Do your homework -> You should doyour homework if you want topass the class. Temporal relations; prop. that appears to be butisntone indicating a before and afterex. since the nig has been president, the economy has gone to hell. Arguments do not = explanations Conditional statement(hypothetical) while not; an argument it can still be part of onecompound prop. it is false only when the antecedent is true and the consequent is false Proposition: An assertion that something is (or isnt) the case; they are either true or false Inductive: invalidif premises are true doesnt mean conclusion ispremises only make the conc. LIKELY to true but not absolutely*prediction of future is always inductive Deductive validqif premises are true then the con. has to be true Four kinds of inductive arguments 1. predictions about future2. argument from analogy3. inductive generalization4. causal inferences Argument from analogy the premises indicate how a number of objects are similar and inferences drawn, given that it is reasonable to say they are similar in ways we dont know about and ways we do Example of arg. from analogy Tom and Hank and Dick all own BMW Z3 2009 built in GreerTom and Dick's cars get 37 miles togallon (we dont know how much Hanks gets but we assmue it is the same) Inductive generalization The premises give us information about a sample (subset) of some group. The conclusion is that the findinngs of the sample are true for the whole. We generalize Causal inference Has premises that provide that something has happened, the con. provides some causation of the event.Causes and effects Example of Causal inference I forgot to put the ice cream up before i went to bed (we infer a certain effect) infer that itmelted. - Maybe someone else put it away...there are alternative accounts forother reasons If i intend that my premises are saying the truth for the conclusion, then it is deductive Deductive can only either be; valid invalid Refutation by counter example 1. If A, then B2. Not A3. Not B If obama were a rockstar he'd be famousObama isnt a fockstarObama isnt famous Classical logic traditional techniquesbased on aristotles works for the analyses of deductive arguments Fallacy a type of argument that may seem to be correct but contains a mistake in reasoning Fallacies of Relevance fallacies in which the premises are irrelecent to the conclusion 5 types of fallacies of relevance 1. the appeal to emotion2. the appealto pity3. the appealto force4. argument against the person5. irrelevant conclusion Appeal to emotion Fallacy in which the argument relies on emotion rather than reason.ad populumboarders on brainwashingtype of propaganda...bandwagon effect Appeal to pity fallacy in which the arg. relies on gerosity, altruism, or mercy, rather than reason Appeal to force fallacy in which the arg relies on the threat of force; threat may be veiled. Argument ad hominem fallacy in which the erg. relies on an attack against the person taking a positioncan be abusive or circumstantial Irrelevent conclusion type of fallacy in which the premises support a different con. than the one that is proposed Fallacies of presumption fallacies in which the con. depends on a tacit assumption that is dubious, unwarranted, or false Types of presumption fallacies 1. fallacy of accident2. complex question3. begging the question Fallacy of accident fallacy in which a generalization is wrongly applied to a particular case Complex question fallacy in which a question is asked in a way that presupposes the truth of some proposition buried within the question Begging the question fallacy in which the con. is stated or assumed within one of the premisesalso known as circular argument Fallacies of ambiguity fallacies causes by a shift or confusion of meanings within an argument types of ambiguity fallacies 1. fallacy of equivocation2. fallacy of amphiboly3. fallacy of accent4. fallacy of composition5. fallacy of division Fallacy of equivocation fallacy in which 2 or more meanings of a word or phrase are used in different parts of an argument Fallacy of amphiboly fallacy in which a loose or awkward combination of words can be interpreted in more than 1 way.The premise is based on 1 interpretation while the con. relies on a different interpretation Fallacy of accent fallacy in which a phrase is used to convey 2different meanings within an arg. and the difference is based on changes in emphasis given to words within a phrase Fallacy of composition fallacy in which an inference is mistakenly drawn from the attributes of the parts of a whole, to the attributes of the whole Fallacy of division fallacy in which a mistaken inference is drawn from the attributes of a whole to the attributes of the parts of the whole Authorfaulkebr ID119558 Card SetLogic DescriptionBasic Logical Concepts Updated2011-11-29T15:36:22Z Show Answers