# Introduction to Logic

bisuvodu's version from 2018-02-05 06:33

## Section 1

Logic the study of the methods and principles used to distinguish correct from incorrect reasoning
Proposition assertion in language that is true or false. May be simple
Hypothetical or conditional propositions If then
Inference one proposition is arrived at and affirmed on the basis of some other proposition or (s) // the process
argument collection of propositions ( 1 conclusion / more than 1 proportion
premises proposition as to which you use inference to prove
Conclusion proposition that gives support to premises
Conclusion Indicator ( therefore ) a word or phrase appearing in an argument and usually indicating that what follows it is the conclusion or the argument
premises indicators ( because ) in an argument, a word or phrase that normally signals that what follows it are statements serving as premises
Invalid if premises is true but conclusion is false
Fallacy a type of argument that seems to be correct, but contains a mistake in reasoning
Black or White Fallacies offering two extremes when there are alternatives
Fallacies of Relevance premises are irrelevant to the conclusion
Non Sequitur does not follow ( conclusion simply does not follow from the premises
Fallacy of Defective induction premises are too weak or ineffective to warrant the conclusion

## Section 2

Appeal to the Populace bandwagoninformal fallacy when the support given for some conclusion is an appeal to a popular belief
Appeal to Pity emotion argument relies on generosity, altruism, or mercy rather than reason. ( got pulled over make up story, commercials to feed kids )
Red Herring attention is deliberately deflected away from the issue under the discussion (Duke university in 2006 the rape case argued that the real disaster was the American population below poverty line )
The straw Man simplifying something in order to attack it ( voodoo doll )
Argument ad Hominem relies upon an attack against the person taking a position ( consider the source attacking the person instead of what he said ) ( hypocrite )
Appeal to Force ( ad baculum ) argument relies upon an open to veiled threat of force ( robbed at gun point // curfew or grounded )
Missing the point irrelevant conclusion premises support a different conclusion from the one that is proposed ( the 1st amendment gives you the right to have a talk show not the qualification
Argument from ignorancelack knowledge proposition is held to be true just because it has not been proven false because it has not be proven true
Appeal to Inappropriate Authority Celebrities selling cereal conclusion is accepted as true simply because an expert has said that it is true
False Cause something that is not really the cause of something else is treated as its cause ( superstition wishing bad on something )
Post Hoc Ergo Propter Hoc an event is presumed to have been caused by a closely preceding event
Slippery slope change in a particular direction is asserted to lead inevitably to further changes in the same direction
Hasty Generalization defective induction in which one moves carelessly from a single case to a large scale generalization about all or most cases
Fallacy of Presumptions conclusion depends on a tacit assumption that is false ( have you stopped beating your wife )
Fallacy of Accident generalization is mistakenly applied to a particular case to which the generalization does not apply
complex questioninformal fallacy in which a question is asked in such a way as to presuppose the truth of some conclusion buried in that question
begging the question informal fallacy in which the conclusion of an argument is stated. ( circular argument )
Fallacy of Equivocation shifting the meaning by a word or phrase
Fallacy of Ambiguity shift or confusion in the meanings of words or phrases
Fallacy of Amphiboly ambiguity based on grammatical error ( misplaced modifiers or pronouns )
Fallacy of Accent putting emphasis on a definition only different word each time written
Fallacy of Composition Part --- > Whole ( argument erroneously assigns attributes ti a whole based on the fact that parts of that whole have attributes. ( airplanes are lightweight )
Fallacy of Divisions ambiguity in which an argument erroneously assigns attributes to parts of a whole