Informal and Inductive Logic Knowledge Flashcards
explain: there are arguments that are semantically valid, but still logically unacceptable
Begging the question is a prime example of this since its conclusion is some version of the premise which is valid. But, it is not a good argument form since it is a fallacy.
explain: there are inferences that are semantically invalid, but are informally acceptable
Some arguments do not fulfill the requirements for being semantically valid but through context can be informally acceptable. For example, “Some S are not P” can be reasonably deduced from “Some S are P” because one assumes that if “All S are P,” the speaker would have stated that and not “some.” However, this logic is still formally invalid while being reasonable.
explain: it is possible to communicate something true by saying something false
It is possible to communicate something true by saying something false through the use of pragmatics such as tone, which can signify sarcasm, reversing the meaning of a statement.
explain the reasoning when someone infers Some S are not P from a speaker’s claim that Some S are P
One can infer Some S are not P from a speaker’s claim that Some S are P using the informal logic that if All S are P were true, the speaker would have said that instead of Some S are P.
Explain the following sentence: Many false dilemmas are cases of valid reasoning, but are pragmatically
unacceptable responses to the disagreements.
False dilemmas (false dichotomy) take the form of a disjunctive syllogism and can be formally valid reasoning; however, when the two potential options are not exclusive or when a third option exists, the disjunctive syllogism is invalid.
Explain the difference between extensional and intensional definitions.
Extensional definitions state all the objects that belong to a class, whereas intensional definitions state the requirements an object must meet to belong to a class.
Give an example of definition by synonym.
An attorney is a lawyer.
Define and give an example of ad hominem abusive fallacies. Explain what makes them fallacious.
Ad hominem abusive fallacies are distinguished by an attack on alleged character flaws of a person instead of the person’s argument, thus hurting the deliberation by discounting logic based on irrelevant claims. An example would be “you should not believe what he says about our economy because he is a left-leaning, card-carrying liberal”
Define and give an example of arguments from ignorance. Explain what would make an argument from
ignorance fallacious.
An argument from ignorance states that if there is no evidence for a proposition, then the proposition is false or unacceptable. An example would be “there is not evidence that Turner committed the crime, so Turner did not commit the crime.” An argument from ignorance can be fallacious if there exists no burden of proof or if the conclusion is hard to prove (i.e. the existence of God, the existence of aliens, etc)
Give an example of extensional definition by enumeration.
An “actor” is Robert Downey Jr., Matt Damon, Leonardo DiCaprio, Tom Hanks, Jennifer Lawrence . . .
Explain the following sentence: Given the pragmatic requirements of argument, successful arguers must
have a cognitive command of an issue and the debate in order to give dialectically proper arguments.
Because pragmatic arguments are concerned with the context of an argument and the question of rhetorical success, successful arguers must have a cognitive demand of an issue and the debate in order to convince the audience of the truth of the arguer’s argument through dialectics. Arguers must be able to understand the potential refutes to an argument and counter them accordingly.
Define equivocation. Give an example of an equivocal inference (or fallacy of equivocation).
Equivocation is using two instances of a term that have different meanings but are treated as the same word. An example would be “I can run faster than Donald Trump. Donald Trump is running a race for President. I would win the Presidency against Donald Trump.”
What is a complex question? Explain the following sentence: all questions are complex in some way or
other - the issue is whether they are objectionably complex.
A complex question is a question that presupposes some object or proposition to be true, thus providing confirmation of that proposition. Every question is complex in that the subject matter is assumed to be true (Why, what, or how x presupposes that x exists). However, when the object of the question is in contention, the complex question becomes objectionable. “Did you ever stop biting your nails?” is an objectionable complex question if you have never bitten your nails because it insinuates that at one point you did bite your nails.
What are the three primary critical questions to ask of any argument from authority?
Does the speaker have the authority?
Does the speaker say the proposition/object?
Is the proposition/object in the domain of the topic at hand?
Distinguish between the representational and selectional versions of the straw man fallacy (or: the straw man and the weak man).
The representational straw man fallacy misstates or otherwise morphs the argument of the opponent into an argument that is less acceptable or is illogical in order to misrepresent the opponent’s case. The selectional straw man (or weak man) fallacy chooses to argue only against the weaker arguments in a debate to create the appearance that the argument of the opponent is weak when stronger arguments for the same case exist.
