statement
a declarative sentence that makes a claim and only has one of two truth values (is either true or false)
truth values
true or false
declarative sentence
makes a claim or states something
inference
the reasoning process expressed by an argument
argument
establishes support for the truth of a claim ; contains premise(s) and a conclusion
inference
a conclusion based on the process of evidence and reasoning
indicators
used to identify arguments
conclusion indicators
therefore
consequently
this proves that
thus
in conclusion
suggests
so
it follows that
implies that
hence
premise indicators
because
assuming that
as indicated by
since
as shown by
the fact that
given that
for the reason(s) that
it follows from
explanation
uses "because" to provide reasons for how an event occurred ; provides reasons for an already accepted fact
truth value analysis
determines if the information in the premises is accurate, correct, or true
(analyzes truth of information)
logical analysis
determines the strength with which the premises support the conclusion
(analyzes argument form)
deductive argument
arguent in which it is claimed that:
1. the conclusion follows necessarily from the premise(s)
2. true premises make it impossible for the conclusion to be false
most restrictive argument form ; premise MUST cause conclusion
inductive argument
argument in which it is claimed that:
1. the premise(s) make the conclusion probably
2. true premises make it improbable for the conclusion to be false
least restrictive argument form; premises CAN cause conclusion
deductive argument indicators
necessarily, certainly, definitely
mathematics, geometry, definitions
inductive argument indicators
probably, likely, unlikely, plausible
analogical, legal, moral, statistical, scientific
valid deductive argument
if the premises are true, the conclusion can never be false
invalid deductive argument
even if the premises are true, it is still possible for the conclusion to be false
sound deductive argument
the argument is valid and the premises are, in fact, true
satisfies truth value and logical analysis
unsound deductive argument
the argument is invalid or at least one premise is false
doesn't satisfy either truth value analysis, logical analysis, or both
logical form
helps to separate logical analysis from truth analysis
statement counterexample
provides evidence that a statement is false
[automatically creates an unsound deductive argument]
argument counterexample
shows that true premises do not necessarily make the conclusion true
[automatically creates an invalid argument & exposes flaws in deductive argument form]
invalid argument form
A is C
A is T
T is C
valid argument form
A is C
T is C
A is T
strong inductive argument
true premises make it probable that the conclusion is true
weak inductive argument
true premises do not make it probable that the conclusion is true
[automatically creates uncogent argument]
poor logical form
cogent inductive argument
the argument is strong and the premises are true
uncogent inductive argument
the argument is weak or has at least one false premise
enthymemes
arguments with missing premises, missing conclusions, or both
principle of charity
we should choose a (stronger) reconstructed argument (usually with enthymemes) that gives the benefit of the double to the person presenting the argument
--> infers hidden premises, but the original argument is still weak
--> primarily applied when trying
inferential claim
tells us whether an argument is inductive or deductive
term
a single word or group of word that can be the subject of a statement; it can be a common name, a proper name, or even a descriptive phrase
ambiguity, vagueness, imprecision
in order to clearly support the truth of a conclusion, premises must avoid the following...
intension
specified by listing the properties or attributes that the term connotes
(lists specific connotations / aspects)
extension
the class or collection of objects to which the term applies
(larger class/ group, applied to reality)
increasing intension
in a sequence of terms, each term connotes more attributes than the previous term; increases specificity
increasing extension
in a sequence of terms, each term denotes a set of objects with more members than the previous term; increases broadness
synonymous definition
assigns a meaning to a term by providing another with the same meaning
(intensional)
word origin definition
a meaning is assigned to a term by investigating its origin
(intensional
operational definition
defines a term by specifying a measurement procedure ex) academic achievement & GPA ; unobservable phenomenon (radioactivity)
(intensional)
definitions by genus and difference
assigns a meaning to a term (the species) by establishing a genus and combining it with the attribute that distinguishes the members of that species
(intensional)
ostensive definitions
involves physically demonstrating the term
ex) pointing, nonverbal behavior, gesturing, drawing, showing photos
(extensional)
enumerative definitions
assigns meaning to a term by naming the individual members of the classes denoted by the term
ex) "New England" means CT, NY, etc
(extensional)
complete enumeration
enumerative definition that lists all class members
partial enumeration
enumerative definition that doesn't list all class members
definition by subclass
assigns meaning to a term by naming subclasses (species) of the class denoted by the term
ex) "coal" means lignite, sub bituminous, etc
(extensional)
complete definition by subclass
definition by subclass that lists all species in a class
partial definition by subclass
definition by subclass that doesn't list all species in a class
stipulative definition
everyday definition that introduces a new meaning to a term or symbol
(intensional & extensional)
lexical definition
everyday definition based on the common use of a word, term, or symbol ; commonly used in dictionaries
(intensional & extensional)
functional definition
everyday definition that specifies the purpose or use of objects denoted by the term
(extensional)
precising definition
everyday definition that reduces the vagueness and ambiguity of a term by providing a sharp focus, often a technical meaning, for a term
theoretical definition
everyday definition that assigns a meaning to a term by providing an understanding of how the term fits into a general theory
persuasive definition
everyday definition that assigns a meaning to a term with the direct purpose of influencing attitudes or opinions ; goal is not to provide information but influence thinking about emotionally charges issues
guidelines for informative definitions
1. appropriately uses quotation marks
2. includes essential meaning of term
3. not too broad or narrow
4. not circular
5. affirmative and not negative
6. doesn't use ambiguous or vague language
7. doesn't use emotionally charged or figurative language
8.
cognitive meaning
language that is used to convey information and has cognitive meaning
emotive meaning
language that is used to express emotion or feelings ; contains a value claim
value claim
a judgment that someone (or something ) is good or bad, moral or immoral, or better or worse than another person ( or thing )
factual dispute
occurs when people disagree on factual matters
--> emotional attitudes towards facts complicate this
verbal dispute
occurs when a vague or ambiguous term results in linguistic misunderstandings
--> makes it difficult to agree on a definition
argument diagrams
allows us to visualize the connections between the premise(s) and the conclusion
independent premises
the falsity of one premise doesn't nullify any support the other the other premise gives to a conclusion
dependent premises
premises that act together to support a conclusion
convergent diagram
diagrams independent premises
linked diagram
diagrams dependent premises
divergent diagram
diagrams a single premise supporting independent conclusions
serial diagram
diagram that shows a conclusion from one argument is a premise in a second argument
rhetorical language
speaking or writing for dramatic or exaggerated effect, using language that may be implying things that are not explicitly said
rhetorical questions
a statement disguised in the form of a question
ex) do you really think you can afford a car?
rhetorical conditionals
a conditional statement that is used to imply an argument and can be reconstructed in different ways, depending on context
ex) if you truly care about your children, then why are you neglecting them?
rhetorical disjunctions
a disjunction used to disguise a statement or implied argument ; two parts don't appear to connect
ex) if you don't agree with our country's policies, then why don't you go live in another country?
formal fallacy
a logical error in a deductive argument that occurs in the form or structure of an argument
informal fallacy
a mistake in reasoning that occurs in ordinary language, including mistakes due to relevance, unwarranted assumption, ambiguity, and diversion
argument against the person (ad hominem)
a claim or argument is rejected based solely on alleged character flaws, negative stereotypes, or life circumstances of the person making the claim, without rational engagement with the person's claim or argument
poisoning the well
informal fallacy that points out false or outrageous things that this person said on previous occasions, often before the opponents get the chance to present their arguments
tu quoque
informal fallacy that avoids the issue at hand by claiming the other person is a hypocrite
appeal to the people
the avoidance of objective evidence in favor of an emotional response, defeating a rational investigation of truth
appeal to pity
an emotional please that relies solely on a sense of pity for support
appeal to force/ fear
a threat of harmful consequences used to force acceptance of a course of action that would otherwise be unacceptable
appeal to nausea
argument claims that, purely for the reason that some argument has been presented often before, it should be disregarded
(one is sick of hearing it)
genetic fallacy
the origin of something or someone is cited in order to discredit it , but this origin or the history of the thing, word or person in question are irrelevant to the argument
etymological fallacy
a type of genetic fallacy, where the origin of a word, is employed and is often irrelevant to its current meaning
rigid application of a generalization
a generalization is inappropriately applied to the case at hand
(weak inductive argument)
hasty generalization
a generalization created on the basis of a few instances ; qualitative
(weak inductive argument )
composition
the mistaken transfer of an attribute of the individual parts of an object to the object as a whole
small --> large
(weak inductive argument )
division
the mistaken transfer of an attribute of an object as a whole to its individual parts
large --> small
(weak inductive argument )
biased sample
uses a non-representative sample as support for a statistical claim about an entire population ; quantitative
(weak inductive argument )
false cause fallacies
occur when a causal connection is assumed to exist between two events when none actually exists
post hoc fallacy
fallacy that involves a short term pattern noticed after the fact and assumes a vague correlation is the cause, when in reality, it is not
post hoc coincidence
the simplest form of a post hoc fallacy that results from the accidental or chance connection between two events
ex) dreams & car wreck --> dreams predict car wrecks
post hoc common cause
post hoc fallacy that assumes one event causes another when both events result from a separate common cause
ex) atmospheric pressure , barometer, storms
slippery slope fallacy
false cause fallacy that attempt to make a final event the inevitable (usually catastrophic) outcome of an initial act, through a serious of allegedly inevitable steps
fallacies of unwarranted assumptions
arguments that assume the truth of some unproved or questionable claim
begging the question
assumes as evidence in the premises the very thing that it attempts to prove in the conclusion; premise and conclusion says the same thing
(fallacy of unwarranted assumption)
complex question
a single question that actually contains multiple, hidden parts ; automatically implies two things
(fallacy of unwarranted assumption)
appeal to ignorance
an argument built on a position of ignorance claiming either:
1. a statement must be true because it has not been proven false or
2. a statement must be false because it has not been proven true
--> conclusion based on lack of evidence
(fallacy of unwarra
appeal to unqualified authority
relies on the opinions of people who have no expertise, training, or knowledge relevant to the issue at hand
(fallacy of unwarranted assumption)
false dichotomy / false dilemma
a fallacy that occurs when it is assumed that only two possibilities exist, when in fact there are others ; two choices are presented, each leading to an unwarranted result, with failure to acknowledge that other possibilities exist.
ex) either you agree
fallacies of diversion
a fallacy that occurs when the meanings of terms or phrases or changed (intentionally or unintentionally) within the argument, or when our attention is purposely (or accidentally) diverted from the issue at hand
equivocation
the intentional or unintentional use of different meanings of words or phrases in an argument ; solved by providing context
ex) cool & cucumber
(fallacy of diversion)
straw man fallacy
occurs when someone's written or spoken words are taken out of context, purposely distorting the original argument to create a new, weak argument that can be easily refuted ; words taken out of context
(fallacy of diversion)
red herring fallacy
occurs when someone completely ignores an opponent's position and changes the subject, diverting the discussion in a new direction; most obvious when the topic is completely changed and paired with ad hominem attacks
(fallacy of diversion)
misleading precision
a claim that appears to be statistically significant , but is not
ex) cookies are 20% less fat
(fallacy of diversion)
missing the point
when premises that seem to lead to one conclusion are used instead to try to support another conclusion, which does not follow necessarily from the premises; premises support an incorrect conclusion
(fallacy of diversion)