Exam 1 Flashcards
Argument are either
valid/invalid or strong/weak
Statements are either
true or false
Terms are either
clear or ambiguous
Premise indicators
since, because, for, given that, assuming that, etc
Conclusion indicators
so, thus, therefore, consequently, hence, which means that etc
Validity
if the premises are true then the conclusion must be true
Soundness
valid + all premises are true
A valid argument does not necessarily mean…
that the premises are actually in reality true
Extensional Definitions
list EXamples; dog-labrador, joes pet, german shepherd
Ostensive Definition
literally involves pointing to members ; pointing to a dog and saying “dog”
Enumerative Defintions
lists every individual (not kinds) ; like listing all southern states in the US
Subclass Defintion
lists every kind or group (not individuals)
Intensional Definition
indicates the characteristics a think MUST have in order to be considered a member of the clas; ex) dog: mammal, four legged, domesticated etc
Lexical Definition
traditional, customary, or common use (dictionary definition)
Theoretical Definition
tries to express a perfect understanding of the essence of what the term is talking about
Genus + Difference =
lexical defintion
Equivocation
shifts the meaning of a term from 1 to another
Amphiboly
like misunderstading something; a statement was meant in one way but interepreted differently
Composition
make a claim about the parts and then conclude that the whole must be the same; part to whole; taking something that is individual and applying it to the whole group; all parts of this plane are light, so the whole plane is light
Division
whole to part; if the group believes something then the individual also believes it;
Quantifier Shifts
premise may be about many, but the conclusoin is about a single thing
Token Type Shift
talking about a type but the reader/listener thought it was about individuals
A Statement
all S are P; universal affirmative
E Statement
No S are P; universal negative
I Statement
Some S are P; particular affirmative
O Statement
Some S are not P; particular negative
Simple Conversion
swap the subject and predicate; ONLY VALID on E and I statements;
Conversion by limitation
swap the subject and the predicate of A; change quantity from All to Some; only applies to A statements (which become I); ex) all dogs are animals. So,, some animals are dogs
Obversion
change the quality from affirm to negate (or vice versa); replace the predicate term with it term-complement; valid for ALL statement ; A becomes E (vice versa), I becomes O (vice versa); ex0 some dog are not brown things. So, some dogs are non-brown things.
Partial Contraposition
O-C; INVALID for I; A becomes E; E becomes I; and O becomes I; ex) All dogs are animals. So, no non-animals are dogs.
Full Contraposition
O-C-O; replace the subject with the term-complement of the predicate; replace the predicate with the term complement of the subject; ONLY APPLIES to A and O; ex) all dogs are animals. So all nonanimals are nondogs
Partial Conversion
C-O; A becomes O (By limitation); E becomes A; I becomes O; INVALID for O; ex) some dogs are brown things. So, some brown things are no nondogs
Full Inversion
C-O-C; ONLY valid for E which becomes I
