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Intro Logic Lessons 1-15
Logic
59 cards·by ReaganWaggoner
challenge b
Logic
The science and art of reasoning well
Law of Excluded Middle
Any Statement is either true or false
Law of Identity
If a statement is true, than it is true
Law of Noncontradiction
A statement cannot be true and false
Formal Logic
Deals with the proper modes of reasoning
Informal Logic
Deals with the proper modes of reasoning that are indirectly related to reasoning
Induction
reasoning with probability from examples or experience to general rules
Deduction
Reasoning with certainty from premises to conclusions
Term
Concept expressed precisely in words
Definition
A statement that gives the meaning of a word
Ambiguous
More than one meaning
Vague
Extent is unclear
question
answer
Genus
more general, broad, or abstract than the original term and includes it
Species
More concrete or narrow than the original term and included by it
question
answer
mutually exclusive
terms don't overlap
exhaustive
no other types exist
extension
the sum of all the individual objects described by it
intension
the sum of all the individual attributes denoted by it
Defining by synonym
naming similar words
Defining by example
listing an example
Defining by example
listing an example
Defining by genus and difference
list the genus, and then similar words, separating them by their differences
Rules for defining by genus and difference #1
a definition should list the essential attributes of a term
Rules for defining by genus and difference #2
a definition should not be circular
Rules for defining by genus and difference #3
a a definition should not be too broad or too narrow
Rules for defining by genus and difference #4
A definition should be stated positively, if possible
Rules for defining by genus and difference #5
A definition should be the same part of speech as the term
Statement
sentence that is either true or false
What are three types of sentences that aren't statements
Questions, commands, and nonsense
Self-supporting statement
a statement that can be supported by the statement itself
tautology
a statement true by logical structure
Self-report
a statement considering a person's desires, beliefs, or feelings
Self-Contradiction
A statement false by logical structure
Supported Statement
a statement whose truth value depends on information outside the statement itself
What are the sources for supported statements?
experience, authority, and deduction
Consistency
If two statements can be true at the same time
Inconsistency
If there is a conflict between the statements
Implication
If the truth of one requires the truth of the other
Logical Equivalence
If the first implies the second, and the second implies the first
Independence
if the truth of the statements has nothing to do with the truth or falsity of the other
Real disagreement
An actual disagreement and both cannot be true at the same time
Apparent Disagreement
a difference in opinion or perception
Verbal disagreement
A misunderstanding due to different definitions for one or more words
Rules for changing to being verbs
identify and write down the entire subject, choose the proper to be verb, rewrite the entire
predicate as a predicate nominitave
Categorial statement
Something that confirms or denies something about the subject
4 forms of a categorial statement
all a are b, no s are p, some s are p, some s are not p
Subject
the term being described, or about which something is asserted
Predicate
something that describes or asserts something about the subject
Quantity of a Statement
the scope of its claim about the extension of the subject: universal or particular
Quality of a Statement
the positive or negative claim about the subject: affirmative or negative
The square of opposition
a diagram of the basic categorial relationships between categorial statements with the same
subject and predicate
Universal Affirmative Statements are known as
A Statements
Universal Negative Statements are known as
E Statements
Particular affirmative statements are known as
I Statements
Particular negative statements are known as
O statements
Contradiction
If two statements have opposite truth values
Contrary
If they can both be false but they cannot both be true