84 terms

Challenge B introductory logic flashcrds

Logic is the science and art of reasoning well
The law of the excluded middle
Any statement is either true or false
The law of identity
If a statement is true, then a statement is true
The law of non contradiction
A statement cannot be both true and false
Formal logic
Formal logic deals with the proper modes of reasoning
Informal logic
Informal logic deals with operations of thinking that are indirectly related to reasoning
Induction is reasoning with probability from examples or experience to general rules
Deduction is reasoning with certainty from premises to conclusions
A term is a concept that can be expressed precisely
A definition is a statement that gives the meaning of a term
An ambiguous word has more than One definition
A vague word is one who's extent is unclear
Genus of a term
A genus of a term is a term that is more general, broad, or abstract then the original term and includes it
Species of a term
A species of a term is a term that is more specific, narrow or concrete than the original term and is included by it
Extension of a term
The extension of a term is the sum of all the individual objects described by it
Intension of a term
The intention of a term is the sum of all the common attributes denoted by the term
A statement is a sentence that is either true or false
Self-supporting statement
A self-supporting statement is a statement whose truth value can be determined from the statement itself
Tautology statement
A tautology is a statement which is always true because of its logical structure
A self-contradiction is a statement that is false due to its logical structure
Supported statement
A supported statement is a statement whose truth value depends on evidence or information from outside itself
Consistent statements
Two statements are consistent if they can both be true at the same time
Two statements are related by implication if the truth of one requires the truth of the other
Logically equivalent
Two statements are logically equivalent if they imply one another
Independent statements
Two statements are independent if the truth of falsity of one has no effect on the truth or falsity of the other
Real disagreement
A real disagreement is an actual inconsistency between two statements: they cannot both be true at the same time
Apparent disagreement
An apparent disagreement is a difference of opinion or perception
Verbal disagreement
A verbal disagreement is a misunderstanding due to differing definitions for one or more words
Subject of a statement
The subject of a statement is the term being described, or about which something was asserted
Predicate term
The predicate is the term that describes or asserts something about the subject
Quantity of a statement
The quantity of a statement is the scope of its claim about the extension of the subject: universal (entire extension) or particular (partial)
Quality of a statement
The quality of a statement is the positive or negative nature of its claim about the subject:affirmative (asserts something) or negative (denies something)
Square of opposition
the square of opposition is a diagram of the basic relationships between statements with the same subject and predicate
Contrary statements
Two statements are contrary if and only if they can both be false but cannot both be true
Subcontrary statements
Two statements are subcontraries if and only if both can be true but both cannot be false
Subimplication is the relationship between a universal and particular statement of the same quality, in which the truth of the universal necessitates the truth of the particular
Superimplication is the relationship between a universal and particular statement of the same quality
An argument is a set of statements, one of which appears to be implied or supported by the others
Conclusion of an argument
The conclusion of an argument is the statements which appears to be implied by the other statements in the argument, which are called premises
Categorical syllogism
A categorical syllogism is a deductive argument consisting of three statements in categorical form that together use only three terms, called the major, minor, and middle
Major term
The major term of a syllogism is the predicate of the conclusion and is used in one premise
Minor term
The minor term is the subject of the conclusion and is used in the other premise
Middle term
The middle term is found once in each premise
Major premise
The major premise of a syllogism is the premise containing the major term
Minor premise
The minor premise contains the minor term
Schema of a syllogism
The schema of a syllogism is a representation of it, having statements in standard order with standard abbreviations of its terms
Mood of a syllogism
The mood of a syllogism is a three-letter description of the types of categorical statements it contains when arranged in standard order
Figure of a syllogism
The figure of a syllogism is a number from 1 to 4 identifying the placement of its middle term
A valid syllogism
A syllogism is valid if the conclusion is necessarily true given that the premises are true
A sound syllogism
A sound syllogism is valid and has true premises
Counterexample of a syllogism
The counterexample of a syllogism is a syllogism of the same form as the original, but with obviously true premises and false conclusion, in order to show the original to be invalid
Distributed term
A distributed term is a term that, within a statement, refers to all the members of its class
Immediate inference
The immediate inference is a statement which can be inferred directly from another statement
Converse of a statement
The converse of a statement is a statement that reverses the subject and predicate. it is only valid for E and I
Obverse of a statement
The obverse of a statement is a statement of the opposite quality with a negated predicate. It is valid for all statements
Complement of a term
The complement of a term is the set of all terms not included in the given term. Thus the complement of the term P is non-P
Contrapositive of a statement
The contrapositive of a statement is a statement that reverses and negates both the subject and predicate of the original. It is valid for A and O
An enthymeme is an arguement in which a statement is unstated and assumed. Specifically, it is a syllogism with one assumed statement
A hypothetical is a statement that affirms an outcome based on a condition. It has the form If P then Q
Puere hypothetical syllogism
A pure hypothetical syllogism is an argument that uses only hypothetical statements
Antecedent of a hypothetical statement
The antecedent of a hypothetical statement is the condition, the part following the "if." The consequent is the result of the condition, the part after the "then"
The Latin phrase non sequitur
The Latin phrase non sequitur means "it does not follow"; i.e., that an arguement is invalid
Informal fallacy
An informal fallacy is a popular but invalid (or unhelpful) form of arguement
Fallacy of a distraction
A fallacy of a distraction is an argument that confuses the issue by pointing to information that is actually irrelevant to the conclusion
Ipse dixit
Ipse dixit is an illegitimate appeal to authority
Ad populum
Ad populum is an illegitimate appeal to authority
Ad baculum
Ad baculum is an illegitimate appeal to force
Ad hominim
Ad hominim is a verbal attack on a person rather than his arguement
Bulverism is attacking a position by pointing out how the arguer came to hold it
Tu quoque
Tu quoque points to an inconsistency between a person's argument and behavior
Ad ignorantiam
Ad ignorantium is an argument from lack of evidence
Chronological snobbery
Chronological snobbery is an argument based merely on the passage of time
Fallacies of ambiguity
Fallacies of ambiguity are arguments that confuse the real issue with multiple, vague, or otherwise uncleat meanings
Equivocation is changing the definition of a term in the middle of an arguement
Fallacy of the accent
The fallacy of the accent alters the meaning of a statement through changed emphasis
Amphiboly is a vagueness of grammar that disguises or alters meaning
Composition is the fallacy of transferring attributes from part to whole
Division is the fallacy of transferring attributes from whole to part
Fallacies of form
Fallacies of form are arguments that fail to establish their conclusions because of a weakness in logical structure
Circular reasoning
Circular reasoning is secretly assuming what you are trying to prove
Post hoc ergo propter hoc
Post hoc ergo propter hoc is improperly assuming that a sequence in time implies a cause and effect
Either/or is making an argument based on a false dilemma
A complex question
A complex question is a question crafted to exclude any possible legitimate response
Apriorism is a hasty generalization