16 terms

Introductory Logic by Nance and Wilson

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, then it is true

law of Non-Contradiction

a statement cannot be both true and false

formal logic

deals directly with the proper modes of reasoning

Informal Logic

deals with operations of thinking that are indirectly related to reasoning

induction

reasoning with probability from examples or experience to general rules

deduction

the reasoning with certainty from premises to conclusions

term

a concept that can be expressed precisely

Definition

a statement that gives the meaning of a term

ambiguous

a word is ambiguous if it has more than one possible meaning

Vague word

is one whose extent is unclear

genus of a term

is a term that is more general, broad, or abstract than the original term and includes it

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 sum of all the individual objects described by it

intension of a term

is the sum of all common attributes denoted by the term