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 IT IS TRUE.

THE LAW OF NON-CONTRADICTION

A STATEMENT CANNOT BE

BOTH TRUE AND FALSE.

FORMAL LOGIC

DEALS WITH THE PROPER

MODES OF REASONING

INFORMAL LOGIC

DEALS WITH OPERATIONS OF THINKING THAT

ARE INDIRECTLY REALTED TO REASONING

INDUCTION

IS REASONING WITH PROBABILITY FROM

EXAMPLES OR EXPERIENCE TO

GENERAL RULES

DEDUCTION

IS REASONING WITH CERTAINTY

FROM PREMISES TO

CONCLUSIONS

SYLLOGISM

IS A TYPE OF DEDUCTIVE ARGUMENT

IN WHICH THE CONCLUSION

CONNECTS ONE CATEGORY

WITH ANOTHER

A TERM

IS A CONCEPT THAT CAN BE

EXPRESSED PRECISESLY

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 WHOSE EXTENT IS UNCLEAR

A STIPULATIVE DEFINITION

IS WHEN A NEW WORD IS INVENTED

OR AN EXISTING WORD IS

APPLIED IN A NEW WAY

A LEXICAL DEFINITION

SHOWS RELATIONSHIPS OR REDUCES

AMBIGUITY BY PROVIDING A SINGLE

ESTABLISHED MEANING OF A TERM

THEORETICAL DEFINITIONS

ARE OF TEN SCIENTIFIC OR

OR PHILOSOPHICAL IN NATURE

PERSUASIVE DEFINITIONS

AIM AT PERSUADING THE LISTENER

ONE WAY OR ANOTHER TOWARD TH

TERM BEING DEFINED

A GENUS

OF A TERM IS A TERM THAT IS MORE

GENERAL, BROAD OR ABSTRACT

THAN THE ORIGINAL TERM AND

INCLUDES IT

A SPECIES

OF A TERM IS A TERM THAT IS MORE

SPECIFIC, NARROW OR CONCRETE THAN

THE ORIGINAL TERM AND IS

INCLUDED BY IT

THE EXTENSION

OF A TERM IS THE SUM OF ALL THE

INDIVIDUAL OBJECTS DESCRIBED BY IT

THE INTENSION

OF A TERM IS THE SUM OF ALL THE

COMMON ATTRIBUTES DENOTED

BY THE TERM

A DIFFERENCE

IN THIS METHOD, A TERM IS DEFINED BY

NAMING ITS GENUS AND THEN ADDING

DESCRIPTIVE WORDS WHICH DISTINGUISH

THAT TERM FROM EVERY OTHER SPECIES

UNDER THE GENUS.

CONSISTENT

IS WHEN TWO STATEMENTS

CAN BE TRUE AT THE

SAME TIME

INCONSISTENT

WHEN THERE IS A CONFLICT

BETWEEN THE STATEMENTS

IMPLICATION

IS WHEN TWO STATEMENTS ARE RELATED

BECAUSE THE TRUTH OF ONE

REQUIRES THE TRUTH

OF THE OTHER.

LOGICALLY EQUIVALENT

IS WHEN TWO STATEMENTS

IMPLY ONE ANOTHER

INDEPENDENT

IS WHEN THE TRUTH OR FALSITY

OF ONE HAS NO EFFECT ON THE

TRUTH OR FALSITY OF THE OTHER

REAL DISAGREEMENT

IS AN ACTUAL INCONSISTENCY BETWEEN

TWO STATEMENTS:

THEY BOTH CANNOT BE TRUE

AT THE SAME TIME

APPARENT

DISAGREEMENT

IS A DIFFERENCE OF OPINION OR

PERCEPTION, BUT THERE IS

NO LOGICAL CONTRADICTION

VERBAL

 DISAGREEMENT

IS A MISUNDERSTANDING

DUE TO DIFFERING DEFINITIONS

OF ONE OR MORE WORDS