LEGAL LOGIC & TECHNIQUE OUTLINE

ATENEO DE MANILA LAW SCHOOL

LEGAL TECHNIQUE & LOGIC OUTLINE1

ATTY. ALEXANDER C. DY

SECTION 1E, SECOND SEMESTER, SY 2005-2006

I.

II.

INTRODUCTION A.

History of Logic

B.

Civil Law vs. Common Law Tradition

C.

The Role of Logic in Law

REASONING A.

III.

Basic Concepts 1.

What is Logic

2.

Propositions and Sentences

3.

Arguments, Premises and Conclusions

4.

More Complex Arguments

5.

Recognizing Arguments

6.

Deduction and Induction

7.

Validity and Truth

8.

Arguments and Explanations

B.

Analyzing and Diagramming Arguments

C.

Problem Solving

LANGUAGE A.

1

15 NOVEMBER 2005

Uses of Language 1.

Three Basic Functions of Language

2.

Discourse Serving Multiple Functions

3.

Forms of Discourse

4.

Emotive Words

5.

Kinds of Agreement and Disagreement

6.

Emotively Neutral Language

The Outline presents the manner by which Legal Technique & Logic will be taken up in class. The Outline is taken mainly from Introduction to Logic by Irving M. Copi and Carl Cohen.

2

B.

IV.

Definition 1.

Disputes, Verbal Disputes and Definitions

2.

Kinds of Definition and the Resolution of Disputes

3.

Denotation (Extension) and Connotation (Intension)

4.

Extension, and Denotative Definitions

5.

Intension, and Connotative Definition

6.

Rules for Definition by Genus and Difference

DEDUCTIVE REASONING A.

B.

C.

Categorical Propositions 1.

Categorical Propositions and Classes

2.

Quality, Quantity and Distribution

3.

The Traditional Square of Opposition

4.

Further Immediate Inferences

5.

Existential Import

6.

Symbolism and Diagrams for Categorical Propositions

Categorical Syllogisms 1.

Standard-Form Categorical Syllogisms

2.

The Formal Nature of Syllogistic Argument

3.

Venn Diagram: Technique for Testing Syllogisms

4.

Six Rules of Categorical Syllogisms

Arguments in Ordinary Language 1.

Reducing the Number of Terms in a Syllogistic Argument

2.

Translating Categorical Propositions into Standard Form

3.

Uniform Translation

4.

Enthymemes

5.

Sorites

6.

Disjunctive and Hypothetical Syllogisms

7.

The Dilemma

3

D.

E.

F.

V.

Symbolic Logic 1.

The Value of Special Symbols

2.

The Symbols for Conjunction, Negation, and Disjunction

3.

Conditional Statements and Material Implication

4.

Argument Forms and Arguments

5.

Statement Forms, Material Equivalence, Logical Equivalence

6.

The Paradoxes of Material Implication

7.

The Three “Laws of Thought”

The Method of Deduction 1.

Formal Proof of Validity

2.

The Rule of Replacement

3.

Proof of Invalidity

4.

Inconsistency

Quantification Theory 1.

Singular Propositions

2.

Quantification

3.

Traditional Subject-Predicate Propositions

4.

Proving Validity

5.

Proving Invalidity

6.

Asyllogistic Inference

INDUCTIVE REASONING A.

Inductive Generalizations (Induction by Simple Enumeration)

B.

Analogy and Probable Inference 1.

Analogy

2.

Appraising Analogical Arguments

3.

Refutation by Logical Analogy

C.

Causality

D.

Probability

4

VI.

FALLACIES A.

What is a Fallacy?

B.

Formal Fallacies 1.

2.

3.

C.

Fallacies in Categorical Syllogisms a.

Four Terms

b.

Undistributed Middle Term

c.

Illicit Major Term

d.

Illicit Minor Term

e.

Negative Premises

f.

Particular Premises

Fallacies in Hypothetical Syllogisms (Modus Ponens and Modus Tollens) a.

Denial of Antecedent

b.

Affirmation of Consequent

Fallacies in Disjunctive Syllogisms a.

Missing Disjuncts

b.

Nonexclusivity

Informal (Material) Fallacies 1.

Fallacies of Relevance a.

Argumentum ad Ignorantiam (Argument from Ignorance)

b.

Argumentum ad Misericordiam (Appeal to Pity)

c.

Argumentum ad Verecundiam (Appeal to Inappropriate Authority or Prestige)

d.

Argumentum ad Hominem (Argument against the Man) i. ii.

Abusive Circumstantial

e.

Argumentum ad Populum (Appeal to the Masses)

f.

Argumentum ad Baculum (Appeal to Force)

g.

Argumentum ad Antiquitam (Appeal to the Ages)

h.

Argumentum ad Terrorem (Appeal to Terror)

i.

Irrelevant Conclusion (Ignoratio Elenchi)

5

2.

j.

Tu Quoque (You Yourself Do It)

k.

Argumentum ad Nauseam

Fallacies of Presumption a.

Compound (Complex) Question

b.

False Cause i. ii.

3.

D.

Non cause pro causa Post hoc ergo propter hoc

c.

Non Sequitur (It Does Not Follow)

d.

Begging the Question (Petitio Principii)

e.

Accident (Dicto Simpliciter)

f.

Converse Accident (Hasty Generalization)

Fallacies of Ambiguity a.

Equivocation

b.

Amphibology

c.

Accent

d.

Composition

e.

Division

f.

Vicious Abstraction

Avoiding Fallacies

VII. SYNTHESIS AND APPLICATION