Logic, from the Greek λογικός (logikos) is the study of reasoning. Logic is used in most intellectual activity, but is studied primarily in the disciplines of philosophy, mathematics, and computer science. Logic examines general forms which arguments may take which forms are valid, and which are fallacies.

It is one kind of critical thinking. In philosophy, the study of logic falls in the area of epistemology, which asks: “How do we know what we know?” In mathematics, it is the study of valid inferences within some formal language.


  • Nature of Logic:

Deduction and Induction

Truth and Validity

  • Definition:

Purposes of Definition

Verbal Disputes and Definition

Types of Definition, Rules of Definition

  • Categorical Propositions:

Kinds of Propositions

Traditional Square of Opposition

Immediate Inferences

Existential Import

  • Categorical Syllogism:

Standard Form Categorical Syllogism

Venn Diagram Technique for Testing Syllogism

Rules and Fallacies

  • Symbolic Logic:

Value of Special Symbols,

Symbols for Conjunction,

Negation, and Disjunction,

Conditional Statements,

Material Implication

Argument Forms and Arguments

Statement. Forms and Statements Paradoxes of Material Implication

  • Method of Deduction:

Formal Proof of Validity

Rule of Replacement, Inconsistency

  • Qualification Theory:

Singular Propositions,


Propositional Function subject Predicate Propositions

Proving Validity

  • Causal Connections:

Mill’s Methods of Experimental Inquiry

Meaning of Cause, Mill’s Methods

Critique of Mill’s Methods

Defense of Mill’s Methods

Criticism of Stebbing and Russell

  • Science and Hypothesis:

Value of Science

Explanation: Scientific and Unscientific

Evaluation of Scientific Explanation of Scientific Explanation

Crucial Experiments and Adhoc Hypotheses

Classification of Hypotheses

Books Recommended

1. Copi, Irving, M. Introduction to Logic, 8th ed. New York: MacMillan, 1990.

2. Hurley, Patrick, J. A Concise Introduction to Logic, Belmont: Wadsworth Publishing Co. 1988.