Nature and Scope of Logic
What the exam tests
This domain opens the paper with conceptual questions: what logic is, why it is called a normative science, and how logical form differs from subject matter. Expect short-answer items asking you to distinguish logic from psychology and to classify its branches.
Core rules and concepts
- Logic studies arguments: it evaluates the formal relation between premises and conclusion, not the truth of the premises themselves.
- It is normative (how we ought to reason), not descriptive psychology (how people actually think). This is the most commonly examined distinction.
- Logical form is the skeleton left when content is replaced by symbols; logical matter is the actual subject matter.
- Deductive reasoning claims the conclusion follows necessarily; inductive reasoning claims probability only.
- Branches: traditional (Aristotelian) and modern (symbolic); formal and material; pure and applied.
Worked example
“All metals expand when heated; copper is a metal; therefore copper expands when heated.” Strip the content: All M are P; S is M; therefore S is P. The form is valid - if the premises were true, the conclusion could not be false. Validity does not depend on whether copper really expands; that is a question for physics, not logic.
Traps that cost marks
Do not say logic “proves” premises true; it tests inference. Do not reverse normative and descriptive. Do not confuse “logic is both a science and an art” with the claim that it is a natural science.