UGC NET Paper 1 – Logical Reasoning (Comprehensive Notes)

Updated 2025 | Detailed notes on Logical Reasoning covering arguments, facts vs opinions, analogies, syllogism, Venn diagrams, and Indian logic with solved examples.

1️⃣ Structure of Arguments

An argument is a set of statements with premises supporting a conclusion. Understanding assumptions and evaluating strength is key in UGC NET.

Example: Premise: “All teachers attend training.” Conclusion: “Some teachers are well-trained.”
Explanation: The conclusion logically follows; at least some teachers are trained due to attending programs.

2️⃣ Facts vs Opinions

Facts are verifiable; opinions are subjective. NET questions ask to distinguish them in paragraphs.

Example: “The Earth revolves around the Sun. It is the most beautiful planet.”
Explanation: First is fact (proven), second is opinion (subjective).

3️⃣ Analogies and Syllogism

Analogies

Analogies show relationships between word pairs.

Example: “Painter : Brush :: Writer : Pen”
Explanation: Painter uses brush, writer uses pen. Analogies identify similar relationships.

Syllogism

Syllogism uses premises to reach a logical conclusion.

Example: Premises: “All dogs are animals. All animals have life.” Conclusion: “All dogs have life.”
Explanation: Deductive reasoning ensures conclusion follows logically.

4️⃣ Venn Diagrams and Logical Connectivity

Venn diagrams visualize relationships between sets. Circles = sets, overlaps = common elements.

Example 1: 50 students: 30 like Math, 25 like Science, 10 like both.
Solution: Only Math = 20, Only Science = 15, Both = 10, Neither = 5.

       _________
      /         \
     /  Math 20  \
    /     10      \
    \ Science 15 /
     \_________/

Explanation: Overlapping area = students liking both; non-overlapping = only one subject.

Example 2 (Three Sets): 100 students: Football 40, Cricket 50, Hockey 30, all three = 10, FC=5, CH=8, FH=7.
Only Football=18, Only Cricket=27, Only Hockey=5.

          (Football)
         _________
        /         \
       / 18   10   \
      / 7          \
      \     5      /
       \ (Cricket)/
        \_________/
         (Hockey)

Explanation: Diagram visualizes overlaps, exclusive sets, and intersections for logical reasoning.

5️⃣ Indian Logic (Anumana, Pramana, Hetvabhasa)

Classical Indian logic teaches reasoning methods:

• Anumana: Inference/deduction
• Pramana: Means of knowledge (perception, testimony, reasoning)
• Hetvabhasa: Fallacy in reasoning

Example: Premise: “Where there is smoke, there is fire.”
Explanation: Anumana = inference of fire from smoke. Hetvabhasa = claiming all smoky places are dangerous is a fallacy (overgeneralization).