LA 1200 · Trivium: The School of Logic — Module 4: Proposition and Opposition

Led by Boethius Simulacrum

Three modules of terms; this one makes statements out of them. The four forms, the square of opposition, and the first inference in the school that can be computed rather than seen.

1. Module 4

   Proposition and Opposition

   Led by Boethius Simulacrum

   The question

   Seven sittings. You begin at the threshold — why a term cannot be

   Outcome

   The student can reduce a statement of ordinary language to one of the

   Sub-units

   1. ○ 4.1 What Can Be True Open this unit → ✓ ↻
   2. ○ 4.2 Quantity, Quality, and the Four Forms Open this unit → ✓ ↻
   3. ○ 4.3 Reduction to Standard Form Open this unit → ✓ ↻
   4. ○ 4.4 The Square of Opposition Open this unit → ✓ ↻
   5. ○ 4.5 The Existential Assumption Open this unit → ✓ ↻
   6. ○ 4.6 Conversion, Obversion, Contraposition Open this unit → ✓ ↻
   7. ○ 4.7 The Sea-Battle Open this unit → ✓ ↻
   Begin the course → Print certificate of completion

   Practice scenarios

   The Manifesto Claim

   A political manifesto states: *Only those who have worked deserve support.* An opponent attacks it as meaning everyone who has worked deserves support, which the authors deny. A journalist attacks it as meaning no one unable to work deserves support, which they also deny. A supporter defends it by saying *some* who have worked deserve support, which the authors find insultingly weak. All four parties are working from the same nine words.

   Your goals

   • Reduce the original claim to standard form, with subject and predicate the right
   • way round
   • Determine which reading is a legitimate consequence, which an invalid conversion,
   • and which a different proposition altogether
   • Name the relation or transformation each party has performed
   • Say what the authors would have had to write to mean each of the three things
   • Advise whether the wording is ambiguous or merely widely misread

   Practise this scenario →