proper supposition

In logic, a supposition is an idea or assumption used as a starting point for an argument or investigation. The theory of supposition was a significant development in medieval logic, particularly from the late 12th century through the end of the Middle Ages.123

There are two main aspects to supposition theory:

1. Theory of Proper Supposition: This part addresses what a term in a proposition refers to. It distinguishes between:

   • Personal Supposition: The term refers to individual instances (e.g., "Every horse is an animal" - horse refers to individual horses).3
   • Simple Supposition: The term refers to a universal concept (e.g., "Horse is a species").3
   • Material Supposition: The term refers to the word itself (e.g., "Horse is a monosyllable").3

2. Types of Personal Supposition: This further categorizes personal supposition into types like determinate, confused and distributive, and merely confused, often analyzed through the concept of "descent to singulars".3

The theory of supposition was crucial for semantic analysis and was applied in logic, theology, and natural sciences. It is a foundational concept in understanding how terms function within propositions and arguments.3