Ideas from 'Intro to 'Philosophy of Logic'' by Dale Jacquette [2002], by Theme Structure
[found in 'Philosophy of Logic: an anthology' (ed/tr Jacquette,Dale) [Blackwell 2002,0631218688]].
green numbers give full details 
back to texts

expand these ideas
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic
9456

Modal logic is multiple systems, shown in the variety of accessibility relations between worlds

5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
9457

The two main views in philosophy of logic are extensionalism and intensionalism

5. Theory of Logic / I. Semantics of Logic / 5. Extensionalism
9458

Extensionalists say that quantifiers presuppose the existence of their objects

5. Theory of Logic / I. Semantics of Logic / 6. Intensionalism
9461

Intensionalists say meaning is determined by the possession of properties

19. Language / C. Assigning Meanings / 7. Extensional Semantics
9459

Extensionalist semantics is circular, as we must know the extension before assessing 'Fa'

9460

Extensionalist semantics forbids reference to nonexistent objects
