Combining Texts

Ideas for 'Introduction to Russell's Theory of Types', 'Logic (Port-Royal Art of Thinking)' and 'On the Source of Necessity'

expand these ideas     |    start again     |     choose another area for these texts

display all the ideas for this combination of texts

---

2 ideas

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4

15102

S4 says there must be some necessary truths (the actual ones, of which there is at least one) [Cameron]

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / p. Axiom of Reducibility

18170

The Axiom of Reducibility is self-effacing: if true, it isn't needed [Quine]