Combining Texts

All the ideas for 'Elucidation of some points in E.Schröder', 'Is Hume's Principle analytic?' and 'Letters to De Vries'

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3 ideas

4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set

14238

A class is an aggregate of objects; if you destroy them, you destroy the class; there is no empty class [Frege]

9. Objects / D. Essence of Objects / 14. Knowledge of Essences

4869	Experience does not teach us any essences of things [Spinoza]

18. Thought / E. Abstraction / 7. Abstracta by Equivalence

8693	An 'abstraction principle' says two things are identical if they are 'equivalent' in some respect [Boolos]