Combining Texts

All the ideas for 'Symbolic Reasoning', 'Whitehead and the Rise of Modern Logic' and 'Russell'

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5 ideas

4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
21548 The null class is the class with all the non-existents as its members [MacColl, by Lackey]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
13639 Quine says higher-order items are intensional, and lack a clearly defined identity relation [Quine, by Shapiro]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
6408 Russell needed three extra axioms to reduce maths to logic: infinity, choice and reducibility [Grayling]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
21557 Russell confused use and mention, and reduced classes to properties, not to language [Quine, by Lackey]
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
6414 Two propositions might seem self-evident, but contradict one another [Grayling]