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All the ideas for 'Thinking About Mathematics', 'Universals' and 'An Introduction to Modal Logic'

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33 ideas

4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 4. Soundness of PL
The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro]
5. Theory of Logic / K. Features of Logics / 4. Completeness
A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
Cauchy gave a formal definition of a converging sequence. [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
Categories are the best foundation for mathematics [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro]
A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro]
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro]
Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro]
Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
'Impredicative' definitions refer to the thing being described [Shapiro]
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
One moderate nominalist view says that properties and relations exist, but they are particulars [Armstrong]
8. Modes of Existence / B. Properties / 13. Tropes / b. Critique of tropes
If properties and relations are particulars, there is still the problem of how to classify and group them [Armstrong]
8. Modes of Existence / D. Universals / 1. Universals
Should we decide which universals exist a priori (through words), or a posteriori (through science)? [Armstrong]
8. Modes of Existence / D. Universals / 4. Uninstantiated Universals
It is claimed that some universals are not exemplified by any particular, so must exist separately [Armstrong]
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
'Resemblance Nominalism' finds that in practice the construction of resemblance classes is hard [Armstrong]
'Resemblance Nominalism' says properties are resemblances between classes of particulars [Armstrong]
8. Modes of Existence / E. Nominalism / 3. Predicate Nominalism
'Predicate Nominalism' says that a 'universal' property is just a predicate applied to lots of things [Armstrong]
8. Modes of Existence / E. Nominalism / 4. Concept Nominalism
Concept and predicate nominalism miss out some predicates, and may be viciously regressive [Armstrong]
'Concept Nominalism' says a 'universal' property is just a mental concept applied to lots of things [Armstrong]
8. Modes of Existence / E. Nominalism / 5. Class Nominalism
'Class Nominalism' may explain properties if we stick to 'natural' sets, and ignore random ones [Armstrong]
'Class Nominalism' says that properties or kinds are merely membership of a set (e.g. of white things) [Armstrong]
'Class Nominalism' cannot explain co-extensive properties, or sets with random members [Armstrong]
8. Modes of Existence / E. Nominalism / 6. Mereological Nominalism
'Mereological Nominalism' sees whiteness as a huge white object consisting of all the white things [Armstrong]
'Mereological Nominalism' may work for whiteness, but it doesn't seem to work for squareness [Armstrong]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]