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All the ideas for 'Thinking About Mathematics', 'The Theory of Objects' and 'The Metaphysics of Modality'

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46 ideas

1. Philosophy / E. Nature of Metaphysics / 2. Possibility of Metaphysics
There must be a plausible epistemological theory alongside any metaphysical theory [Forbes,G]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / a. Symbols of PL
The symbol 'ι' forms definite descriptions; (ιx)F(x) says 'the x which is such that F(x)' [Forbes,G]
4. Formal Logic / E. Nonclassical Logics / 6. Free Logic
So-called 'free logic' operates without existence assumptions [Meinong, by George/Van Evra]
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 / E. Structures of Logic / 2. Logical Connectives / d. and
Is the meaning of 'and' given by its truth table, or by its introduction and elimination rules? [Forbes,G]
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]
7. Existence / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
Vagueness problems arise from applying sharp semantics to vague languages [Forbes,G]
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
There can be impossible and contradictory objects, if they can have properties [Meinong, by Friend]
9. Objects / A. Existence of Objects / 3. Objects in Thought
There are objects of which it is true that there are no such objects [Meinong]
Meinong says an object need not exist, but must only have properties [Meinong, by Friend]
9. Objects / A. Existence of Objects / 4. Impossible objects
Meinong said all objects of thought (even self-contradictions) have some sort of being [Meinong, by Lycan]
The objects of knowledge are far more numerous than objects which exist [Meinong]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
In all instances of identity, there must be some facts to ensure the identity [Forbes,G]
9. Objects / B. Unity of Objects / 3. Unity Problems / d. Coincident objects
If we combined two clocks, it seems that two clocks may have become one clock. [Forbes,G]
9. Objects / D. Essence of Objects / 3. Individual Essences
Only individual essences will ground identities across worlds in other properties [Forbes,G, by Mackie,P]
An individual essence is a set of essential properties which only that object can have [Forbes,G]
Non-trivial individual essence is properties other than de dicto, or universal, or relational [Forbes,G]
9. Objects / D. Essence of Objects / 5. Essence as Kind
Essential properties depend on a category, and perhaps also on particular facts [Forbes,G]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
Essential properties are those without which an object could not exist [Forbes,G]
9. Objects / D. Essence of Objects / 11. Essence of Artefacts
Same parts does not ensure same artefact, if those parts could constitute a different artefact [Forbes,G]
Artefacts have fuzzy essences [Forbes,G]
9. Objects / E. Objects over Time / 12. Origin as Essential
An individual might change their sex in a world, but couldn't have differed in sex at origin [Forbes,G]
9. Objects / F. Identity among Objects / 1. Concept of Identity
Identities must hold because of other facts, which must be instrinsic [Forbes,G, by Mackie,P]
10. Modality / A. Necessity / 4. De re / De dicto modality
De re modal formulae, unlike de dicto, are sensitive to transworld identities [Forbes,G]
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
De re necessity is a form of conceptual necessity, just as de dicto necessity is [Forbes,G]
10. Modality / E. Possible worlds / 1. Possible Worlds / c. Possible worlds realism
Unlike places and times, we cannot separate possible worlds from what is true at them [Forbes,G]
The problem with possible worlds realism is epistemological; we can't know properties of possible objects [Forbes,G]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Possible worlds are points of logical space, rather like other times than our own [Forbes,G]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
Transworld identity concerns the limits of possibility for ordinary things [Forbes,G]
The problem of transworld identity can be solved by individual essences [Forbes,G]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Counterpart theory is not good at handling the logic of identity [Forbes,G]
10. Modality / E. Possible worlds / 3. Transworld Objects / d. Haecceitism
Haecceitism attributes to each individual a primitive identity or thisness [Forbes,G]
We believe in thisnesses, because we reject bizarre possibilities as not being about that individual [Forbes,G]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]