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All the ideas for 'Metaphysics: contemporary introduction', 'The Problem of the Essential Indexical' and 'Logic in Mathematics'

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32 ideas

2. Reason / D. Definition / 3. Types of Definition
A 'constructive' (as opposed to 'analytic') definition creates a new sign [Frege]
2. Reason / D. Definition / 10. Stipulative Definition
Frege suggested that mathematics should only accept stipulative definitions [Frege, by Gupta]
2. Reason / E. Argument / 6. Conclusive Proof
We must be clear about every premise and every law used in a proof [Frege]
5. Theory of Logic / A. Overview of Logic / 3. Value of Logic
Logic not only proves things, but also reveals logical relations between them [Frege]
5. Theory of Logic / A. Overview of Logic / 8. Logic of Mathematics
Does some mathematical reasoning (such as mathematical induction) not belong to logic? [Frege]
The closest subject to logic is mathematics, which does little apart from drawing inferences [Frege]
5. Theory of Logic / E. Structures of Logic / 8. Theories in Logic
'Theorems' are both proved, and used in proofs [Frege]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Tracing inference backwards closes in on a small set of axioms and postulates [Frege]
The essence of mathematics is the kernel of primitive truths on which it rests [Frege]
Axioms are truths which cannot be doubted, and for which no proof is needed [Frege]
A truth can be an axiom in one system and not in another [Frege]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
To create order in mathematics we need a full system, guided by patterns of inference [Frege]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers
If principles are provable, they are theorems; if not, they are axioms [Frege]
8. Modes of Existence / B. Properties / 13. Tropes / b. Critique of tropes
If abstract terms are sets of tropes, 'being a unicorn' and 'being a griffin' turn out identical [Loux]
8. Modes of Existence / D. Universals / 1. Universals
Austere nominalists insist that the realist's universals lack the requisite independent identifiability [Loux]
Universals come in hierarchies of generality [Loux]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
Austere nominalism has to take a host of things (like being red, or human) as primitive [Loux]
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
Nominalism needs to account for abstract singular terms like 'circularity'. [Loux]
9. Objects / A. Existence of Objects / 5. Individuation / c. Individuation by location
Times and places are identified by objects, so cannot be used in a theory of object-identity [Loux]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Every concept must have a sharp boundary; we cannot allow an indeterminate third case [Frege]
11. Knowledge Aims / A. Knowledge / 4. Belief / b. Elements of beliefs
Indexicals are a problem for beliefs being just subject-proposition relations [Perry]
18. Thought / B. Mechanics of Thought / 5. Mental Files
We need definitions to cram retrievable sense into a signed receptacle [Frege]
We use signs to mark receptacles for complex senses [Frege]
19. Language / A. Nature of Meaning / 6. Meaning as Use
A sign won't gain sense just from being used in sentences with familiar components [Frege]
19. Language / C. Assigning Meanings / 9. Indexical Semantics
If we replace 'I' in sentences about me, they are different beliefs and explanations of behaviour [Perry]
Indexicals individuate certain belief states, helping in explanation and prediction [Perry]
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
Thoughts are not subjective or psychological, because some thoughts are the same for us all [Frege]
A thought is the sense expressed by a sentence, and is what we prove [Frege]
19. Language / D. Propositions / 5. Unity of Propositions
The parts of a thought map onto the parts of a sentence [Frege]
19. Language / D. Propositions / 6. Propositions Critique
Indexicals reveal big problems with the traditional idea of a proposition [Perry]
27. Natural Reality / D. Time / 2. Passage of Time / c. Tenses and time
Tense is essential for thought and action [Perry, by Le Poidevin]
Actual tensed sentences cannot be tenseless, because they can cite their own context [Perry, by Le Poidevin]