Combining Texts

All the ideas for 'Philosophical Fragments', 'Modality' and 'Abstraction Reconsidered'

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24 ideas

2. Reason / A. Nature of Reason / 1. On Reason
Consistency is modal, saying propositions are consistent if they could be true together [Melia]
4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC
Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets [Melia]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Second-order logic needs second-order variables and quantification into predicate position [Melia]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
If every model that makes premises true also makes conclusion true, the argument is valid [Melia]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
Abstraction from objects won't reveal an operation's being performed 'so many times' [Geach]
7. Existence / A. Nature of Existence / 5. Reason for Existence
I assume existence, rather than reasoning towards it [Kierkegaard]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
No sort of plain language or levels of logic can express modal facts properly [Melia]
Maybe names and predicates can capture any fact [Melia]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia]
10. Modality / A. Necessity / 2. Nature of Necessity
Nothing necessary can come into existence, since it already 'is' [Kierkegaard]
We may be sure that P is necessary, but is it necessarily necessary? [Melia]
10. Modality / A. Necessity / 4. De re / De dicto modality
'De re' modality is about things themselves, 'de dicto' modality is about propositions [Melia]
10. Modality / B. Possibility / 1. Possibility
Sometimes we want to specify in what ways a thing is possible [Melia]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Possible worlds make it possible to define necessity and counterfactuals without new primitives [Melia]
In possible worlds semantics the modal operators are treated as quantifiers [Melia]
If possible worlds semantics is not realist about possible worlds, logic becomes merely formal [Melia]
Possible worlds could be real as mathematics, propositions, properties, or like books [Melia]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / b. Worlds as fictions
The truth of propositions at possible worlds are implied by the world, just as in books [Melia]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
If concepts are just recognitional, then general judgements would be impossible [Geach]
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
For abstractionists, concepts are capacities to recognise recurrent features of the world [Geach]
18. Thought / E. Abstraction / 8. Abstractionism Critique
The abstractionist cannot explain 'some' and 'not' [Geach]
Only a judgement can distinguish 'striking' from 'being struck' [Geach]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia]