Combining Texts

All the ideas for 'The Evolution of Modern Metaphysics', 'First-Order Modal Logic' and 'Sameness and Substance Renewed'

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85 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Metaphysics is the most general attempt to make sense of things [Moore,AW]
1. Philosophy / F. Analytic Philosophy / 4. Conceptual Analysis
We learn a concept's relations by using it, without reducing it to anything [Wiggins]
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Each line of a truth table is a model [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / a. Symbols of ML
Modal logic adds □ (necessarily) and ◊ (possibly) to classical logic [Fitting/Mendelsohn]
We let 'R' be the accessibility relation: xRy is read 'y is accessible from x' [Fitting/Mendelsohn]
The symbol ||- is the 'forcing' relation; 'Γ ||- P' means that P is true in world Γ [Fitting/Mendelsohn]
The prefix σ names a possible world, and σ.n names a world accessible from that one [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / b. Terminology of ML
A 'constant' domain is the same for all worlds; 'varying' domains can be entirely separate [Fitting/Mendelsohn]
Modern modal logic introduces 'accessibility', saying xRy means 'y is accessible from x' [Fitting/Mendelsohn]
A 'model' is a frame plus specification of propositions true at worlds, written < G,R,||- > [Fitting/Mendelsohn]
A 'frame' is a set G of possible worlds, with an accessibility relation R, written < G,R > [Fitting/Mendelsohn]
Accessibility relations can be 'reflexive' (self-referring), 'transitive' (carries over), or 'symmetric' (mutual) [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / c. Derivation rules of ML
Negation: if σ ¬¬X then σ X [Fitting/Mendelsohn]
Disj: a) if σ ¬(X∨Y) then σ ¬X and σ ¬Y b) if σ X∨Y then σ X or σ Y [Fitting/Mendelsohn]
Existential: a) if σ ◊X then σ.n X b) if σ ¬□X then σ.n ¬X [n is new] [Fitting/Mendelsohn]
T reflexive: a) if σ □X then σ X b) if σ ¬◊X then σ ¬X [Fitting/Mendelsohn]
D serial: a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X [Fitting/Mendelsohn]
B symmetric: a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [n occurs] [Fitting/Mendelsohn]
4 transitive: a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [n occurs] [Fitting/Mendelsohn]
4r rev-trans: a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [n occurs] [Fitting/Mendelsohn]
If a proposition is possibly true in a world, it is true in some world accessible from that world [Fitting/Mendelsohn]
If a proposition is necessarily true in a world, it is true in all worlds accessible from that world [Fitting/Mendelsohn]
Conj: a) if σ X∧Y then σ X and σ Y b) if σ ¬(X∧Y) then σ ¬X or σ ¬Y [Fitting/Mendelsohn]
Bicon: a)if σ(X↔Y) then σ(X→Y) and σ(Y→X) b) [not biconditional, one or other fails] [Fitting/Mendelsohn]
Implic: a) if σ ¬(X→Y) then σ X and σ ¬Y b) if σ X→Y then σ ¬X or σ Y [Fitting/Mendelsohn]
Universal: a) if σ ¬◊X then σ.m ¬X b) if σ □X then σ.m X [m exists] [Fitting/Mendelsohn]
S5: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / b. System K
The system K has no accessibility conditions [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / c. System D
□P → P is not valid in D (Deontic Logic), since an obligatory action may be not performed [Fitting/Mendelsohn]
The system D has the 'serial' conditon imposed on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / d. System T
The system T has the 'reflexive' conditon imposed on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / e. System K4
The system K4 has the 'transitive' condition on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / f. System B
The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
The system S4 has the 'reflexive' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
System S5 has the 'reflexive', 'symmetric' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
Modality affects content, because P→◊P is valid, but ◊P→P isn't [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 5. Epistemic Logic
In epistemic logic knowers are logically omniscient, so they know that they know [Fitting/Mendelsohn]
Read epistemic box as 'a knows/believes P' and diamond as 'for all a knows/believes, P' [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 6. Temporal Logic
F: will sometime, P: was sometime, G: will always, H: was always [Fitting/Mendelsohn]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
The Barcan says nothing comes into existence; the Converse says nothing ceases; the pair imply stability [Fitting/Mendelsohn]
The Barcan corresponds to anti-monotonicity, and the Converse to monotonicity [Fitting/Mendelsohn]
5. Theory of Logic / F. Referring in Logic / 3. Property (λ-) Abstraction
(λx)[Man x] means 'the property x has iff x is a man'. [Wiggins]
'Predicate abstraction' abstracts predicates from formulae, giving scope for constants and functions [Fitting/Mendelsohn]
7. Existence / A. Nature of Existence / 6. Criterion for Existence
What exists can't depend on our conceptual scheme, and using all conceptual schemes is too liberal [Sider on Wiggins]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
We can accept criteria of distinctness and persistence, without making the counterfactual claims [Mackie,P on Wiggins]
Activity individuates natural things, functions do artefacts, and intentions do artworks [Wiggins]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
The idea of 'thisness' is better expressed with designation/predication and particular/universal [Wiggins]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
A sortal essence is a thing's principle of individuation [Wiggins, by Mackie,P]
Wiggins's sortal essentialism rests on a thing's principle of individuation [Wiggins, by Mackie,P]
The evening star is the same planet but not the same star as the morning star, since it is not a star [Wiggins]
'Sortalism' says parts only compose a whole if it falls under a sort or kind [Wiggins, by Hossack]
Identity a=b is only possible with some concept to give persistence and existence conditions [Wiggins, by Strawson,P]
A thing is necessarily its highest sortal kind, which entails an essential constitution [Wiggins, by Strawson,P]
Many predicates are purely generic, or pure determiners, rather than sortals [Wiggins]
The possibility of a property needs an essential sortal concept to conceive it [Wiggins]
9. Objects / B. Unity of Objects / 3. Unity Problems / d. Coincident objects
Objects can only coincide if they are of different kinds; trees can't coincide with other trees [Wiggins, by Sider]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Is the Pope's crown one crown, if it is made of many crowns? [Wiggins]
Boundaries are not crucial to mountains, so they are determinate without a determinate extent [Wiggins]
9. Objects / C. Structure of Objects / 5. Composition of an Object
Identity is an atemporal relation, but composition is relative to times [Wiggins, by Sider]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
If I destroy an item, I do not destroy each part of it [Wiggins]
9. Objects / D. Essence of Objects / 3. Individual Essences
We can forget about individual or particularized essences [Wiggins]
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
Essences are not explanations, but individuations [Wiggins]
9. Objects / D. Essence of Objects / 9. Essence and Properties
Essentialism is best represented as a predicate-modifier: □(a exists → a is F) [Wiggins, by Mackie,P]
9. Objects / D. Essence of Objects / 13. Nominal Essence
The nominal essence is the idea behind a name used for sorting [Wiggins]
9. Objects / E. Objects over Time / 4. Four-Dimensionalism
It is easier to go from horses to horse-stages than from horse-stages to horses [Wiggins]
9. Objects / E. Objects over Time / 9. Ship of Theseus
The question is not what gets the title 'Theseus' Ship', but what is identical with the original [Wiggins]
9. Objects / F. Identity among Objects / 1. Concept of Identity
Identity over a time and at a time aren't different concepts [Wiggins]
Hesperus=Hesperus, and Phosphorus=Hesperus, so necessarily Phosphorus=Hesperus [Wiggins]
9. Objects / F. Identity among Objects / 2. Defining Identity
The formal properties of identity are reflexivity and Leibniz's Law [Wiggins]
9. Objects / F. Identity among Objects / 3. Relative Identity
Relative Identity is incompatible with the Indiscernibility of Identicals [Wiggins, by Strawson,P]
Relativity of Identity makes identity entirely depend on a category [Wiggins]
To identify two items, we must have a common sort for them [Wiggins]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Indiscernibility of Identicals has been a big problem for modal logic [Fitting/Mendelsohn]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Do both 'same f as' and '=' support Leibniz's Law? [Wiggins]
Substitutivity, and hence most reasoning, needs Leibniz's Law [Wiggins]
10. Modality / E. Possible worlds / 1. Possible Worlds / d. Possible worlds actualism
Possible worlds rest on the objects about which we have suppositions [Wiggins]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / b. Worlds as fictions
Not every story corresponds to a possible world [Wiggins]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
□ must be sensitive as to whether it picks out an object by essential or by contingent properties [Fitting/Mendelsohn]
Objects retain their possible properties across worlds, so a bundle theory of them seems best [Fitting/Mendelsohn]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Counterpart relations are neither symmetric nor transitive, so there is no logic of equality for them [Fitting/Mendelsohn]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / b. Transcendental idealism
Appearances are nothing beyond representations, which is transcendental ideality [Moore,AW]
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
Asking 'what is it?' nicely points us to the persistence of a continuing entity [Wiggins]
18. Thought / D. Concepts / 2. Origin of Concepts / a. Origin of concepts
The mind conceptualizes objects; yet objects impinge upon the mind [Wiggins]
18. Thought / D. Concepts / 3. Ontology of Concepts / c. Fregean concepts
We can use 'concept' for the reference, and 'conception' for sense [Wiggins]
26. Natural Theory / B. Natural Kinds / 3. Knowing Kinds
Lawlike propensities are enough to individuate natural kinds [Wiggins]