Combining Texts

All the ideas for 'Notes on John Wilkins', 'Varieties of Things' and 'Principia Mathematica'

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59 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / d. Philosophy as puzzles
Philosophy tries to explain how the actual is possible, given that it seems impossible [Macdonald,C]
1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
'Did it for the sake of x' doesn't involve a sake, so how can ontological commitments be inferred? [Macdonald,C]
2. Reason / F. Fallacies / 5. Fallacy of Composition
Don't assume that a thing has all the properties of its parts [Macdonald,C]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
The best known axiomatization of PL is Whitehead/Russell, with four axioms and two rules [Russell/Whitehead, by Hughes/Cresswell]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / p. Axiom of Reducibility
Russell saw Reducibility as legitimate for reducing classes to logic [Linsky,B on Russell/Whitehead]
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Russell denies extensional sets, because the null can't be a collection, and the singleton is just its element [Russell/Whitehead, by Shapiro]
We regard classes as mere symbolic or linguistic conveniences [Russell/Whitehead]
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
Lewis's 'strict implication' preserved Russell's confusion of 'if...then' with implication [Quine on Russell/Whitehead]
Russell's implication means that random sentences imply one another [Lewis,CI on Russell/Whitehead]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
Russell unusually saw logic as 'interpreted' (though very general, and neutral) [Russell/Whitehead, by Linsky,B]
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
In 'Principia' a new abstract theory of relations appeared, and was applied [Russell/Whitehead, by Gödel]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / i. Reals from cuts
A real number is the class of rationals less than the number [Russell/Whitehead, by Shapiro]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / a. Defining numbers
Russell takes numbers to be classes, but then reduces the classes to numerical quantifiers [Russell/Whitehead, by Bostock]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
Russell and Whitehead were not realists, but embraced nearly all of maths in logic [Russell/Whitehead, by Friend]
Russell and Whitehead took arithmetic to be higher-order logic [Russell/Whitehead, by Hodes]
'Principia' lacks a precise statement of the syntax [Gödel on Russell/Whitehead]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
The ramified theory of types used propositional functions, and covered bound variables [Russell/Whitehead, by George/Velleman]
The Russell/Whitehead type theory was limited, and was not really logic [Friend on Russell/Whitehead]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
In 'Principia Mathematica', logic is exceeded in the axioms of infinity and reducibility, and in the domains [Bernays on Russell/Whitehead]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
Russell and Whitehead consider the paradoxes to indicate that we create mathematical reality [Russell/Whitehead, by Friend]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
To avoid vicious circularity Russell produced ramified type theory, but Ramsey simplified it [Russell/Whitehead, by Shapiro]
7. Existence / C. Structure of Existence / 2. Reduction
Reduce by bridge laws (plus property identities?), by elimination, or by reducing talk [Macdonald,C]
8. Modes of Existence / A. Relations / 2. Internal Relations
Relational properties are clearly not essential to substances [Macdonald,C]
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
Being taller is an external relation, but properties and substances have internal relations [Macdonald,C]
8. Modes of Existence / B. Properties / 12. Denial of Properties
Does the knowledge of each property require an infinity of accompanying knowledge? [Macdonald,C]
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
Tropes are abstract (two can occupy the same place), but not universals (they have locations) [Macdonald,C]
Properties are sets of exactly resembling property-particulars [Macdonald,C]
Tropes are abstract particulars, not concrete particulars, so the theory is not nominalist [Macdonald,C]
8. Modes of Existence / B. Properties / 13. Tropes / b. Critique of tropes
How do a group of resembling tropes all resemble one another in the same way? [Macdonald,C]
Trope Nominalism is the only nominalism to introduce new entities, inviting Ockham's Razor [Macdonald,C]
8. Modes of Existence / D. Universals / 2. Need for Universals
Numerical sameness is explained by theories of identity, but what explains qualitative identity? [Macdonald,C]
8. Modes of Existence / D. Universals / 6. Platonic Forms / b. Partaking
How can universals connect instances, if they are nothing like them? [Macdonald,C]
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
Real Nominalism is only committed to concrete particulars, word-tokens, and (possibly) sets [Macdonald,C]
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
Resemblance Nominalism cannot explain either new resemblances, or absence of resemblances [Macdonald,C]
9. Objects / A. Existence of Objects / 5. Individuation / c. Individuation by location
A 'thing' cannot be in two places at once, and two things cannot be in the same place at once [Macdonald,C]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
We 'individuate' kinds of object, and 'identify' particular specimens [Macdonald,C]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
Unlike bundles of properties, substances have an intrinsic unity [Macdonald,C]
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
The bundle theory of substance implies the identity of indiscernibles [Macdonald,C]
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
A phenomenalist cannot distinguish substance from attribute, so must accept the bundle view [Macdonald,C]
When we ascribe a property to a substance, the bundle theory will make that a tautology [Macdonald,C]
Substances persist through change, but the bundle theory says they can't [Macdonald,C]
A substance might be a sequence of bundles, rather than a single bundle [Macdonald,C]
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
A statue and its matter have different persistence conditions, so they are not identical [Macdonald,C]
9. Objects / C. Structure of Objects / 7. Substratum
A substance is either a bundle of properties, or a bare substratum, or an essence [Macdonald,C]
Each substance contains a non-property, which is its substratum or bare particular [Macdonald,C]
The substratum theory explains the unity of substances, and their survival through change [Macdonald,C]
A substratum has the quality of being bare, and they are useless because indiscernible [Macdonald,C]
9. Objects / D. Essence of Objects / 14. Knowledge of Essences
Essence is the distinct thinkability of anything [Leibniz]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
An object is identical with itself, and no different indiscernible object can share that [Russell/Whitehead, by Adams,RM]
At different times Leibniz articulated three different versions of his so-called Law [Macdonald,C]
The Identity of Indiscernibles is false, because it is not necessarily true [Macdonald,C]
12. Knowledge Sources / E. Direct Knowledge / 2. Intuition
Russell showed, through the paradoxes, that our basic logical intuitions are self-contradictory [Russell/Whitehead, by Gödel]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
In continuity, what matters is not just the beginning and end states, but the process itself [Macdonald,C]
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
The multiple relations theory says assertions about propositions are about their ingredients [Russell/Whitehead, by Linsky,B]
A judgement is a complex entity, of mind and various objects [Russell/Whitehead]
The meaning of 'Socrates is human' is completed by a judgement [Russell/Whitehead]
The multiple relation theory of judgement couldn't explain the unity of sentences [Morris,M on Russell/Whitehead]
Only the act of judging completes the meaning of a statement [Russell/Whitehead]
19. Language / D. Propositions / 3. Concrete Propositions
Propositions as objects of judgement don't exist, because we judge several objects, not one [Russell/Whitehead]