Combining Texts

All the ideas for 'Cratylus', 'Principia Mathematica' and 'Truth'

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49 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Wisdom is called 'beautiful', because it performs fine works [Plato]
1. Philosophy / A. Wisdom / 2. Wise People
Good people are no different from wise ones [Plato]
2. Reason / C. Styles of Reason / 1. Dialectic
A dialectician is someone who knows how to ask and to answer questions [Plato]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Truths say of what is that it is, falsehoods say of what is that it is not [Plato]
3. Truth / C. Correspondence Truth / 2. Correspondence to Facts
The fact which is stated by a true sentence is not something in the world [Strawson,P]
Facts aren't exactly true statements, but they are what those statements say [Strawson,P]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
The statement that it is raining perfectly fits the fact that it is raining [Strawson,P]
3. Truth / F. Semantic Truth / 2. Semantic Truth
The word 'true' always refers to a possible statement [Strawson,P]
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]
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
A name is a sort of tool [Plato]
A name-giver might misname something, then force other names to conform to it [Plato]
Things must be known before they are named, so it can't be the names that give us knowledge [Plato]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
Anyone who knows a thing's name also knows the thing [Plato]
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 took arithmetic to be higher-order logic [Russell/Whitehead, by Hodes]
Russell and Whitehead were not realists, but embraced nearly all of maths in logic [Russell/Whitehead, by Friend]
'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 / B. Change in Existence / 1. Nature of Change
How can beauty have identity if it changes? [Plato]
7. Existence / E. Categories / 2. Categorisation
We only succeed in cutting if we use appropriate tools, not if we approach it randomly [Plato]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
Doesn't each thing have an essence, just as it has other qualities? [Plato]
9. Objects / D. Essence of Objects / 3. Individual Essences
Things don't have every attribute, and essence isn't private, so each thing has an essence [Plato]
9. Objects / D. Essence of Objects / 15. Against Essentialism
Is the being or essence of each thing private to each person? [Plato]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
If we made a perfect duplicate of Cratylus, there would be two Cratyluses [Plato]
An object is identical with itself, and no different indiscernible object can share that [Russell/Whitehead, by Adams,RM]
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]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
There can't be any knowledge if things are constantly changing [Plato]
15. Nature of Minds / A. Nature of Mind / 2. Psuche
Soul causes the body to live, and gives it power to breathe and to be revitalized [Plato]
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]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / a. Nature of virtue
'Arete' signifies lack of complexity and a free-flowing soul [Plato]
27. Natural Reality / G. Biology / 5. Species
The natural offspring of a lion is called a 'lion' (but what about the offspring of a king?) [Plato]
28. God / A. Divine Nature / 2. Divine Nature
Even the gods love play [Plato]