Combining Texts

All the ideas for 'Confessions', 'Letters to Queen Charlotte' and 'Principia Mathematica'

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53 ideas

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 / 4. Axioms for Number / a. Axioms for numbers
We know mathematical axioms, such as subtracting equals from equals leaves equals, by a natural light [Leibniz]
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 / A. Nature of Existence / 2. Types of Existence
I prefer a lack of form to mean non-existence, than to think of some quasi-existence [Augustine]
7. Existence / D. Theories of Reality / 1. Ontologies
Three main questions seem to be whether a thing is, what it is, and what sort it is [Augustine]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
A necessary feature (such as air for humans) is not therefore part of the essence [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]
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
Intelligible truth is independent of any external things or experiences [Leibniz]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / d. Secondary qualities
We know objects by perceptions, but their qualities don't reveal what it is we are perceiving [Leibniz]
12. Knowledge Sources / D. Empiricism / 1. Empiricism
There is nothing in the understanding but experiences, plus the understanding itself, and the understander [Leibniz]
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]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
Mind and memory are the same, as shown in 'bear it in mind' or 'it slipped from mind' [Augustine]
Memory contains innumerable principles of maths, as well as past sense experiences [Augustine]
We would avoid remembering sorrow or fear if that triggered the emotions afresh [Augustine]
I can distinguish different smells even when I am not experiencing them [Augustine]
Why does joy in my mind make me happy, but joy in my memory doesn't? [Augustine]
15. Nature of Minds / A. Nature of Mind / 6. Anti-Individualism
Memory is so vast that I cannot recognise it as part of my mind [Augustine]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / a. Memory is Self
Without memory I could not even speak of myself [Augustine]
16. Persons / F. Free Will / 6. Determinism / a. Determinism
If the future does not exist, how can prophets see it? [Augustine]
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]
18. Thought / B. Mechanics of Thought / 5. Mental Files
Memories are preserved separately, according to category [Augustine]
19. Language / D. Propositions / 3. Concrete Propositions
Propositions as objects of judgement don't exist, because we judge several objects, not one [Russell/Whitehead]
22. Metaethics / C. The Good / 2. Happiness / c. Value of happiness
Everyone wants happiness [Augustine]
27. Natural Reality / D. Time / 1. Nature of Time / c. Idealist time
Maybe time is an extension of the mind [Augustine]
To be aware of time it can only exist in the mind, as memory or anticipation [Augustine, by Bardon]
27. Natural Reality / D. Time / 1. Nature of Time / g. Growing block
How can ten days ahead be a short time, if it doesn't exist? [Augustine]
27. Natural Reality / D. Time / 1. Nature of Time / h. Presentism
If the past is no longer, and the future is not yet, how can they exist? [Augustine]
27. Natural Reality / D. Time / 1. Nature of Time / i. Denying time
The whole of the current year is not present, so how can it exist? [Augustine]
27. Natural Reality / D. Time / 2. Passage of Time / a. Experience of time
I know what time is, until someone asks me to explain it [Augustine]
27. Natural Reality / D. Time / 2. Passage of Time / h. Change in time
I disagree with the idea that time is nothing but cosmic movement [Augustine]
27. Natural Reality / E. Cosmology / 3. The Beginning
Heaven and earth must be created, because they are subject to change [Augustine]
28. God / A. Divine Nature / 5. God and Time
If God existed before creation, why would a perfect being desire to change things? [Augustine, by Bardon]
If God is outside time in eternity, can He hear prayers? [Augustine]