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All the ideas for '', 'Principles of Philosophy' and 'Principia Mathematica'

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53 ideas

1. Philosophy / D. Nature of Philosophy / 2. Invocation to Philosophy
The greatest good for a state is true philosophers [Descartes]
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 / A. Overview of Logic / 1. Overview of Logic
If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt]
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 / 2. Logical Connectives / a. Logical connectives
The sense of a connective comes from primitively obvious rules of inference [Rumfitt]
Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt]
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 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]
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
All powers can be explained by obvious features like size, shape and motion of matter [Descartes]
8. Modes of Existence / D. Universals / 1. Universals
Five universals: genus, species, difference, property, accident [Descartes]
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
A universal is a single idea applied to individual things that are similar to one another [Descartes]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
If we perceive an attribute, we infer the existence of some substance [Descartes]
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
A substance needs nothing else in order to exist [Descartes]
9. Objects / D. Essence of Objects / 9. Essence and Properties
A substance has one principal property which is its nature and essence [Descartes]
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]
11. Knowledge Aims / B. Certain Knowledge / 4. The Cogito
Total doubt can't include your existence while doubting [Descartes]
I think, therefore I am, because for a thinking thing to not exist is a contradiction [Descartes]
'Thought' is all our conscious awareness, including feeling as well as understanding [Descartes]
12. Knowledge Sources / A. A Priori Knowledge / 4. A Priori as Necessities
'Nothing comes from nothing' is an eternal truth found within the mind [Descartes]
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 / B. Internal Justification / 4. Foundationalism / b. Basic beliefs
We can know basic Principles without further knowledge, but not the other way round [Descartes]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / b. Essence of consciousness
We can understand thinking occuring without imagination or sensation [Descartes]
16. Persons / D. Continuity of the Self / 7. Self and Thinking
In thinking we shut ourselves off from other substances, showing our identity and separateness [Descartes]
16. Persons / F. Free Will / 1. Nature of Free Will
Our free will is so self-evident to us that it must be a basic innate idea [Descartes]
17. Mind and Body / A. Mind-Body Dualism / 1. Dualism
There are two ultimate classes of existence: thinking substance and extended substance [Descartes]
17. Mind and Body / D. Property Dualism / 5. Supervenience of mind
Even if tightly united, mind and body are different, as God could separate them [Descartes]
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 / A. Modes of Thought / 6. Judgement / b. Error
Most errors of judgement result from an inaccurate perception of the facts [Descartes]
19. Language / D. Propositions / 3. Concrete Propositions
Propositions as objects of judgement don't exist, because we judge several objects, not one [Russell/Whitehead]
19. Language / F. Communication / 3. Denial
We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt]
20. Action / C. Motives for Action / 4. Responsibility for Actions
We do not praise the acts of an efficient automaton, as their acts are necessary [Descartes]
The greatest perfection of man is to act by free will, and thus merit praise or blame [Descartes]
26. Natural Theory / A. Speculations on Nature / 1. Nature
Physics only needs geometry or abstract mathematics, which can explain and demonstrate everything [Descartes]
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / c. Purpose denied
We will not try to understand natural or divine ends, or final causes [Descartes]
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / c. Matter as extension
Matter is not hard, heavy or coloured, but merely extended in space [Descartes]