Combining Texts

All the ideas for 'fragments/reports', 'On Second-Order Logic' and 'Logical Atomism'

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23 ideas

1. Philosophy / F. Analytic Philosophy / 1. Nature of Analysis
Philosophy is logical analysis, followed by synthesis [Russell]
1. Philosophy / F. Analytic Philosophy / 6. Logical Analysis
A logical language would show up the fallacy of inferring reality from ordinary language [Russell]
1. Philosophy / G. Scientific Philosophy / 3. Scientism
Philosophy should be built on science, to reduce error [Russell]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Subject-predicate logic (and substance-attribute metaphysics) arise from Aryan languages [Russell]
5. Theory of Logic / A. Overview of Logic / 3. Value of Logic
It is logic, not metaphysics, that is fundamental to philosophy [Russell]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley]
Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Vagueness, and simples being beyond experience, are obstacles to a logical language [Russell]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
'∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Some axioms may only become accepted when they lead to obvious conclusions [Russell]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Why should compactness be definitive of logic? [Boolos, by Hacking]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Many concepts can only be expressed by second-order logic [Boolos]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
Maths can be deduced from logical axioms and the logic of relations [Russell]
7. Existence / C. Structure of Existence / 6. Fundamentals / d. Logical atoms
Russell gave up logical atomism because of negative, general and belief propositions [Russell, by Read]
To mean facts we assert them; to mean simples we name them [Russell]
'Simples' are not experienced, but are inferred at the limits of analysis [Russell]
Better to construct from what is known, than to infer what is unknown [Russell]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
As propositions can be put in subject-predicate form, we wrongly infer that facts have substance-quality form [Russell]
19. Language / A. Nature of Meaning / 1. Meaning
Meaning takes many different forms, depending on different logical types [Russell]
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]
27. Natural Reality / G. Biology / 3. Evolution
Archelaus said life began in a primeval slime [Archelaus, by Schofield]