Combining Texts

All the ideas for 'The Science of Knowing (Wissenschaftslehre) [1st ed]', 'The Psychophysical Nexus' and 'A Tour through Mathematical Logic'

expand these ideas     |    start again     |     specify just one area for these texts

33 ideas

2. Reason / A. Nature of Reason / 5. Objectivity
22024 Fichte's subjectivity struggles to then give any account of objectivity [Pinkard on Fichte]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
13520 A 'tautology' must include connectives [Wolf,RS]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL
13524 Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / d. Universal quantifier ∀
13522 Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS]
13521 Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / e. Existential quantifier ∃
13523 Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / e. Axiom of the Empty Set IV
13529 Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / n. Axiom of Comprehension
13526 Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
13534 In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS]
13535 First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not
22017 Normativity needs the possibility of negation, in affirmation and denial [Fichte, by Pinkard]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
13531 Model theory reveals the structures of mathematics [Wolf,RS]
13532 Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS]
13519 Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS]
13533 First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
13537 An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
13539 The LST Theorem is a serious limitation of first-order logic [Wolf,RS]
5. Theory of Logic / K. Features of Logics / 4. Completeness
13538 If a theory is complete, only a more powerful language can strengthen it [Wolf,RS]
5. Theory of Logic / K. Features of Logics / 10. Monotonicity
13525 Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
13530 An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
13518 Modern mathematics has unified all of its objects within set theory [Wolf,RS]
7. Existence / C. Structure of Existence / 5. Supervenience / c. Significance of supervenience
4242 Pure supervenience explains nothing, and is a sign of something fundamental we don't know [Nagel]
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
22018 Necessary truths derive from basic assertion and negation [Fichte, by Pinkard]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / b. Transcendental idealism
22064 Fichte's logic is much too narrow, and doesn't deduce ethics, art, society or life [Schlegel,F on Fichte]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / d. Absolute idealism
22032 Fichte's key claim was that the subjective-objective distinction must itself be subjective [Fichte, by Pinkard]
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / a. Other minds
22020 We only see ourselves as self-conscious and rational in relation to other rationalities [Fichte]
16. Persons / B. Nature of the Self / 4. Presupposition of Self
22060 The Self is the spontaneity, self-relatedness and unity needed for knowledge [Fichte, by Siep]
22066 Novalis sought a much wider concept of the ego than Fichte's proposal [Novalis on Fichte]
22016 The self is not a 'thing', but what emerges from an assertion of normativity [Fichte, by Pinkard]
16. Persons / B. Nature of the Self / 6. Self as Higher Awareness
22019 Consciousness of an object always entails awareness of the self [Fichte]
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
22061 Judgement is distinguishing concepts, and seeing their relations [Fichte, by Siep]
22. Metaethics / B. Value / 1. Nature of Value / d. Subjective value
22023 Fichte's idea of spontaneity implied that nothing counts unless we give it status [Fichte, by Pinkard]
26. Natural Theory / A. Speculations on Nature / 1. Nature
22065 Fichte reduces nature to a lifeless immobility [Schlegel,F on Fichte]