Combining Texts

All the ideas for 'The Bhagavad Gita', 'Boole calculus and the Concept script' and 'A Tour through Mathematical Logic'

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32 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Serene wisdom is freedom from ties, and indifference to fortune [Anon (Bhag)]
2. Reason / A. Nature of Reason / 7. Status of Reason
Seek salvation in the wisdom of reason [Anon (Bhag)]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
A 'tautology' must include connectives [Wolf,RS]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL
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 ∀
Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS]
Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / e. Existential quantifier ∃
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
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
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
In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS]
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 / J. Model Theory in Logic / 1. Logical Models
Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS]
Model theory reveals the structures of mathematics [Wolf,RS]
Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS]
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
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
The LST Theorem is a serious limitation of first-order logic [Wolf,RS]
5. Theory of Logic / K. Features of Logics / 4. Completeness
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
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
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
Modern mathematics has unified all of its objects within set theory [Wolf,RS]
8. Modes of Existence / D. Universals / 6. Platonic Forms / a. Platonic Forms
I am all the beauty and goodness of things, says Krishna [Anon (Bhag)]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / a. Consciousness
In all living beings I am the light of consciousness, says Krishna [Anon (Bhag)]
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
We don't judge by combining subject and concept; we get a concept by splitting up a judgement [Frege]
20. Action / A. Definition of Action / 1. Action Theory
All actions come from: body, lower self, perception, means of action, or Fate [Anon (Bhag)]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Hate and lust have their roots in man's lower nature [Anon (Bhag)]
25. Social Practice / E. Policies / 1. War / a. Just wars
There is no greater good for a warrior than to fight in a just war [Anon (Bhag)]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / f. Ancient elements
The visible forms of nature are earth, water, fire, air, ether; mind, reason, and the sense of 'I' [Anon (Bhag)]
28. God / A. Divine Nature / 1. God
Everything, including the gods, comes from me, says Krishna [Anon (Bhag)]
29. Religion / A. Polytheistic Religion / 3. Hinduism
Brahman is supreme, Atman his spirit in man, and Karma is the force of creation [Anon (Bhag)]
29. Religion / D. Religious Issues / 1. Religious Commitment / e. Fideism
Only by love can men see me, know me, and come to me, says Krishna [Anon (Bhag)]
29. Religion / D. Religious Issues / 2. Immortality / e. Hell
The three gates of hell are lust, anger and greed [Anon (Bhag)]