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All the ideas for 'What is Logic?st1=Ian Hacking', 'Physics and Philosophy' and 'comedies (frags)'

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35 ideas

2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
The various logics are abstractions made from terms like 'if...then' in English [Hacking]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order completeness seems to need intensional entities and possible worlds [Hacking]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
If it can't be expressed mathematically, it can't occur in nature? [Heisenberg]
7. Existence / D. Theories of Reality / 2. Realism
Quantum theory shows that exact science does not need dogmatic realism [Heisenberg]
7. Existence / D. Theories of Reality / 4. Anti-realism
Quantum theory does not introduce minds into atomic events [Heisenberg]
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
A 'probability wave' is a quantitative version of Aristotle's potential, a mid-way type of reality [Heisenberg]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
We can retain the idea of 'substance', as indestructible mass or energy [Heisenberg]
9. Objects / C. Structure of Objects / 2. Hylomorphism / b. Form as principle
Basic particles have a mathematical form, which is more important than their substance [Heisenberg]
9. Objects / C. Structure of Objects / 6. Constitution of an Object
Additional or removal of any part changes a thing, so people are never the same person [Epicharmus]
13. Knowledge Criteria / E. Relativism / 1. Relativism
A dog seems handsome to another a dog, and even a pig to another pig [Epicharmus]
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
We give a mathematical account of a system of natural connections in order to clarify them [Heisenberg]
22. Metaethics / C. The Good / 3. Pleasure / f. Dangers of pleasure
Pleasures are like pirates - if you are caught they drown you in a sea of pleasures [Epicharmus]
23. Ethics / B. Contract Ethics / 1. Contractarianism
Hands wash hands; give that you may get [Epicharmus]
23. Ethics / C. Virtue Theory / 3. Virtues / c. Justice
Against a villain, villainy is not a useless weapon [Epicharmus]
26. Natural Theory / D. Laws of Nature / 2. Types of Laws
Seven theories in science: mechanics, heat, electricity, quantum, particles, relativity, life [Heisenberg, by PG]
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / a. Energy
Energy is that which moves, and is the substance from which everything is made [Heisenberg]
Energy is an unchanging substance, having many forms, and causing all change [Heisenberg]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / b. Fields
Maxwell introduced real fields, which transferred forces from point to point [Heisenberg]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / d. Quantum mechanics
Radiation interference needs waves, but radiation photoelectric effects needs particles [Heisenberg]
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
An atom's stability after collisions needs explaining (which Newton's mechanics can't do) [Heisenberg]
Position is complementary to velocity or momentum, so the whole system is indeterminate [Heisenberg]
It was formerly assumed that electromagnetic waves could not be a reality in themselves [Heisenberg]
27. Natural Reality / C. Space / 4. Substantival Space
So-called 'empty' space is the carrier of geometry and kinematics [Heisenberg]
27. Natural Reality / D. Time / 3. Parts of Time / e. Present moment
In relativity the length of the 'present moment' is relative to distance from the observer [Heisenberg]
28. God / A. Divine Nature / 3. Divine Perfections
God knows everything, and nothing is impossible for him [Epicharmus]
29. Religion / D. Religious Issues / 3. Problem of Evil / c. Human Error
Human logos is an aspect of divine logos, and is sufficient for successful living [Epicharmus]