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All the ideas for 'What is Logic?st1=Ian Hacking', 'talk' and 'Convergence'

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23 ideas

2. Reason / D. Definition / 3. Types of Definition
13838 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
13834 Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
13835 Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
13833 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
13845 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
13840 First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
13844 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
13842 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
13837 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
13839 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
13843 If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
15. Nature of Minds / C. Capacities of Minds / 1. Faculties
20657 There are 23 core brain functions, with known circuit, transmitters, genes and behaviour [Watson]
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
20656 Traditional ideas of the mind were weakened in the 1950s by mind-influencing drugs [Watson]
17. Mind and Body / E. Mind as Physical / 2. Reduction of Mind
4688 We imagine small and large objects scaled to the same size, suggesting a fixed capacity for imagination [Lavers]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
20655 Humans have been hunter-gatherers for 99.5% of their existence [Watson]
26. Natural Theory / C. Causation / 7. Eliminating causation
20650 The Uncertainty Principle implies that cause and effect can't be measured [Watson]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / a. Electrodynamics
20649 The interference of light through two slits confirmed that it is waves [Watson]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / c. Electrons
20661 Electrons rotate in hyrogen atoms 10^13 times per second [Watson]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / d. Quantum mechanics
20647 Quantum theory explains why nature is made up of units, such as elements [Watson]
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
20654 Only four particles are needed for matter: up and down quark, electron, electron-neutrino [Watson]
27. Natural Reality / F. Chemistry / 1. Chemistry
20651 The shape of molecules is important, as well as the atoms and their bonds [Watson]
27. Natural Reality / G. Biology / 2. Life
20652 In 1828 the animal substance urea was manufactured from inorganic ingredients [Watson]
20658 Information is physical, and living can be seen as replicating and preserving information [Watson]