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All the ideas for 'What is Logic?st1=Ian Hacking', 'fragments/reports' and 'Reasons for Actions and Desires'

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20 ideas

1. Philosophy / C. History of Philosophy / 2. Ancient Philosophy / b. Pre-Socratic philosophy
5988 Anaximander produced the first philosophy book (and maybe the first book) [Anaximander, by Bodnár]
2. Reason / B. Laws of Thought / 2. Sufficient Reason
1496 The earth is stationary, because it is in the centre, and has no more reason to move one way than another [Anaximander, by Aristotle]
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]
7. Existence / A. Nature of Existence / 1. Nature of Existence
14874 Anaximander saw the contradiction in the world - that its own qualities destroy it [Anaximander, by Nietzsche]
20. Action / C. Motives for Action / 3. Acting on Reason / b. Intellectualism
22393 I don't understand the idea of a reason for acting, but it is probably the agent's interests or desires [Foot]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / d. The unlimited
13222 The Boundless cannot exist on its own, and must have something contrary to it [Aristotle on Anaximander]
1495 Anaximander introduced the idea that the first principle and element of things was the Boundless [Anaximander, by Simplicius]
404 Things begin and end in the Unlimited, and are balanced over time according to justice [Anaximander]
405 The essential nature, whatever it is, of the non-limited is everlasting and ageless [Anaximander]
27. Natural Reality / E. Cosmology / 2. Eternal Universe
1746 The parts of all things are susceptible to change, but the whole is unchangeable [Anaximander, by Diog. Laertius]