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All the ideas for 'What is Logic?st1=Ian Hacking', 'Causality: Production and Propagation' and 'Ordinatio'

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22 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]
8. Modes of Existence / B. Properties / 1. Nature of Properties
16648 Accidents must have formal being, if they are principles of real action, and of mental action and thought [Duns Scotus]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
15386 If only the singular exists, science is impossible, as that relies on true generalities [Duns Scotus, by Panaccio]
15387 If things were singular they would only differ numerically, but horse and tulip differ more than that [Duns Scotus, by Panaccio]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
16632 We distinguish one thing from another by contradiction, because this is, and that is not [Duns Scotus]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
13094 The haecceity is the featureless thing which gives ultimate individuality to a substance [Duns Scotus, by Cover/O'Leary-Hawthorne]
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
16770 It is absurd that there is no difference between a genuinely unified thing, and a mere aggregate [Duns Scotus]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
10919 What prevents a stone from being divided into parts which are still the stone? [Duns Scotus]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
16768 Two things are different if something is true of one and not of the other [Duns Scotus]
26. Natural Theory / C. Causation / 4. Naturalised causation
8412 A causal interaction is when two processes intersect, and correlated modifications persist afterwards [Salmon]
26. Natural Theory / C. Causation / 5. Direction of causation
8413 Cause must come first in propagations of causal interactions, but interactions are simultaneous [Salmon]
26. Natural Theory / C. Causation / 8. Particular Causation / b. Causal relata
8411 Instead of localised events, I take enduring and extended processes as basic to causation [Salmon]