Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'MacIntyre versus the Enlightenment' and 'Either/Or: a fragment of life'

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21 ideas

1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
22087 Philosophy fails to articulate the continual becoming of existence [Kierkegaard, by Carlisle]
2. Reason / D. Definition / 3. Types of Definition
13838 A decent modern definition should always imply a semantics [Hacking]
3. Truth / A. Truth Problems / 8. Subjective Truth
5651 Traditional views of truth are tautologies, and truth is empty without a subject [Kierkegaard, by Scruton]
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]
13. Knowledge Criteria / E. Relativism / 4. Cultural relativism
1490 You would have to be very morally lazy to ignore criticisms of your own culture [Nagel]
23. Ethics / F. Existentialism / 2. Nihilism
22090 For me time stands still, and I with it [Kierkegaard, by Carlisle]
23. Ethics / F. Existentialism / 4. Boredom
9305 The plebeians bore others; only the nobility bore themselves [Kierkegaard]
23. Ethics / F. Existentialism / 5. Existence-Essence
5650 Reason is just abstractions, so our essence needs a subjective 'leap of faith' [Kierkegaard, by Scruton]
23. Ethics / F. Existentialism / 6. Authentic Self
22095 There are aesthetic, ethical and religious subjectivity [Kierkegaard, by Carlisle]
23. Ethics / F. Existentialism / 7. Existential Action
20747 What matters is not right choice, but energy, earnestness and pathos in the choosing [Kierkegaard]
24. Political Theory / D. Ideologies / 7. Communitarianism / b. Against communitarianism
22091 Kierkegaard prioritises the inward individual, rather than community [Kierkegaard, by Carlisle]
29. Religion / D. Religious Issues / 1. Religious Commitment / e. Fideism
22088 Faith is like a dancer's leap, going up to God, but also back to earth [Kierkegaard, by Carlisle]