Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'Introduction - Ontology' and 'Anthropological Studies of Classification'

expand these ideas     |    start again     |     specify just one area for these texts

20 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
13833 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
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]
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 / C. Structure of Existence / 3. Levels of Reality
5500 Biologists see many organic levels, 'abstract' if seen from below, 'structural' if seen from above [Lycan]
7. Existence / E. Categories / 1. Categories
10496 Monothetic categories have fixed defining features, and polythetic categories do not [Ellen]
10497 In symbolic classification, the categories are linked to rules [Ellen]
7. Existence / E. Categories / 5. Category Anti-Realism
10495 Continuous experience sometimes needs imposition of boundaries to create categories [Ellen]
9. Objects / F. Identity among Objects / 6. Identity between Objects
5494 'Lightning is electric discharge' and 'Phosphorus is Venus' are synthetic a posteriori identities [Lycan]
13. Knowledge Criteria / E. Relativism / 4. Cultural relativism
10498 Classification is no longer held to be rooted in social institutions [Ellen]
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
5496 Functionalism has three linked levels: physical, functional, and mental [Lycan]
17. Mind and Body / C. Functionalism / 5. Teleological Functionalism
5499 A mental state is a functional realisation of a brain state when it serves the purpose of the organism [Lycan]
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / c. Purpose denied
5501 People are trying to explain biological teleology in naturalistic causal terms [Lycan]