Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'Causality: Production and Propagation' and 'Five Milestones of Empiricism'

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


19 ideas

2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
2. Reason / D. Definition / 7. Contextual Definition
Contextual definition shifted the emphasis from words to whole sentences [Quine]
Bentham's contextual definitions preserved terms after their denotation became doubtful [Quine]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
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
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
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
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
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
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
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
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
12. Knowledge Sources / D. Empiricism / 1. Empiricism
In scientific theories sentences are too brief to be independent vehicles of empirical meaning [Quine]
Empiricism improvements: words for ideas, then sentences, then systems, then no analytic, then naturalism [Quine]
19. Language / E. Analyticity / 4. Analytic/Synthetic Critique
Holism in language blurs empirical synthetic and empty analytic sentences [Quine]
26. Natural Theory / C. Causation / 4. Naturalised causation
A causal interaction is when two processes intersect, and correlated modifications persist afterwards [Salmon]
26. Natural Theory / C. Causation / 5. Direction of causation
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
Instead of localised events, I take enduring and extended processes as basic to causation [Salmon]