Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'On the Pragmatics of Communications' and 'New work for a theory of universals'

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45 ideas

1. Philosophy / F. Analytic Philosophy / 4. Conceptual Analysis
In addition to analysis of a concept, one can deny it, or accept it as primitive [Lewis]
2. Reason / D. Definition / 3. Types of Definition
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
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]
'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
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]
7. Existence / C. Structure of Existence / 2. Reduction
Supervenience is reduction without existence denials, ontological priorities, or translatability [Lewis]
7. Existence / C. Structure of Existence / 5. Supervenience / c. Significance of supervenience
A supervenience thesis is a denial of independent variation [Lewis]
7. Existence / D. Theories of Reality / 6. Physicalism
Materialism is (roughly) that two worlds cannot differ without differing physically [Lewis]
8. Modes of Existence / B. Properties / 1. Nature of Properties
Universals are wholly present in their instances, whereas properties are spread around [Lewis]
8. Modes of Existence / B. Properties / 5. Natural Properties
Natural properties figure in the analysis of similarity in intrinsic respects [Lewis, by Oliver]
Lewisian natural properties fix reference of predicates, through a principle of charity [Lewis, by Hawley]
Reference partly concerns thought and language, partly eligibility of referent by natural properties [Lewis]
Objects are demarcated by density and chemistry, and natural properties belong in what is well demarcated [Lewis]
Natural properties tend to belong to well-demarcated things, typically loci of causal chains [Lewis]
For us, a property being natural is just an aspect of its featuring in the contents of our attitudes [Lewis]
All perfectly natural properties are intrinsic [Lewis, by Lewis]
Natural properties fix resemblance and powers, and are picked out by universals [Lewis]
8. Modes of Existence / B. Properties / 6. Categorical Properties
Lewis says properties are sets of actual and possible objects [Lewis, by Heil]
Any class of things is a property, no matter how whimsical or irrelevant [Lewis]
8. Modes of Existence / B. Properties / 10. Properties as Predicates
There are far more properties than any brain could ever encodify [Lewis]
We need properties as semantic values for linguistic expressions [Lewis]
8. Modes of Existence / B. Properties / 11. Properties as Sets
Properties are classes of possible and actual concrete particulars [Lewis, by Koslicki]
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
Lewisian properties have powers because of their relationships to other properties [Lewis, by Hawthorne]
8. Modes of Existence / C. Powers and Dispositions / 7. Against Powers
Most properties are causally irrelevant, and we can't spot the relevant ones. [Lewis]
8. Modes of Existence / D. Universals / 1. Universals
I suspend judgements about universals, but their work must be done [Lewis]
8. Modes of Existence / D. Universals / 2. Need for Universals
Physics aims to discover which universals actually exist [Lewis, by Moore,AW]
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
The One over Many problem (in predication terms) deserves to be neglected (by ostriches) [Lewis]
8. Modes of Existence / E. Nominalism / 5. Class Nominalism
To have a property is to be a member of a class, usually a class of things [Lewis]
Class Nominalism and Resemblance Nominalism are pretty much the same [Lewis]
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
Psychophysical identity implies the possibility of idealism or panpsychism [Lewis]
19. Language / A. Nature of Meaning / 6. Meaning as Use
To understand language is to know how to use it to reach shared understandings [Habermas]
19. Language / F. Communication / 6. Interpreting Language / c. Principle of charity
We need natural properties in order to motivate the principle of charity [Lewis]
A sophisticated principle of charity sometimes imputes error as well as truth [Lewis]
26. Natural Theory / C. Causation / 9. General Causation / c. Counterfactual causation
Counterfactuals 'backtrack' if a different present implies a different past [Lewis]
Causal counterfactuals must avoid backtracking, to avoid epiphenomena and preemption [Lewis]
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
Physics aims for a list of natural properties [Lewis]
Physics discovers laws and causal explanations, and also the natural properties required [Lewis]
26. Natural Theory / D. Laws of Nature / 4. Regularities / b. Best system theory
A law of nature is any regularity that earns inclusion in the ideal system [Lewis]