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All the ideas for 'What is Logic?st1=Ian Hacking', 'Croce and Collingwood' and 'Value Theory'

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29 ideas

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 / 5. Supervenience / a. Nature of supervenience
To avoid misunderstandings supervenience is often expressed negatively: no A-change without B-change [Orsi]
20. Action / C. Motives for Action / 3. Acting on Reason / c. Reasons as causes
Rather than requiring an action, a reason may 'entice' us, or be 'eligible', or 'justify' it [Orsi]
21. Aesthetics / A. Aesthetic Experience / 1. Aesthetics
By 1790 aestheticians were mainly trying to explain individual artistic genius [Kemp]
21. Aesthetics / B. Nature of Art / 4. Art as Expression
Expression can be either necessary for art, or sufficient for art (or even both) [Kemp]
We don't already know what to express, and then seek means of expressing it [Kemp]
The horror expressed in some works of art could equallly be expressed by other means [Kemp]
22. Metaethics / B. Value / 1. Nature of Value / a. Nature of value
Value-maker concepts (such as courageous or elegant) simultaneously describe and evaluate [Orsi]
Final value is favoured for its own sake, and personal value for someone's sake [Orsi]
The '-able' concepts (like enviable) say this thing deserves a particular response [Orsi]
Things are only valuable if something makes it valuable, and we can ask for the reason [Orsi]
A complex value is not just the sum of the values of the parts [Orsi]
Trichotomy Thesis: comparable values must be better, worse or the same [Orsi]
The Fitting Attitude view says values are fitting or reasonable, and values are just byproducts [Orsi]
22. Metaethics / B. Value / 1. Nature of Value / c. Objective value
Values from reasons has the 'wrong kind of reason' problem - admiration arising from fear [Orsi]
22. Metaethics / B. Value / 1. Nature of Value / f. Ultimate value
A thing may have final value, which is still derived from other values, or from relations [Orsi]
22. Metaethics / B. Value / 2. Values / a. Normativity
Values can be normative in the Fitting Attitude account, where 'good' means fitting favouring [Orsi]
The Buck-Passing view of normative values says other properties are reasons for the value [Orsi]
Truths about value entail normative truths about actions or attitudes [Orsi]