Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'Oxford Dictionary of Philosophy' and 'Relations'

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

22 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]
8. Modes of Existence / A. Relations / 1. Nature of Relations
21339 We want the ontology of relations, not just a formal way of specifying them [Heil]
21349 Two people are indirectly related by height; the direct relation is internal, between properties [Heil]
21340 Maybe all the other features of the world can be reduced to relations [Heil]
8. Modes of Existence / A. Relations / 2. Internal Relations
21348 In the case of 5 and 6, their relational truthmaker is just the numbers [Heil]
21351 Truthmaking is a clear example of an internal relation [Heil]
21344 If R internally relates a and b, and you have a and b, you thereby have R [Heil]
8. Modes of Existence / C. Powers and Dispositions / 4. Powers as Essence
21350 If properties are powers, then causal relations are internal relations [Heil]
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
6451 Visual sense data are an inner picture show which represents the world [Blackburn]
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / b. Anti-reliabilism
2866 A true belief might be based on a generally reliable process that failed on this occasion [Blackburn]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
2864 The main objection to intuitionism in ethics is that intuition is a disguise for prejudice or emotion [Blackburn]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / i. Prescriptivism
2865 Critics of prescriptivism observe that it is consistent to accept an ethical verdict but refuse to be bound by it [Blackburn]