Combining Texts

All the ideas for 'A Dictionary of Political Thought', 'The Justification of Deduction' and 'Model Theory'

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27 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / a. Philosophy as worldly
Philosophy aims to understand the world, through ordinary experience and science [Dummett]
2. Reason / D. Definition / 7. Contextual Definition
The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W]
2. Reason / E. Argument / 6. Conclusive Proof
A successful proof requires recognition of truth at every step [Dummett]
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Truth-tables are dubious in some cases, and may be a bad way to explain connective meaning [Dummett]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Deduction is justified by the semantics of its metalanguage [Dummett, by Hanna]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Since first-order languages are complete, |= and |- have the same meaning [Hodges,W]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Syntactic consequence is positive, for validity; semantic version is negative, with counterexamples [Dummett]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
|= in model-theory means 'logical consequence' - it holds in all models [Hodges,W]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
Beth trees show semantics for intuitionistic logic, in terms of how truth has been established [Dummett]
In standard views you could replace 'true' and 'false' with mere 0 and 1 [Dummett]
Classical two-valued semantics implies that meaning is grasped through truth-conditions [Dummett]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
|= should be read as 'is a model for' or 'satisfies' [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W]
Model theory studies formal or natural language-interpretation using set-theory [Hodges,W]
Models in model theory are structures, not sets of descriptions [Hodges,W]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Soundness and completeness proofs test the theory of meaning, rather than the logic theory [Dummett]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
First-order logic can't discriminate between one infinite cardinal and another [Hodges,W]
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
An explanation is often a deduction, but that may well beg the question [Dummett]
19. Language / A. Nature of Meaning / 10. Denial of Meanings
Holism is not a theory of meaning; it is the denial that a theory of meaning is possible [Dummett]
22. Metaethics / C. The Good / 1. Goodness / g. Consequentialism
Consequentialism emphasises value rather than obligation in morality [Scruton]
23. Ethics / C. Virtue Theory / 3. Virtues / h. Respect
Altruism is either emotional (where your interests are mine) or moral (where they are reasons for me) [Scruton]
24. Political Theory / A. Basis of a State / 3. Natural Values / c. Natural rights
The idea of a right seems fairly basic; justice may be the disposition to accord rights to people [Scruton]
24. Political Theory / D. Ideologies / 3. Conservatism
Allegiance is fundamental to the conservative view of society [Scruton]
24. Political Theory / D. Ideologies / 5. Democracy / f. Against democracy
Democrats are committed to a belief and to its opposite, if the majority prefer the latter [Scruton]
24. Political Theory / D. Ideologies / 6. Liberalism / a. Liberalism basics
Liberals focus on universal human freedom, natural rights, and tolerance [Scruton, by PG]
25. Social Practice / D. Justice / 2. The Law / d. Legal positivism
For positivists law is a matter of form, for naturalists it is a matter of content [Scruton]
25. Social Practice / F. Life Issues / 3. Abortion
The issue of abortion seems insoluble, because there is nothing with which to compare it [Scruton]