Combining Philosophers

All the ideas for Alex Orenstein, Keith Devlin and Richard Jeffrey

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29 ideas

1. Philosophy / B. History of Ideas / 5. Later European Thought
8092 Logic was merely a branch of rhetoric until the scientific 17th century [Devlin]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
8081 'No councillors are bankers' and 'All bankers are athletes' implies 'Some athletes are not councillors' [Devlin]
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
8085 Modern propositional inference replaces Aristotle's 19 syllogisms with modus ponens [Devlin]
8472 Sentential logic is consistent (no contradictions) and complete (entirely provable) [Orenstein]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
8086 Predicate logic retains the axioms of propositional logic [Devlin]
8476 Axiomatization simply picks from among the true sentences a few to play a special role [Orenstein]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
8480 S4: 'poss that poss that p' implies 'poss that p'; S5: 'poss that nec that p' implies 'nec that p' [Orenstein]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
8474 Unlike elementary logic, set theory is not complete [Orenstein]
4. Formal Logic / G. Formal Mereology / 1. Mereology
8465 Mereology has been exploited by some nominalists to achieve the effects of set theory [Orenstein]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
8091 Situation theory is logic that takes account of context [Devlin]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
8087 Golden ages: 1900-1960 for pure logic, and 1950-1985 for applied logic [Devlin]
8089 Montague's intensional logic incorporated the notion of meaning [Devlin]
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
8082 Where a conditional is purely formal, an implication implies a link between premise and conclusion [Devlin]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
8072 Sentences of apparent identical form can have different contextual meanings [Devlin]
5. Theory of Logic / G. Quantification / 1. Quantification
8452 Traditionally, universal sentences had existential import, but were later treated as conditional claims [Orenstein]
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
8475 The substitution view of quantification says a sentence is true when there is a substitution instance [Orenstein]
5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / a. Achilles paradox
8075 Space and time are atomic in the arrow, and divisible in the tortoise [Devlin]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
8454 The whole numbers are 'natural'; 'rational' numbers include fractions; the 'reals' include root-2 etc. [Orenstein]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
8473 The logicists held that is-a-member-of is a logical constant, making set theory part of logic [Orenstein]
7. Existence / E. Categories / 3. Proposed Categories
8458 Just individuals in Nominalism; add sets for Extensionalism; add properties, concepts etc for Intensionalism [Orenstein]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / b. Worlds as fictions
16285 A possible world can be seen as a complete and consistent novel [Jeffrey]
13. Knowledge Criteria / E. Relativism / 5. Language Relativism
8088 People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin]
14. Science / B. Scientific Theories / 1. Scientific Theory
8457 The Principle of Conservatism says we should violate the minimum number of background beliefs [Orenstein]
14. Science / C. Induction / 6. Bayes's Theorem
19155 Instead of gambling, Jeffrey made the objects of Bayesian preference to be propositions [Jeffrey, by Davidson]
19. Language / A. Nature of Meaning / 10. Denial of Meanings
8477 People presume meanings exist because they confuse meaning and reference [Orenstein]
19. Language / C. Assigning Meanings / 1. Syntax
8073 How do we parse 'time flies like an arrow' and 'fruit flies like an apple'? [Devlin]
19. Language / C. Assigning Meanings / 3. Predicates
8471 Three ways for 'Socrates is human' to be true are nominalist, platonist, or Montague's way [Orenstein]
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
8076 The distinction between sentences and abstract propositions is crucial in logic [Devlin]
19. Language / D. Propositions / 4. Mental Propositions
8484 If two people believe the same proposition, this implies the existence of propositions [Orenstein]