Combining Philosophers

All the ideas for Horsten,L/Pettigrew,R, Gorgias and Alex Orenstein

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26 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
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
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 / 9. Philosophical Logic
18739 Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
18741 Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew]
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 / J. Model Theory in Logic / 1. Logical Models
18744 Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew]
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 / A. Nature of Existence / 1. Nature of Existence
18740 If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew]
7. Existence / A. Nature of Existence / 3. Being / d. Non-being
18933 Not-Being obviously doesn't exist, and the five modes of Being are all impossible [Gorgias, by Diog. Laertius]
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 / 1. Possible Worlds / a. Possible worlds
18745 A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew]
18747 The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew]
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
18748 Epistemic logic introduced impossible worlds [Horsten/Pettigrew]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
18746 Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew]
18750 Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew]
14. Science / B. Scientific Theories / 1. Scientific Theory
8457 The Principle of Conservatism says we should violate the minimum number of background beliefs [Orenstein]
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 / 3. Predicates
8471 Three ways for 'Socrates is human' to be true are nominalist, platonist, or Montague's way [Orenstein]
19. Language / D. Propositions / 4. Mental Propositions
8484 If two people believe the same proposition, this implies the existence of propositions [Orenstein]
19. Language / F. Communication / 1. Rhetoric
5864 Destroy seriousness with laughter, and laughter with seriousness [Gorgias]
9866 Gorgias says rhetoric is the best of arts, because it enslaves without using force [Gorgias, by Plato]