19 ideas
8250 | So-called 'free logic' operates without existence assumptions [Meinong, by George/Van Evra] |
10147 | The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman] |
10148 | Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman] |
10149 | Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman] |
10150 | The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman] |
10146 | Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman] |
10158 | A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman] |
10162 | Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman] |
10159 | Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman] |
10160 | Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman] |
10161 | If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman] |
10156 | 'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman] |
10155 | Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman] |
8719 | There can be impossible and contradictory objects, if they can have properties [Meinong, by Friend] |
8971 | There are objects of which it is true that there are no such objects [Meinong] |
8718 | Meinong says an object need not exist, but must only have properties [Meinong, by Friend] |
7756 | Meinong said all objects of thought (even self-contradictions) have some sort of being [Meinong, by Lycan] |
15781 | The objects of knowledge are far more numerous than objects which exist [Meinong] |
1460 | Religious experience deserves the same respect as our other key experiences, and is best called 'holy' [Taylor,AE, by PG] |