15 ideas
18767 | Free logics has terms that do not designate real things, and even empty domains [Anderson,CA] |
18812 | Split out the logical vocabulary, make an assignment to the rest. It's logical if premises and conclusion match [Tarski, by Rumfitt] |
13344 | X follows from sentences K iff every model of K also models X [Tarski] |
18763 | Basic variables in second-order logic are taken to range over subsets of the individuals [Anderson,CA] |
18771 | Stop calling ∃ the 'existential' quantifier, read it as 'there is...', and range over all entities [Anderson,CA] |
13343 | A 'model' is a sequence of objects which satisfies a complete set of sentential functions [Tarski] |
18769 | Do mathematicians use 'existence' differently when they say some entity exists? [Anderson,CA] |
18770 | We can distinguish 'ontological' from 'existential' commitment, for different kinds of being [Anderson,CA] |
18768 | We cannot pick out a thing and deny its existence, but we can say a concept doesn't correspond [Anderson,CA] |
18766 | 's is non-existent' cannot be said if 's' does not designate [Anderson,CA] |
18765 | Individuation was a problem for medievals, then Leibniz, then Frege, then Wittgenstein (somewhat) [Anderson,CA] |
18764 | The notion of 'property' is unclear for a logical version of the Identity of Indiscernibles [Anderson,CA] |
13345 | Sentences are 'analytical' if every sequence of objects models them [Tarski] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |