Combining Texts

All the ideas for 'The Concept of Logical Consequence', 'Abstract Objects' and 'Formal and Material Consequence'

expand these ideas     |    start again     |     specify just one area for these texts

19 ideas

5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
14187 If logic is topic-neutral that means it delves into all subjects, rather than having a pure subject matter [Read]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
18812 Split out the logical vocabulary, make an assignment to the rest. It's logical if premises and conclusion match [Tarski, by Rumfitt]
14188 Not all arguments are valid because of form; validity is just true premises and false conclusion being impossible [Read]
14182 If the logic of 'taller of' rests just on meaning, then logic may be the study of merely formal consequence [Read]
14183 Maybe arguments are only valid when suppressed premises are all stated - but why? [Read]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
13344 X follows from sentences K iff every model of K also models X [Tarski]
5. Theory of Logic / B. Logical Consequence / 5. Modus Ponens
14184 In modus ponens the 'if-then' premise contributes nothing if the conclusion follows anyway [Read]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
14186 Logical connectives contain no information, but just record combination relations between facts [Read]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
13343 A 'model' is a sequence of objects which satisfies a complete set of sentential functions [Tarski]
9. Objects / A. Existence of Objects / 2. Abstract Objects / d. Problems with abstracta
8915 How we refer to abstractions is much less clear than how we refer to other things [Rosen]
10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
14185 Conditionals are just a shorthand for some proof, leaving out the details [Read]
18. Thought / E. Abstraction / 2. Abstracta by Selection
8917 The Way of Abstraction used to say an abstraction is an idea that was formed by abstracting [Rosen]
18. Thought / E. Abstraction / 5. Abstracta by Negation
8912 Nowadays abstractions are defined as non-spatial, causally inert things [Rosen]
8913 Chess may be abstract, but it has existed in specific space and time [Rosen]
8914 Sets are said to be abstract and non-spatial, but a set of books can be on a shelf [Rosen]
18. Thought / E. Abstraction / 6. Abstracta by Conflation
8916 Conflating abstractions with either sets or universals is a big claim, needing a big defence [Rosen]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
8918 Functional terms can pick out abstractions by asserting an equivalence relation [Rosen]
8919 Abstraction by equivalence relationships might prove that a train is an abstract entity [Rosen]
19. Language / E. Analyticity / 1. Analytic Propositions
13345 Sentences are 'analytical' if every sequence of objects models them [Tarski]