55 ideas
| 8797 | The negation of all my beliefs about my current headache would be fully coherent [Sosa] |
| 8877 | We can't attain a coherent system by lopping off any beliefs that won't fit [Sosa] |
| 15413 | With four tense operators, all complex tenses reduce to fourteen basic cases [Burgess] |
| 15415 | The temporal Barcan formulas fix what exists, which seems absurd [Burgess] |
| 15430 | Is classical logic a part of intuitionist logic, or vice versa? [Burgess] |
| 15431 | It is still unsettled whether standard intuitionist logic is complete [Burgess] |
| 15429 | Relevance logic's → is perhaps expressible by 'if A, then B, for that reason' [Burgess] |
| 15404 | Technical people see logic as any formal system that can be studied, not a study of argument validity [Burgess] |
| 15405 | Classical logic neglects the non-mathematical, such as temporality or modality [Burgess] |
| 15427 | The Cut Rule expresses the classical idea that entailment is transitive [Burgess] |
| 15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
| 15403 | Philosophical logic is a branch of logic, and is now centred in computer science [Burgess] |
| 15407 | Formalising arguments favours lots of connectives; proving things favours having very few [Burgess] |
| 15424 | Asserting a disjunction from one disjunct seems odd, but can be sensible, and needed in maths [Burgess] |
| 15409 | All occurrences of variables in atomic formulas are free [Burgess] |
| 15414 | The denotation of a definite description is flexible, rather than rigid [Burgess] |
| 15406 | 'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess] |
| 15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [Burgess] |
| 15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
| 15408 | 'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics [Burgess] |
| 15418 | Validity (for truth) and demonstrability (for proof) have correlates in satisfiability and consistency [Burgess] |
| 15412 | Models leave out meaning, and just focus on truth values [Burgess] |
| 15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
| 15416 | We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess] |
| 15428 | The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess] |
| 10185 | Set theory is the standard background for modern mathematics [Burgess] |
| 10184 | Structuralists take the name 'R' of the reals to be a variable ranging over structures, not a structure [Burgess] |
| 10189 | There is no one relation for the real number 2, as relations differ in different models [Burgess] |
| 10186 | If set theory is used to define 'structure', we can't define set theory structurally [Burgess] |
| 10187 | Abstract algebra concerns relations between models, not common features of all the models [Burgess] |
| 10188 | How can mathematical relations be either internal, or external, or intrinsic? [Burgess] |
| 8884 | The phenomenal concept of an eleven-dot pattern does not include the concept of eleven [Sosa] |
| 12887 | A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim] |
| 8443 | Mereological essentialism says an entity must have exactly those parts [Sosa] |
| 15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
| 15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
| 15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
| 15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
| 15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
| 8878 | It is acceptable to say a supermarket door 'knows' someone is approaching [Sosa] |
| 8880 | In reducing arithmetic to self-evident logic, logicism is in sympathy with rationalism [Sosa] |
| 8881 | Most of our knowledge has insufficient sensory support [Sosa] |
| 8794 | There are very few really obvious truths, and not much can be proved from them [Sosa] |
| 8882 | Perception may involve thin indexical concepts, or thicker perceptual concepts [Sosa] |
| 8883 | Do beliefs only become foundationally justified if we fully attend to features of our experience? [Sosa] |
| 8885 | Some features of a thought are known directly, but others must be inferred [Sosa] |
| 8876 | Much propositional knowledge cannot be formulated, as in recognising a face [Sosa] |
| 8796 | A single belief can trail two regresses, one terminating and one not [Sosa] |
| 8799 | If mental states are not propositional, they are logically dumb, and cannot be foundations [Sosa] |
| 8795 | Mental states cannot be foundational if they are not immune to error [Sosa] |
| 8879 | Fully comprehensive beliefs may not be knowledge [Sosa] |
| 8798 | Vision causes and justifies beliefs; but to some extent the cause is the justification [Sosa] |
| 8442 | What law would explain causation in the case of causing a table to come into existence? [Sosa] |
| 8445 | The necessitated is not always a result or consequence of the necessitator [Sosa] |
| 8444 | Where is the necessary causation in the three people being tall making everybody tall? [Sosa] |