68 ideas
| 13786 | Wisdom is called 'beautiful', because it performs fine works [Plato] |
| 13780 | Good people are no different from wise ones [Plato] |
| 17275 | Realist metaphysics concerns what is real; naive metaphysics concerns natures of things [Fine,K] |
| 13778 | A dialectician is someone who knows how to ask and to answer questions [Plato] |
| 17282 | Truths need not always have their source in what exists [Fine,K] |
| 17283 | If the truth-making relation is modal, then modal truths will be grounded in anything [Fine,K] |
| 13776 | Truths say of what is that it is, falsehoods say of what is that it is not [Plato] |
| 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] |
| 17286 | Logical consequence is verification by a possible world within a truth-set [Fine,K] |
| 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] |
| 13777 | A name is a sort of tool [Plato] |
| 13790 | A name-giver might misname something, then force other names to conform to it [Plato] |
| 13791 | Things must be known before they are named, so it can't be the names that give us knowledge [Plato] |
| 13789 | Anyone who knows a thing's name also knows the thing [Plato] |
| 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] |
| 2063 | How can beauty have identity if it changes? [Plato] |
| 17272 | 2+2=4 is necessary if it is snowing, but not true in virtue of the fact that it is snowing [Fine,K] |
| 17276 | If you say one thing causes another, that leaves open that the 'other' has its own distinct reality [Fine,K] |
| 17284 | An immediate ground is the next lower level, which gives the concept of a hierarchy [Fine,K] |
| 17285 | 'Strict' ground moves down the explanations, but 'weak' ground can move sideways [Fine,K] |
| 17288 | We learn grounding from what is grounded, not what does the grounding [Fine,K] |
| 17281 | If grounding is a relation it must be between entities of the same type, preferably between facts [Fine,K] |
| 17280 | Ground is best understood as a sentence operator, rather than a relation between predicates [Fine,K] |
| 17290 | Only metaphysical grounding must be explained by essence [Fine,K] |
| 17274 | Philosophical explanation is largely by ground (just as cause is used in science) [Fine,K] |
| 17278 | We can only explain how a reduction is possible if we accept the concept of ground [Fine,K] |
| 17287 | Facts, such as redness and roundness of a ball, can be 'fused' into one fact [Fine,K] |
| 13775 | We only succeed in cutting if we use appropriate tools, not if we approach it randomly [Plato] |
| 13787 | Doesn't each thing have an essence, just as it has other qualities? [Plato] |
| 13774 | Things don't have every attribute, and essence isn't private, so each thing has an essence [Plato] |
| 13772 | Is the being or essence of each thing private to each person? [Plato] |
| 17279 | Even a three-dimensionalist might identify temporal parts, in their thinking [Fine,K] |
| 13788 | If we made a perfect duplicate of Cratylus, there would be two Cratyluses [Plato] |
| 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] |
| 17273 | Each basic modality has its 'own' explanatory relation [Fine,K] |
| 17289 | Every necessary truth is grounded in the nature of something [Fine,K] |
| 13792 | There can't be any knowledge if things are constantly changing [Plato] |
| 17291 | We explain by identity (what it is), or by truth (how things are) [Fine,K] |
| 17271 | Is there metaphysical explanation (as well as causal), involving a constitutive form of determination? [Fine,K] |
| 13781 | Soul causes the body to live, and gives it power to breathe and to be revitalized [Plato] |
| 17277 | If mind supervenes on the physical, it may also explain the physical (and not vice versa) [Fine,K] |
| 13785 | 'Arete' signifies lack of complexity and a free-flowing soul [Plato] |
| 13779 | The natural offspring of a lion is called a 'lion' (but what about the offspring of a king?) [Plato] |
| 13783 | Even the gods love play [Plato] |