103 ideas
5988 | Anaximander produced the first philosophy book (and maybe the first book) [Anaximander, by Bodnár] |
9414 | Metaphysics is the mapping of possibilities [Lowe, by Mumford] |
16414 | Science needs metaphysics to weed out its presuppositions [Lowe, by Hofweber] |
8282 | Only metaphysics can decide whether identity survives through change [Lowe] |
16127 | Metaphysics tells us what there could be, rather than what there is [Lowe] |
1496 | The earth is stationary, because it is in the centre, and has no more reason to move one way than another [Anaximander, by Aristotle] |
8262 | How can a theory of meaning show the ontological commitments of two paraphrases of one idea? [Lowe] |
8315 | Maybe facts are just true propositions [Lowe] |
8319 | One-to-one correspondence would need countable, individuable items [Lowe] |
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] |
8309 | A set is a 'number of things', not a 'collection', because nothing actually collects the members [Lowe] |
8322 | I don't believe in the empty set, because (lacking members) it lacks identity-conditions [Lowe] |
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] |
15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
15427 | The Cut Rule expresses the classical idea that entailment is transitive [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] |
8312 | It is better if the existential quantifier refers to 'something', rather than a 'thing' which needs individuation [Lowe] |
15406 | 'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess] |
15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [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] |
15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
15412 | Models leave out meaning, and just focus on truth values [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] |
8297 | Numbers are universals, being sets whose instances are sets of appropriate cardinality [Lowe] |
8266 | Simple counting is more basic than spotting that one-to-one correlation makes sets equinumerous [Lowe] |
8302 | Fs and Gs are identical in number if they one-to-one correlate with one another [Lowe] |
8298 | Sets are instances of numbers (rather than 'collections'); numbers explain sets, not vice versa [Lowe] |
8311 | If 2 is a particular, then adding particulars to themselves does nothing, and 2+2=2 [Lowe] |
8310 | Does the existence of numbers matter, in the way space, time and persons do? [Lowe] |
14874 | Anaximander saw the contradiction in the world - that its own qualities destroy it [Anaximander, by Nietzsche] |
8321 | All possible worlds contain abstracta (e.g. numbers), which means they contain concrete objects [Lowe] |
8300 | Perhaps possession of causal power is the hallmark of existence (and a reason to deny the void) [Lowe] |
8281 | Heraclitus says change is new creation, and Spinoza that it is just phases of the one substance [Lowe] |
8270 | Events are changes or non-changes in properties and relations of persisting objects [Lowe] |
8308 | Events are ontologically indispensable for singular causal explanations [Lowe] |
8314 | Are facts wholly abstract, or can they contain some concrete constituents? [Lowe] |
8316 | Facts cannot be wholly abstract if they enter into causal relations [Lowe] |
8318 | The problem with the structured complex view of facts is what binds the constituents [Lowe] |
8323 | It is whimsical to try to count facts - how many facts did I learn before breakfast? [Lowe] |
8313 | Facts are needed for truth-making and causation, but they seem to lack identity criteria [Lowe] |
8258 | Two of the main rivals for the foundations of ontology are substances, and facts or states-of-affairs [Lowe] |
8301 | Some abstractions exist despite lacking causal powers, because explanation needs them [Lowe] |
8283 | Ontological categories are not natural kinds: the latter can only be distinguished using the former [Lowe] |
8284 | The top division of categories is either abstract/concrete, or universal/particular, or necessary/contingent [Lowe] |
13122 | Lowe divides things into universals and particulars, then kinds and properties, and abstract/concrete [Lowe, by Westerhoff] |
8273 | Is 'the Thames is broad in London' relational, or adverbial, or segmental? [Lowe] |
8285 | I prefer 'modes' to 'tropes', because it emphasises their dependence [Lowe] |
8286 | Tropes cannot have clear identity-conditions, so they are not objects [Lowe] |
8294 | How can tropes depend on objects for their identity, if objects are just bundles of tropes? [Lowe] |
8295 | Why cannot a trope float off and join another bundle? [Lowe] |
8296 | Does a ball snug in plaster have one trope, or two which coincide? [Lowe] |
8288 | Sortal terms for universals involve a substance, whereas adjectival terms do not [Lowe] |
8293 | Real universals are needed to explain laws of nature [Lowe] |
8307 | Particulars are instantiations, and universals are instantiables [Lowe] |
8267 | Perhaps concrete objects are entities which are in space-time and subject to causality [Lowe] |
8265 | Our commitment to the existence of objects should depend on their explanatory value [Lowe] |
8275 | Objects are entities with full identity-conditions, but there are entities other than objects [Lowe] |
16130 | To be an object at all requires identity-conditions [Lowe] |
8263 | An object is an entity which has identity-conditions [Lowe] |
8268 | Some things (such as electrons) can be countable, while lacking proper identity [Lowe] |
8303 | Criteria of identity cannot individuate objects, because they are shared among different types [Lowe] |
8292 | Diversity of two tigers is their difference in space-time; difference of matter is a consequence [Lowe] |
8291 | Individuation principles identify what kind it is; identity criteria distinguish items of the same kind [Lowe] |
16128 | A 'substance' is an object which doesn't depend for existence on other objects [Lowe] |
8279 | The identity of composite objects isn't fixed by original composition, because how do you identify the origin? [Lowe] |
8271 | An object 'endures' if it is always wholly present, and 'perdures' if different parts exist at different times [Lowe] |
8272 | How can you identify temporal parts of tomatoes without referring to tomatoes? [Lowe] |
8305 | A clear idea of the kind of an object must precede a criterion of identity for it [Lowe] |
8290 | One view is that two objects of the same type are only distinguished by differing in matter [Lowe] |
15079 | 'Conceptual' necessity is narrow logical necessity, true because of concepts and logical laws [Lowe] |
15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
16063 | Metaphysical necessity is logical necessity 'broadly construed' [Lowe, by Lynch/Glasgow] |
15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
8260 | Logical necessity can be 'strict' (laws), or 'narrow' (laws and definitions), or 'broad' (all logical worlds) [Lowe] |
15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
16131 | The metaphysically possible is what acceptable principles and categories will permit [Lowe] |
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] |
8320 | Does every abstract possible world exist in every possible world? [Lowe] |
8280 | While space may just be appearance, time and change can't be, because the appearances change [Lowe] |
8276 | Properties or qualities are essentially adjectival, not objectual [Lowe] |
8289 | The idea that Cartesian souls are made of some ghostly 'immaterial' stuff is quite unwarranted [Lowe] |
8299 | Abstractions are non-spatial, or dependent, or derived from concepts [Lowe] |
8306 | You can think of a direction without a line, but a direction existing with no lines is inconceivable [Lowe] |
13222 | The Boundless cannot exist on its own, and must have something contrary to it [Aristotle on Anaximander] |
1495 | Anaximander introduced the idea that the first principle and element of things was the Boundless [Anaximander, by Simplicius] |
404 | Things begin and end in the Unlimited, and are balanced over time according to justice [Anaximander] |
405 | The essential nature, whatever it is, of the non-limited is everlasting and ageless [Anaximander] |
8317 | To cite facts as the elements in causation is to confuse states of affairs with states of objects [Lowe] |
8269 | Points are limits of parts of space, so parts of space cannot be aggregates of them [Lowe] |
1746 | The parts of all things are susceptible to change, but the whole is unchangeable [Anaximander, by Diog. Laertius] |