55 ideas
13567 | Ontology should give insight into or an explanation of the world revealed by science [Ellis] |
13520 | A 'tautology' must include connectives [Wolf,RS] |
13524 | Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS] |
13521 | Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS] |
13522 | Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS] |
13523 | Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS] |
13604 | Real possibility and necessity has the logic of S5, which links equivalence classes of worlds of the same kind [Ellis] |
13529 | Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS] |
13526 | Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS] |
13534 | In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS] |
13535 | First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS] |
13606 | Humean conceptions of reality drive the adoption of extensional logic [Ellis] |
13519 | Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS] |
13531 | Model theory reveals the structures of mathematics [Wolf,RS] |
13532 | Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS] |
13533 | First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS] |
13537 | An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS] |
13539 | The LST Theorem is a serious limitation of first-order logic [Wolf,RS] |
13538 | If a theory is complete, only a more powerful language can strengthen it [Wolf,RS] |
13525 | Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS] |
13530 | An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS] |
13518 | Modern mathematics has unified all of its objects within set theory [Wolf,RS] |
13584 | The extension of a property is a contingent fact, so cannot be the essence of the property [Ellis] |
13587 | There is no property of 'fragility', as things are each fragile in a distinctive way [Ellis] |
13577 | Typical 'categorical' properties are spatio-temporal, such as shape [Ellis] |
9436 | The property of 'being an electron' is not of anything, and only electrons could have it [Ellis] |
13582 | 'Being a methane molecule' is not a property - it is just a predicate [Ellis] |
13580 | Causal powers must necessarily act the way they do [Ellis] |
13598 | Causal powers are often directional (e.g. centripetal, centrifugal, circulatory) [Ellis] |
13568 | Basic powers may not be explained by structure, if at the bottom level there is no structure [Ellis] |
13586 | Maybe dispositions can be explained by intrinsic properties or structures [Ellis] |
13585 | The most fundamental properties of nature (mass, charge, spin ...) all seem to be dispositions [Ellis] |
13596 | A causal power is a disposition to produce forces [Ellis] |
13599 | Powers are dispositions of the essences of kinds that involve them in causation [Ellis] |
13572 | There are 'substantive' (objects of some kind), 'dynamic' (events of some kind) and 'property' universals [Ellis] |
13573 | Universals are all types of natural kind [Ellis] |
13571 | Scientific essentialism doesn't really need Kripkean individual essences [Ellis] |
13578 | The old idea that identity depends on essence and behaviour is rejected by the empiricists [Ellis] |
13576 | Necessities are distinguished by their grounds, not their different modalities [Ellis] |
13570 | Individual essences necessitate that individual; natural kind essences necessitate kind membership [Ellis] |
13607 | If events are unconnected, then induction cannot be solved [Ellis] |
13597 | Good explanations unify [Ellis] |
13601 | Explanations of particular events are not essentialist, as they don't reveal essential structures [Ellis] |
13569 | To give essentialist explanations there have to be natural kinds [Ellis] |
13600 | The point of models in theories is not to idealise, but to focus on what is essential [Ellis] |
7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
13583 | There might be uninstantiated natural kinds, such as transuranic elements which have never occurred [Ellis] |
13574 | Natural kinds are distinguished by resting on essences [Ellis] |
13575 | If there are borderline cases between natural kinds, that makes them superficial [Ellis] |
13595 | Laws don't exist in the world; they are true of the world [Ellis] |
13566 | A proton must have its causal role, because without it it wouldn't be a proton [Ellis] |
13579 | What is most distinctive of scientific essentialism is regarding processes as natural kinds [Ellis] |
13581 | Scientific essentialism is more concerned with explanation than with identity (Locke, not Kripke) [Ellis] |
13594 | The ontological fundamentals are dispositions, and also categorical (spatio-temporal and structural) properties [Ellis] |
13603 | A primary aim of science is to show the limits of the possible [Ellis] |