101 ideas
13567 | Ontology should give insight into or an explanation of the world revealed by science [Ellis] |
224 | When questions are doubtful we should concentrate not on objects but on ideas of the intellect [Plato] |
232 | Opposites are as unlike as possible [Plato] |
8937 | Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic [Hegel on Plato] |
9724 | Until the 1960s the only semantics was truth-tables [Enderton] |
13604 | Real possibility and necessity has the logic of S5, which links equivalence classes of worlds of the same kind [Ellis] |
9707 | 'F(x)' is the unique value which F assumes for a value of x [Enderton] |
9705 | 'fld R' indicates the 'field' of all objects in the relation [Enderton] |
9704 | 'ran R' indicates the 'range' of objects being related to [Enderton] |
9703 | 'dom R' indicates the 'domain' of objects having a relation [Enderton] |
9710 | We write F:A→B to indicate that A maps into B (the output of F on A is in B) [Enderton] |
9699 | The 'powerset' of a set is all the subsets of a given set [Enderton] |
9700 | Two sets are 'disjoint' iff their intersection is empty [Enderton] |
9712 | A relation is 'symmetric' on a set if every ordered pair has the relation in both directions [Enderton] |
9713 | A relation is 'transitive' if it can be carried over from two ordered pairs to a third [Enderton] |
9701 | A 'relation' is a set of ordered pairs [Enderton] |
9702 | A 'domain' of a relation is the set of members of ordered pairs in the relation [Enderton] |
9708 | A function 'maps A into B' if the relating things are set A, and the things related to are all in B [Enderton] |
9709 | A function 'maps A onto B' if the relating things are set A, and the things related to are set B [Enderton] |
9711 | A relation is 'reflexive' on a set if every member bears the relation to itself [Enderton] |
9706 | A 'function' is a relation in which each object is related to just one other object [Enderton] |
9714 | A relation satisfies 'trichotomy' if all pairs are either relations, or contain identical objects [Enderton] |
9717 | A set is 'dominated' by another if a one-to-one function maps the first set into a subset of the second [Enderton] |
9716 | We 'partition' a set into distinct subsets, according to each relation on its objects [Enderton] |
9715 | An 'equivalence relation' is a reflexive, symmetric and transitive binary relation [Enderton] |
9722 | Inference not from content, but from the fact that it was said, is 'conversational implicature' [Enderton] |
9718 | Validity is either semantic (what preserves truth), or proof-theoretic (following procedures) [Enderton] |
9721 | A logical truth or tautology is a logical consequence of the empty set [Enderton] |
9994 | A truth assignment to the components of a wff 'satisfy' it if the wff is then True [Enderton] |
13606 | Humean conceptions of reality drive the adoption of extensional logic [Ellis] |
9719 | A proof theory is 'sound' if its valid inferences entail semantic validity [Enderton] |
9720 | A proof theory is 'complete' if semantically valid inferences entail proof-theoretic validity [Enderton] |
9995 | Proof in finite subsets is sufficient for proof in an infinite set [Enderton] |
9996 | Expressions are 'decidable' if inclusion in them (or not) can be proved [Enderton] |
9997 | For a reasonable language, the set of valid wff's can always be enumerated [Enderton] |
13986 | Plato found antinomies in ideas, Kant in space and time, and Bradley in relations [Plato, by Ryle] |
14150 | Plato's 'Parmenides' is perhaps the best collection of antinomies ever made [Russell on Plato] |
16150 | One is, so numbers exist, so endless numbers exist, and each one must partake of being [Plato] |
229 | The one was and is and will be and was becoming and is becoming and will become [Plato] |
21821 | Plato's Parmenides has a three-part theory, of Primal One, a One-Many, and a One-and-Many [Plato, by Plotinus] |
221 | Absolute ideas, such as the Good and the Beautiful, cannot be known by us [Plato] |
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] |
223 | If you deny that each thing always stays the same, you destroy the possibility of discussion [Plato] |
227 | You must always mean the same thing when you utter the same name [Plato] |
228 | Greatness and smallness must exist, to be opposed to one another, and come into being in things [Plato] |
211 | If admirable things have Forms, maybe everything else does as well [Plato] |
219 | If absolute ideas existed in us, they would cease to be absolute [Plato] |
16151 | Plato moves from Forms to a theory of genera and principles in his later work [Plato, by Frede,M] |
210 | It would be absurd to think there were abstract Forms for vile things like hair, mud and dirt [Plato] |
220 | The concept of a master includes the concept of a slave [Plato] |
212 | The whole idea of each Form must be found in each thing which participates in it [Plato] |
216 | If things are made alike by participating in something, that thing will be the absolute idea [Plato] |
215 | If things partake of ideas, this implies either that everything thinks, or that everything actually is thought [Plato] |
213 | Each idea is in all its participants at once, just as daytime is a unity but in many separate places at once [Plato] |
218 | Participation is not by means of similarity, so we are looking for some other method of participation [Plato] |
214 | If absolute greatness and great things are seen as the same, another thing appears which makes them seem great [Plato] |
217 | Nothing can be like an absolute idea, because a third idea intervenes to make them alike (leading to a regress) [Plato] |
15851 | Parts must belong to a created thing with a distinct form [Plato] |
15846 | In Parmenides, if composition is identity, a whole is nothing more than its parts [Plato, by Harte,V] |
15849 | Plato says only a one has parts, and a many does not [Plato, by Harte,V] |
15850 | Anything which has parts must be one thing, and parts are of a one, not of a many [Plato] |
13259 | It seems that the One must be composed of parts, which contradicts its being one [Plato] |
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] |
15847 | Two things relate either as same or different, or part of a whole, or the whole of the part [Plato] |
13576 | Necessities are distinguished by their grounds, not their different modalities [Ellis] |
9723 | Sentences with 'if' are only conditionals if they can read as A-implies-B [Enderton] |
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] |
222 | Only a great person can understand the essence of things, and an even greater person can teach it [Plato] |
225 | The unlimited has no shape and is endless [Plato] |
231 | Everything partakes of the One in some way [Plato] |
2062 | The only movement possible for the One is in space or in alteration [Plato] |
233 | Some things do not partake of the One [Plato] |
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] |
234 | We couldn't discuss the non-existence of the One without knowledge of it [Plato] |