71 ideas
13395 | If an analysis shows the features of a concept, it doesn't seem to 'reduce' the concept [Jubien] |
17749 | Post proved the consistency of propositional logic in 1921 [Walicki] |
17765 | Propositional language can only relate statements as the same or as different [Walicki] |
17764 | Boolean connectives are interpreted as functions on the set {1,0} [Walicki] |
17752 | The empty set is useful for defining sets by properties, when the members are not yet known [Walicki] |
17753 | The empty set avoids having to take special precautions in case members vanish [Walicki] |
17759 | Ordinals play the central role in set theory, providing the model of well-ordering [Walicki] |
17741 | To determine the patterns in logic, one must identify its 'building blocks' [Walicki] |
13378 | It is a mistake to think that the logic developed for mathematics can clarify language and philosophy [Jubien] |
13402 | We only grasp a name if we know whether to apply it when the bearer changes [Jubien] |
13405 | The baptiser picks the bearer of a name, but social use decides the category [Jubien] |
13399 | Examples show that ordinary proper names are not rigid designators [Jubien] |
13398 | We could make a contingent description into a rigid and necessary one by adding 'actual' to it [Jubien] |
13392 | Philosophers reduce complex English kind-quantifiers to the simplistic first-order quantifier [Jubien] |
17747 | A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki] |
17748 | The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki] |
17761 | A compact axiomatisation makes it possible to understand a field as a whole [Walicki] |
17763 | Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki] |
17758 | Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki] |
17755 | Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki] |
17756 | The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki] |
17760 | Two infinite ordinals can represent a single infinite cardinal [Walicki] |
17757 | Members of ordinals are ordinals, and also subsets of ordinals [Walicki] |
17762 | In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki] |
17754 | Inductive proof depends on the choice of the ordering [Walicki] |
16588 | I prefer a lack of form to mean non-existence, than to think of some quasi-existence [Augustine] |
13404 | To exist necessarily is to have an essence whose own essence must be instantiated [Jubien] |
13386 | If objects are just conventional, there is no ontological distinction between stuff and things [Jubien] |
22979 | Three main questions seem to be whether a thing is, what it is, and what sort it is [Augustine] |
13403 | The category of Venus is not 'object', or even 'planet', but a particular class of good-sized object [Jubien] |
13375 | The idea that every entity must have identity conditions is an unfortunate misunderstanding [Jubien] |
13393 | Any entity has the unique property of being that specific entity [Jubien] |
13388 | It is incoherent to think that a given entity depends on its kind for its existence [Jubien] |
13384 | Objects need conventions for their matter, their temporal possibility, and their spatial possibility [Jubien] |
13385 | Basically, the world doesn't have ready-made 'objects'; we carve objects any way we like [Jubien] |
13383 | If the statue is loved and the clay hated, that is about the object first qua statue, then qua clay [Jubien] |
13400 | If one entity is an object, a statue, and some clay, these come apart in at least three ways [Jubien] |
13401 | The idea of coincident objects is a last resort, as it is opposed to commonsense naturalism [Jubien] |
13380 | Parts seem to matter when it is just an object, but not matter when it is a kind of object [Jubien] |
13376 | We should not regard essentialism as just nontrivial de re necessity [Jubien] |
13381 | Thinking of them as 'ships' the repaired ship is the original, but as 'objects' the reassembly is the original [Jubien] |
13382 | Rearranging the planks as a ship is confusing; we'd say it was the same 'object' with a different arrangement [Jubien] |
13379 | If two objects are indiscernible across spacetime, how could we decide whether or not they are the same? [Jubien] |
17742 | Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki] |
13394 | Entailment does not result from mutual necessity; mutual necessity ensures entailment [Jubien] |
13391 | Modality concerns relations among platonic properties [Jubien] |
13374 | To analyse modality, we must give accounts of objects, properties and relations [Jubien] |
13389 | The love of possible worlds is part of the dream that technical logic solves philosophical problems [Jubien] |
13390 | Possible worlds don't explain necessity, because they are a bunch of parallel contingencies [Jubien] |
22981 | Mind and memory are the same, as shown in 'bear it in mind' or 'it slipped from mind' [Augustine] |
22980 | Memory contains innumerable principles of maths, as well as past sense experiences [Augustine] |
22983 | We would avoid remembering sorrow or fear if that triggered the emotions afresh [Augustine] |
22977 | I can distinguish different smells even when I am not experiencing them [Augustine] |
22982 | Why does joy in my mind make me happy, but joy in my memory doesn't? [Augustine] |
22978 | Memory is so vast that I cannot recognise it as part of my mind [Augustine] |
22984 | Without memory I could not even speak of myself [Augustine] |
5982 | If the future does not exist, how can prophets see it? [Augustine] |
13396 | Analysing mental concepts points to 'inclusionism' - that mental phenomena are part of the physical [Jubien] |
22976 | Memories are preserved separately, according to category [Augustine] |
13377 | First-order logic tilts in favour of the direct reference theory, in its use of constants for objects [Jubien] |
22985 | Everyone wants happiness [Augustine] |
5984 | Maybe time is an extension of the mind [Augustine] |
22888 | To be aware of time it can only exist in the mind, as memory or anticipation [Augustine, by Bardon] |
5980 | How can ten days ahead be a short time, if it doesn't exist? [Augustine] |
5979 | If the past is no longer, and the future is not yet, how can they exist? [Augustine] |
5981 | The whole of the current year is not present, so how can it exist? [Augustine] |
5978 | I know what time is, until someone asks me to explain it [Augustine] |
5983 | I disagree with the idea that time is nothing but cosmic movement [Augustine] |
5977 | Heaven and earth must be created, because they are subject to change [Augustine] |
22887 | If God existed before creation, why would a perfect being desire to change things? [Augustine, by Bardon] |
5976 | If God is outside time in eternity, can He hear prayers? [Augustine] |