74 ideas
9408 | Science studies phenomena, but only metaphysics tells us what exists [Mumford] |
9429 | Many forms of reasoning, such as extrapolation and analogy, are useful but deductively invalid [Mumford] |
13252 | Some truths have true negations [Beall/Restall] |
13247 | A truthmaker is an object which entails a sentence [Beall/Restall] |
13249 | (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall] |
13243 | Excluded middle must be true for some situation, not for all situations [Beall/Restall] |
13245 | Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall] |
13246 | Relevant logic does not abandon classical logic [Beall/Restall] |
13242 | It's 'relevantly' valid if all those situations make it true [Beall/Restall] |
13254 | A doesn't imply A - that would be circular [Beall/Restall] |
13255 | Relevant logic may reject transitivity [Beall/Restall] |
9672 | Free logic is one of the few first-order non-classical logics [Priest,G] |
13250 | Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall] |
9697 | X1 x X2 x X3... x Xn indicates the 'cartesian product' of those sets [Priest,G] |
9685 | <a,b&62; is a set whose members occur in the order shown [Priest,G] |
9674 | {x; A(x)} is a set of objects satisfying the condition A(x) [Priest,G] |
9673 | {a1, a2, ...an} indicates that a set comprising just those objects [Priest,G] |
9675 | a ∈ X says a is an object in set X; a ∉ X says a is not in X [Priest,G] |
9677 | Φ indicates the empty set, which has no members [Priest,G] |
9676 | {a} is the 'singleton' set of a (not the object a itself) [Priest,G] |
9678 | X⊆Y means set X is a 'subset' of set Y [Priest,G] |
9679 | X⊂Y means set X is a 'proper subset' of set Y [Priest,G] |
9681 | X = Y means the set X equals the set Y [Priest,G] |
9683 | X ∩ Y indicates the 'intersection' of sets X and Y, the objects which are in both sets [Priest,G] |
9684 | Y - X is the 'relative complement' of X with respect to Y; the things in Y that are not in X [Priest,G] |
9682 | X∪Y indicates the 'union' of all the things in sets X and Y [Priest,G] |
9692 | The 'union' of two sets is a set containing all the things in either of the sets [Priest,G] |
9693 | The 'intersection' of two sets is a set of the things that are in both sets [Priest,G] |
9694 | The 'relative complement' is things in the second set not in the first [Priest,G] |
9698 | The 'induction clause' says complex formulas retain the properties of their basic formulas [Priest,G] |
9696 | A 'cartesian product' of sets is the set of all the n-tuples with one member in each of the sets [Priest,G] |
9686 | A 'set' is a collection of objects [Priest,G] |
9687 | A 'member' of a set is one of the objects in the set [Priest,G] |
9695 | An 'ordered pair' (or ordered n-tuple) is a set with its members in a particular order [Priest,G] |
9688 | A 'singleton' is a set with only one member [Priest,G] |
9689 | The 'empty set' or 'null set' has no members [Priest,G] |
9690 | A set is a 'subset' of another set if all of its members are in that set [Priest,G] |
9691 | A 'proper subset' is smaller than the containing set [Priest,G] |
9680 | The empty set Φ is a subset of every set (including itself) [Priest,G] |
13235 | Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall] |
13238 | Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall] |
13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |
13232 | Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall] |
13241 | The model theory of classical predicate logic is mathematics [Beall/Restall] |
13253 | There are several different consequence relations [Beall/Restall] |
13240 | A sentence follows from others if they always model it [Beall/Restall] |
13236 | Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall] |
13237 | Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall] |
9427 | For Humeans the world is a world primarily of events [Mumford] |
9446 | Properties are just natural clusters of powers [Mumford] |
9435 | A 'porridge' nominalist thinks we just divide reality in any way that suits us [Mumford] |
9447 | If properties are clusters of powers, this can explain why properties resemble in degrees [Mumford] |
12248 | How can we show that a universally possessed property is an essential property? [Mumford] |
13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
13239 | Judgement is always predicating a property of a subject [Beall/Restall] |
13248 | We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall] |
13233 | Propositions commit to content, and not to any way of spelling it out [Beall/Restall] |
9430 | Singular causes, and identities, might be necessary without falling under a law [Mumford] |
9445 | We can give up the counterfactual account if we take causal language at face value [Mumford] |
9443 | It is only properties which are the source of necessity in the world [Mumford] |
9444 | There are four candidates for the logical form of law statements [Mumford] |
9416 | Regularities are more likely with few instances, and guaranteed with no instances! [Mumford] |
9415 | Would it count as a regularity if the only five As were also B? [Mumford] |
9431 | Pure regularities are rare, usually only found in idealized conditions [Mumford] |
9441 | Regularity laws don't explain, because they have no governing role [Mumford] |
9421 | The best systems theory says regularities derive from laws, rather than constituting them [Mumford] |
9422 | If the best system describes a nomological system, the laws are in nature, not in the description [Mumford] |
9432 | Laws of nature are necessary relations between universal properties, rather than about particulars [Mumford] |
9433 | If laws can be uninstantiated, this favours the view of them as connecting universals [Mumford] |
9434 | Laws of nature are just the possession of essential properties by natural kinds [Mumford] |
9437 | To distinguish accidental from essential properties, we must include possible members of kinds [Mumford] |
9411 | There are no laws of nature in Aristotle; they became standard with Descartes and Newton [Mumford] |
9439 | The Central Dilemma is how to explain an internal or external view of laws which govern [Mumford] |
9412 | You only need laws if you (erroneously) think the world is otherwise inert [Mumford] |