193 ideas
16395 | Kripke separated semantics from metaphysics, rather than linking them, making the latter independent [Kripke, by Stalnaker] |
17034 | Analyses of concepts using entirely different terms are very inclined to fail [Kripke] |
4955 | Some definitions aim to fix a reference rather than give a meaning [Kripke] |
15327 | Kripke's semantic theory has actually inspired promising axiomatic theories [Kripke, by Horsten] |
15343 | Kripke offers a semantic theory of truth (involving models) [Kripke, by Horsten] |
14966 | The Tarskian move to a metalanguage may not be essential for truth theories [Kripke, by Gupta] |
14967 | Certain three-valued languages can contain their own truth predicates [Kripke, by Gupta] |
16328 | Kripke classified fixed points, and illuminated their use for clarifications [Kripke, by Halbach] |
9724 | Until the 1960s the only semantics was truth-tables [Enderton] |
10163 | Propositional modal logic has been proved to be complete [Kripke, by Feferman/Feferman] |
10559 | Kripke's modal semantics presupposes certain facts about possible worlds [Kripke, by Zalta] |
16985 | Possible worlds allowed the application of set-theoretic models to modal logic [Kripke] |
10760 | With possible worlds, S4 and S5 are sound and complete, but S1-S3 are not even sound [Kripke, by Rossberg] |
16189 | The variable domain approach to quantified modal logic invalidates the Barcan Formula [Kripke, by Simchen] |
15132 | The Barcan formulas fail in models with varying domains [Kripke, by Williamson] |
9703 | 'dom R' indicates the 'domain' of objects having a relation [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] |
9710 | We write F:A→B to indicate that A maps into B (the output of F on A is in B) [Enderton] |
9707 | 'F(x)' is the unique value which F assumes for a value of x [Enderton] |
13201 | ∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [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] |
13204 | The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton] |
13206 | A 'linear or total ordering' must be transitive and satisfy trichotomy [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] |
9702 | A 'domain' of a relation is the set of members of ordered pairs in the relation [Enderton] |
9701 | A 'relation' is a set of ordered pairs [Enderton] |
9706 | A 'function' is a relation in which each object is related to just one other object [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] |
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] |
13200 | Note that {Φ} =/= Φ, because Φ ∈ {Φ} but Φ ∉ Φ [Enderton] |
13199 | The empty set may look pointless, but many sets can be constructed from it [Enderton] |
13203 | The singleton is defined using the pairing axiom (as {x,x}) [Enderton] |
9715 | An 'equivalence relation' is a reflexive, symmetric and transitive binary relation [Enderton] |
9716 | We 'partition' a set into distinct subsets, according to each relation on its objects [Enderton] |
13202 | Fraenkel added Replacement, to give a theory of ordinal numbers [Enderton] |
13205 | We can only define functions if Choice tells us which items are involved [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] |
10437 | Names are rigid, making them unlike definite descriptions [Kripke, by Sainsbury] |
4949 | Names are rigid designators, which designate the same object in all possible worlds [Kripke] |
4951 | A bundle of qualities is a collection of abstractions, so it can't be a particular [Kripke] |
17031 | A name can still refer even if it satisfies none of its well-known descriptions [Kripke] |
9175 | We may fix the reference of 'Cicero' by a description, but thereafter the name is rigid [Kripke] |
8957 | Some references, such as 'Neptune', have to be fixed by description rather than baptism [Kripke, by Szabó] |
9171 | The function of names is simply to refer [Kripke] |
10428 | Proper names must have referents, because they are not descriptive [Kripke, by Sainsbury] |
4959 | A name's reference is not fixed by any marks or properties of the referent [Kripke] |
16982 | A man has two names if the historical chains are different - even if they are the same! [Kripke] |
10792 | The substitutional quantifier is not in competition with the standard interpretation [Kripke, by Marcus (Barcan)] |
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] |
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] |
14896 | Kripke's metaphysics (essences, kinds, rigidity) blocks the slide into sociology [Kripke, by Ladyman/Ross] |
17000 | We might fix identities for small particulars, but it is utopian to hope for such things [Kripke] |
17647 | Kripke individuates objects by essential modal properties (and presupposes essentialism) [Kripke, by Putnam] |
16995 | Given that a table is made of molecules, could it not be molecular and still be this table? [Kripke] |
17047 | If we imagine this table made of ice or different wood, we are imagining a different table [Kripke] |
11868 | A different piece of wood could have been used for that table; constitution isn't identity [Wiggins on Kripke] |
5450 | For Kripke, essence is origin; for Putnam, essence is properties; for Wiggins, essence is membership of a kind [Kripke, by Mautner] |
17055 | Atomic number 79 is part of the nature of the gold we know [Kripke] |
16997 | An essential property is true of an object in any case where it would have existed [Kripke] |
17045 | De re modality is an object having essential properties [Kripke] |
17030 | Important properties of an object need not be essential to it [Kripke] |
16955 | Kripke says internal structure fixes species; I say it is genetic affinity and a common descent [Kripke, by Dummett] |
16996 | Given that Nixon is indeed a human being, that he might not have been does not concern knowledge [Kripke] |
13971 | Kripke claims that some properties, only knowable posteriori, are known a priori to be essential [Kripke, by Soames] |
12100 | An essence is the necessary properties, derived from an intuitive identity, in origin, type and material [Kripke, by Witt] |
16991 | No one seems to know the identity conditions for a material object (or for people) over time [Kripke] |
11867 | If we lose track of origin, how do we show we are maintaining a reference? [Kripke, by Wiggins] |
12018 | Kripke argues, of the Queen, that parents of an organism are essentially so [Kripke, by Forbes,G] |
17046 | Could the actual Queen have been born of different parents? [Kripke] |
8274 | Socrates can't have a necessary origin, because he might have had no 'origin' [Lowe on Kripke] |
16981 | With the necessity of self-identity plus Leibniz's Law, identity has to be an 'internal' relation [Kripke] |
17044 | A relation can clearly be reflexive, and identity is the smallest reflexive relation [Kripke] |
17036 | Identity statements can be contingent if they rely on descriptions [Kripke] |
17038 | If Hesperus and Phosophorus are the same, they can't possibly be different [Kripke] |
4942 | The indiscernibility of identicals is as self-evident as the law of contradiction [Kripke] |
16999 | A vague identity may seem intransitive, and we might want to talk of 'counterparts' [Kripke] |
11880 | Kripke says his necessary a posteriori examples are known a priori to be necessary [Kripke, by Mackie,P] |
17058 | What many people consider merely physically necessary I consider completely necessary [Kripke] |
4797 | Instead of being regularities, maybe natural laws are the weak a posteriori necessities of Kripke [Kripke, by Psillos] |
4970 | What is often held to be mere physical necessity is actually metaphysical necessity [Kripke] |
17037 | Physical necessity may be necessity in the highest degree [Kripke] |
17059 | Unicorns are vague, so no actual or possible creature could count as a unicorn [Kripke] |
9723 | Sentences with 'if' are only conditionals if they can read as A-implies-B [Enderton] |
16984 | I don't think possible worlds reductively reveal the natures of modal operators etc. [Kripke] |
4728 | Kripke separates necessary and a priori, proposing necessary a posteriori and contingent a priori examples [Kripke, by O'Grady] |
16990 | A priori = Necessary because we imagine all worlds, and we know without looking at actuality? [Kripke] |
9386 | The meter is defined necessarily, but the stick being one meter long is contingent a priori [Kripke] |
9385 | The very act of designating of an object with properties gives knowledge of a contingent truth [Kripke] |
4960 | "'Hesperus' is 'Phosphorus'" is necessarily true, if it is true, but not known a priori [Kripke] |
4966 | Theoretical identities are between rigid designators, and so are necessary a posteriori [Kripke] |
9174 | It is necessary that this table is not made of ice, but we don't know it a priori [Kripke] |
2408 | Kripke has demonstrated that some necessary truths are only knowable a posteriori [Kripke, by Chalmers] |
13967 | Kripke's essentialist necessary a posteriori opened the gap between conceivable and really possible [Soames on Kripke] |
13970 | Kripke gets to the necessary a posteriori by only allowing conceivability when combined with actuality [Kripke, by Soames] |
4943 | Instead of talking about possible worlds, we can always say "It is possible that.." [Kripke] |
4950 | Possible worlds are useful in set theory, but can be very misleading elsewhere [Kripke] |
16992 | Possible worlds aren't puzzling places to learn about, but places we ourselves describe [Kripke] |
16983 | Probability with dice uses possible worlds, abstractions which fictionally simplify things [Kripke] |
16993 | If we discuss what might have happened to Nixon, we stipulate that it is about Nixon [Kripke] |
16998 | Transworld identification is unproblematic, because we stipulate that we rigidly refer to something [Kripke] |
17001 | A table in some possible world should not even be identified by its essential properties [Kripke] |
4952 | Identification across possible worlds does not need properties, even essential ones [Kripke] |
7761 | Test for rigidity by inserting into the sentence 'N might not have been N' [Kripke, by Lycan] |
7693 | Kripke avoids difficulties of transworld identity by saying it is a decision, not a discovery [Kripke, by Jacquette] |
5821 | Saying that natural kinds are 'rigid designators' is the same as saying they are 'indexical' [Kripke, by Putnam] |
14068 | If Kripke names must still denote a thing in a non-actual situation, the statue isn't its clay [Gibbard on Kripke] |
10436 | A rigid expression may refer at a world to an object not existing in that world [Kripke, by Sainsbury] |
4953 | We do not begin with possible worlds and place objects in them; we begin with objects in the real world [Kripke] |
4961 | It is a necessary truth that Elizabeth II was the child of two particular parents [Kripke] |
9172 | A 'rigid designator' designates the same object in all possible worlds [Kripke] |
9173 | We cannot say that Nixon might have been a different man from the one he actually was [Kripke] |
17003 | Kaplan's 'Dthat' is a useful operator for transforming a description into a rigid designation [Kripke] |
9176 | Modal statements about this table never refer to counterparts; that confuses epistemology and metaphysics [Kripke] |
9221 | The best known objection to counterparts is Kripke's, that Humphrey doesn't care if his counterpart wins [Kripke, by Sider] |
16986 | That there might have been unicorns is false; we don't know the circumstances for unicorns [Kripke] |
8259 | Kripke has breathed new life into the a priori/a posteriori distinction [Kripke, by Lowe] |
16989 | Rather than 'a priori truth', it is best to stick to whether some person knows it on a priori evidence [Kripke] |
4947 | A priori truths can be known independently of experience - but they don't have to be [Kripke] |
17052 | The a priori analytic truths involving fixing of reference are contingent [Kripke] |
13975 | Kripke was more successful in illuminating necessity than a priority (and their relations to analyticity) [Kripke, by Soames] |
17048 | Analytic judgements are a priori, even when their content is empirical [Kripke] |
4948 | Intuition is the strongest possible evidence one can have about anything [Kripke] |
4958 | Identities like 'heat is molecule motion' are necessary (in the highest degree), not contingent [Kripke] |
4969 | I regard the mind-body problem as wide open, and extremely confusing [Kripke] |
4967 | It seems logically possible to have the pain brain state without the actual pain [Kripke] |
9177 | Identity theorists must deny that pains can be imagined without brain states [Kripke] |
7430 | Kripke assumes that mind-brain identity designates rigidly, which it doesn't [Armstrong on Kripke] |
7867 | If consciousness could separate from brain, then it cannot be identical with brain [Kripke, by Papineau] |
3228 | Kripke says pain is necessarily pain, but a brain state isn't necessarily painful [Kripke, by Rey] |
5832 | Identity must be necessary, but pain isn't necessarily a brain state, so they aren't identical [Kripke, by Schwartz,SP] |
4968 | Identity theorists seem committed to no-brain-event-no-pain, and vice versa, which seems wrong [Kripke] |
9178 | Pain, unlike heat, is picked out by an essential property [Kripke] |
19271 | No rule can be fully explained [Kripke] |
19269 | 'Quus' means the same as 'plus' if the ingredients are less than 57; otherwise it just produces 5 [Kripke] |
16383 | Puzzled Pierre has two mental files about the same object [Recanati on Kripke] |
7305 | Kripke's Wittgenstein says meaning 'vanishes into thin air' [Kripke, by Miller,A] |
19270 | If you ask what is in your mind for following the addition rule, meaning just seems to vanish [Kripke] |
17874 | Kripke has a definitional account of kinds, but not of naming [Almog on Kripke] |
16394 | Kripke derives accounts of reference and proper names from assumptions about worlds and essences [Stalnaker on Kripke] |
5822 | The important cause is not between dubbing and current use, but between the item and the speaker's information [Evans on Kripke] |
17033 | We may refer through a causal chain, but still change what is referred to [Kripke] |
4689 | Kripke makes reference a largely social matter, external to the mind of the speaker [Kripke, by McGinn] |
17504 | Kripke's theory is important because it gives a collective account of reference [Kripke, by Putnam] |
17035 | We refer through the community, going back to the original referent [Kripke] |
4956 | A description may fix a reference even when it is not true of its object [Kripke] |
16988 | Descriptive reference shows how to refer, how to identify two things, and how to challenge existence [Kripke, by PG] |
17029 | It can't be necessary that Aristotle had the properties commonly attributed to him [Kripke] |
17032 | Even if Gödel didn't produce his theorems, he's still called 'Gödel' [Kripke] |
11076 | Community implies assertability-conditions rather than truth-conditions semantics [Kripke, by Hanna] |
14893 | Rigid designation creates a puzzle - why do some necessary truths appear to be contingent? [Kripke, by Maciŕ/Garcia-Carpentiro] |
11075 | The sceptical rule-following paradox is the basis of the private language argument [Kripke, by Hanna] |
17056 | Terms for natural kinds are very close to proper names [Kripke] |
4963 | The properties that fix reference are contingent, the properties involving meaning are necessary [Kripke] |
17053 | Gold's atomic number might not be 79, but if it is, could non-79 stuff be gold? [Kripke] |
4964 | 'Cats are animals' has turned out to be a necessary truth [Kripke] |
6765 | Nominal essence may well be neither necessary nor sufficient for a natural kind [Kripke, by Bird] |
9387 | The scientific discovery (if correct) that gold has atomic number 79 is a necessary truth [Kripke] |
17054 | Scientific discoveries about gold are necessary truths [Kripke] |
17057 | Once we've found that heat is molecular motion, then that's what it is, in all possible worlds [Kripke] |
4965 | Science searches basic structures in search of essences [Kripke] |
20624 | Work degrades into heat, but not vice versa [Close] |
20623 | First Law: energy can change form, but is conserved overall [Close] |
20625 | Third Law: total order and minimum entropy only occurs at absolute zero [Close] |
20622 | All motions are relative and ambiguous, but acceleration is the same in all inertial frames [Close] |
20628 | The electric and magnetic are tightly linked, and viewed according to your own motion [Close] |
20635 | The general relativity equations relate curvature in space-time to density of energy-momentum [Close] |
20642 | Photon exchange drives the electro-magnetic force [Close] |
20627 | Electric fields have four basic laws (two by Gauss, one by Ampčre, one by Faraday) [Close] |
20630 | Light isn't just emitted in quanta called photons - light is photons [Close] |
20637 | In general relativity the energy and momentum of photons subjects them to gravity [Close] |
20629 | Electro-magnetic waves travel at light speed - so light is electromagnetism! [Close] |
20632 | In QED, electro-magnetism exists in quantum states, emitting and absorbing electrons [Close] |
20639 | Quantum fields contain continual rapid creation and disappearance [Close] |
20641 | Electrons get their mass by interaction with the Higgs field [Close] |
20631 | Dirac showed how electrons conform to special relativity [Close] |
20626 | Modern theories of matter are grounded in heat, work and energy [Close] |
20633 | The Higgs field is an electroweak plasma - but we don't know what stuff it consists of [Close] |
20640 | Space-time is indeterminate foam over short distances [Close] |
17050 | Tigers may lack all the properties we originally used to identify them [Kripke] |
17051 | The original concept of 'cat' comes from paradigmatic instances [Kripke] |
17049 | 'Tiger' designates a species, and merely looking like the species is not enough [Kripke] |