26 ideas
11970 | Logicians like their entities to exhibit a maximum degree of purity [Kaplan] |
Full Idea: Logicians like their entities to exhibit a maximum degree of purity. | |
From: David Kaplan (Transworld Heir Lines [1967], p.97) | |
A reaction: An important observation, which explains why the modern obsession with logic has often led us down the metaphysical primrose path to ontological hell. |
11989 | For Russell, expressions dependent on contingent circumstances must be eliminated [Kaplan] |
Full Idea: It is a tenet of Russell's theory that all expressions, and especially definite descriptions, whose denotation is dependent upon contingent circumstances must be eliminated. | |
From: David Kaplan (How to Russell a Frege-Church [1975], II) |
17486 | Supervenience is simply modally robust property co-variance [Hendry] |
Full Idea: Supervenience is not an ontological relationship, being just modally robust property co-variance. | |
From: Robin F. Hendry (Chemistry [2008], 'Ontol') | |
A reaction: I take supervenience to be nothing more than an interesting phenomenon that requires explanation. I suppose Humean Supervenience is a priori metaphysics, since you could hardly explain it. |
11969 | Models nicely separate particulars from their clothing, and logicians often accept that metaphysically [Kaplan] |
Full Idea: The use of models is so natural to logicians ...that they sometimes take seriously what are only artefacts of the model, and adopt a bare particular metaphysics. Why? Because the model so nicely separates the bare particular from its clothing. | |
From: David Kaplan (Transworld Heir Lines [1967], p.97) | |
A reaction: See also Idea 11970. I think this observation is correct, and incredibly important. We need to keep quite separate the notion of identity in conceptual space from our notion of identity in the actual world. The first is bare, the second fat. |
11971 | The simplest solution to transworld identification is to adopt bare particulars [Kaplan] |
Full Idea: If we adopt the bare particular metaphysical view, we have a simple solution to the transworld identification problem: we identify by bare particulars. | |
From: David Kaplan (Transworld Heir Lines [1967], p.98) | |
A reaction: See Ideas 11969 and 11970 on this idea. The problem with bare particulars is that they can change their properties utterly, so that Aristotle in the actual world can be a poached egg in some possible world. We need essences. |
11973 | Unusual people may have no counterparts, or several [Kaplan] |
Full Idea: An extremely vivid person might have no counterparts, and Da Vinci seems to me to have more than one essence. Bertrand Russell is clearly the counterpart of at least three distinct persons in some more plausible world. | |
From: David Kaplan (Transworld Heir Lines [1967], p.100) | |
A reaction: Lewis prefers the notion that there is at most one counterpart, the 'closest' entity is some world. I think he also claims there is at least one counterpart. I like Kaplan's relaxed attitude to these things, which has more explanatory power. |
11972 | Essence is a transworld heir line, rather than a collection of properties [Kaplan] |
Full Idea: I prefer to think of essence as a transworld heir line, rather than as the more familiar collection of properties, because the latter too much suggests the idea of a fixed and final essential description. | |
From: David Kaplan (Transworld Heir Lines [1967], p.100) | |
A reaction: He is sympathetic to the counterpart idea, and close to Lewis's view of essences, as the intersection of counterparts. I like his rebellion against fixed and final descriptions, but am a bit doubtful about his basic idea. Causation should be involved. |
11990 | 'Haecceitism' says that sameness or difference of individuals is independent of appearances [Kaplan] |
Full Idea: The doctrine that we can ask whether this is the same individual in another possible world, and that a common 'thisness' may underlie extreme dissimilarity, or distinct thisnesses may underlie great resemblance, I call 'Haecceitism'. | |
From: David Kaplan (How to Russell a Frege-Church [1975], IV) | |
A reaction: Penelope Mackie emphasises that this doctrine, that each thing is somehow individuated, is not the same as believing in actual haecceities, specific properties which achieve the individuating. |
9668 | 'Haecceitism' is common thisness under dissimilarity, or distinct thisnesses under resemblance [Kaplan] |
Full Idea: That a common 'thisness' may underlie extreme dissimilarity or distinct thisnesses may underlie great resemblance I call 'haecceitism'. (I prefer the pronunciation Hex'-ee-i-tis-m). | |
From: David Kaplan (How to Russell a Frege-Church [1975], IV) | |
A reaction: [odd pronunciation, if 'haec' is pronounced haeek] The view seems to be very unpopular (e.g. with Lewis, Bird and Mumford). But there is an intuitive sense of whether or not two things are identical when they seem dissimilar. |
11991 | If quantification into modal contexts is legitimate, that seems to imply some form of haecceitism [Kaplan] |
Full Idea: If one regards the usual form of quantification into modal and other intensional contexts - modality de re - as legitimate (without special explanations), then one seems committed to some form of haecceitism. | |
From: David Kaplan (How to Russell a Frege-Church [1975], IV) | |
A reaction: That is, modal reference requires fixed identities, irrespective of possible changes in properties. Why could one not refer to objects just as bundles of properties, with some sort of rules about when it ceased to be that particular bundle (keep 60%?)? |
17481 | Nuclear charge (plus laws) explains electron structure and spectrum, but not vice versa [Hendry] |
Full Idea: Given relevant laws of nature (quantum mechanics, the exclusion principle) nuclear charge determines and explains electronic structure and spectroscopic behaviour, but not vice versa. | |
From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
A reaction: I argue that the first necessary condition for essentialism is a direction of explanation, and here we seem to have one. |
11967 | Sentences might have the same sense when logically equivalent - or never have the same sense [Kaplan] |
Full Idea: Among the proposals for conditions under which two sentences have the same ordinary sense, the most liberal (Carnap and Church) is that they be logically equivalent, and the most restrictive (Benson Mates) is that they never have the same sense. | |
From: David Kaplan (Transworld Heir Lines [1967], p.89) | |
A reaction: Personally I would move the discussion to the level of the propositions being expressed before I attempted a solution. |
1757 | The Electra: she knows this man, but not that he is her brother [Eucleides, by Diog. Laertius] |
Full Idea: The 'Electra': Electra knows that Orestes is her brother, but not that this man is Orestes, so she knows and does not know her brother simultaneously. | |
From: report of Eucleides (fragments/reports [c.410 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Eu.4 | |
A reaction: Hence we distinguish 'know of', 'know that' and 'know how'. Hence Russell makes 'knowledge by acquaintance' fundamental, and descriptions come later. |
14080 | Are causal descriptions part of the causal theory of reference, or are they just metasemantic? [Kaplan, by Schaffer,J] |
Full Idea: Kaplan notes that the causal theory of reference can be understood in two quite different ways, as part of the semantics (involving descriptions of causal processes), or as metasemantics, explaining why a term has the referent it does. | |
From: report of David Kaplan (Dthat [1970]) by Jonathan Schaffer - Deflationary Metaontology of Thomasson 1 | |
A reaction: [Kaplan 'Afterthought' 1989] The theory tends to be labelled as 'direct' rather than as 'causal' these days, but causal chains are still at the heart of the story (even if more diffused socially). Nice question. Kaplan takes the meta- version as orthodox. |
14894 | Indexicals have a 'character' (the standing meaning), and a 'content' (truth-conditions for one context) [Kaplan, by Macià/Garcia-Carpentiro] |
Full Idea: Kaplan distinguished two different semantic features of indexical expressions: a 'character' that captures the standing meaning of the expression, and a 'content' that consists of their truth-conditional contribution in particular contexts. | |
From: report of David Kaplan (Demonstratives [1989]) by Macià/Garcia-Carpentiro - Introduction to 'Two-Dimensional Semantics' 1 | |
A reaction: This seems so clearly right that there isn't much to dispute. You can't understand the word 'I' or 'now' if you don't understand both its general purpose, and what it is doing in a particular utterance. But will this generalise to other semantics? |
14700 | 'Content' gives the standard modal profile, and 'character' gives rules for a context [Kaplan, by Schroeter] |
Full Idea: Kaplan sees two aspects of meaning, the 'content', reflecting a thing's modal profile, which is modelled by standard possible worlds semantics, and 'character', giving rules for different contexts. Proper names have constant character; indexicals vary. | |
From: report of David Kaplan (Demonstratives [1989]) by Laura Schroeter - Two-Dimensional Semantics 1.1.1 | |
A reaction: This gives rise to 2-D matrices for representing meaning, and the possible worlds are used twice, for evaluating meaning and then for evaluating context of use. I've always been struck by the two-dimensional semantics of passwords. |
3028 | The chief good is unity, sometimes seen as prudence, or God, or intellect [Eucleides] |
Full Idea: The chief good is unity, which is known by several names, for at one time people call it prudence, at another time God, at another intellect, and so on. | |
From: Eucleides (fragments/reports [c.410 BCE]), quoted by Diogenes Laertius - Lives of Eminent Philosophers 02.9.2 | |
A reaction: So the chief good is what unites and focuses our moral actions. Kant calls that 'the will'. |
17478 | Maybe two kinds are the same if there is no change of entropy on isothermal mixing [Hendry] |
Full Idea: One suggestion is that any two different substance, however alike, exhibit a positive entropy change on mixing. So absence of entropy change on isothermal mixing provides a criterion of sameness of kind. | |
From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
A reaction: [He cites Paul Needham 2000] This sounds nice, because at a more amateur level we can say that stuff is the same if mixing two samples of it produces no difference. I call it the Upanishads Test. |
17484 | Maybe the nature of water is macroscopic, and not in the microstructure [Hendry] |
Full Idea: Some deny that that microstructure is what makes it water; substance identity and difference should be determined instead by macroscopic similarities and differences. | |
From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
A reaction: Very plausible. Is the essential nature of human beings to be found in the structure of our cells? |
17479 | The nature of an element must survive chemical change, so it is the nucleus, not the electrons [Hendry] |
Full Idea: Whatever earns something membership of the extension of 'krypton' must be a property that can survive chemical change and, therefore, the gain and loss of electrons. Hence what makes it krypton must be a nuclear property. | |
From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
A reaction: A very nice illuminating example of essentialism in chemistry. The 'nature' is what survives through change, just like what Aristotle said, innit? |
17485 | Maybe water is the smallest part of it that still counts as water (which is H2O molecules) [Hendry] |
Full Idea: If they do count as water, individual H2O molecules are the smallest items that can qualify as water on their own account. Hydroxyl ions and protons, in contrast, qualify as water only as part of a larger body. | |
From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
A reaction: As Aristotle might say, this is the homoeomerous aspect of water. This is Hendry's own proposal, and seems rather good. |
17482 | Compounds can differ with the same collection of atoms, so structure matters too [Hendry] |
Full Idea: The distinctness of the isomers ethanol (CH3CH2OH, boiling at 78.4°) and dimethyl ether (CH3OCH3, boiling at -24.9°) must lie in their different molecular structures. ...But structure has continuously varying quantities, like bond length and angle. | |
From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
A reaction: [compressed] This seems to imply that what matters is an idealised abstraction of the structure (i.e. its topology), which is a reason for denying that chemistry is reducible to mere physics. |
17483 | Water continuously changes, with new groupings of molecules [Hendry] |
Full Idea: Macroscopic bodies of water are complex and dynamic congeries of different molecular species, in which there is a constant dissociation of individual molecules, re-association of ions, and formation, growth and disassociation of oligomers. | |
From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
A reaction: The point is that these activities are needed to explain the behaviour of water (such as its conductivity). |
17476 | Elements survive chemical change, and are tracked to explain direction and properties [Hendry] |
Full Idea: Elements survive chemical change, and chemical explanations track them from one composite substance to another, thereby explaining both the direction of the chemical change, and the properties of the substances they compose. | |
From: Robin F. Hendry (Chemistry [2008], Intro) | |
A reaction: [The 16,000th idea of this database, entered on Guy Fawkes' Day 2013] |
17477 | Defining elements by atomic number allowed atoms of an element to have different masses [Hendry] |
Full Idea: In 1923 elements were defined as populations of atoms with the same nuclear charge (i.e. atomic number), allowing that atoms of the same element may have different masses. | |
From: Robin F. Hendry (Chemistry [2008], 'Chem') | |
A reaction: The point is that it allowed isotopes of the same element to come under one heading. This is fine for the heavier elements, but a bit dubious for the very light ones (where an isotope makes a bigger difference). |
17480 | Generally it is nuclear charge (not nuclear mass) which determines behaviour [Hendry] |
Full Idea: In general, nuclear charge is the overwhelming determinant of an element's chemical behaviour, while nuclear mass is a negligible factor. | |
From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
A reaction: The exception is the isotopes of very light elements light hydrogen. |