| 18442 | You only know an attribute if you know what things have it [Quine] |
| Full Idea: May we not say that you know an attribute only insofar as you know what things have it? | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.106) | |
| A reaction: Simple, and the best defence of class nominalism (a very implausible theory) which I have encountered. Do I have to know all the things? Do I not know 'red' if I don't know tomatoes have it? |
| 8504 | Quine aims to deal with properties by the use of eternal open sentences, or classes [Quine, by Devitt] |
| Full Idea: Quine is not an 'ostrich', because his strategy for dealing with property sentences is clear enough: all talk of attributes is to be dispensed with in favour of talk of eternal open sentences or talk of classes. | |
| From: report of Willard Quine (Word and Object [1960], §43) by Michael Devitt - 'Ostrich Nominalism' or 'Mirage Realism'? p.100 | |
| A reaction: [See p.209 'Word and Object'] The proposal seems to be that a property like being-human (a category) would be dealt with by classes, and qualitative properties would be dealt with simply as predicates. I like the split, and the first half, not the second. |
| 7970 | Quine is committed to sets, but is more a Class Nominalist than a Platonist [Quine, by Macdonald,C] |
| Full Idea: Armstrong dubs Quine an 'Ostrich Nominalist' (what problem??), but Quine calls himself a Platonist, because he is committed to classes or sets as well as particulars. He is not an extreme nominalist, and might best be called a Class Nominalist. | |
| From: report of Willard Quine (works [1961], Ch.6 n15) by Cynthia Macdonald - Varieties of Things | |
| A reaction: For someone as ontologically austere as Quine to show 'commitment' to sets deserves some recognition. If he wants to be a Platonist, I say that's fine. What on earth is a set, apart from its members? |
| 8531 | In most sets there is no property common to all the members [Armstrong] |
| Full Idea: Most sets are uninteresting because they are utterly heterogeneous, that is, the members have nothing in common. For most sets there is no common property F, such that the set is the set of all the Fs. | |
| From: David M. Armstrong (Properties [1992], §1) | |
| A reaction: One might link the interesting sets together by resemblance, without invoking the actual existence of an item F which all the members carry (like freemasons' briefcases). Personally I am only really interested in 'natural' sets. |
| 18371 | The class of similar things is much too big a truthmaker for the feature of a particular [Armstrong] |
| Full Idea: For a Class Nominalist 'the class of all 4-kilo objects' is the truthmaker for the truth that the particular has just that mass. Yet this looks far too big! Would not the object still be four kilos even if the other members of the class had never existed? | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 04.2) | |
| A reaction: This seems so obvious to me as to be hardly worth saying. To identify redness with the class of red entities just seems crazy. Why do they belong in that class? Armstrong is illustrating the value of the truthmaker idea in philosophy. |
| 4434 | 'Class Nominalism' says that properties or kinds are merely membership of a set (e.g. of white things) [Armstrong] |
| Full Idea: Class Nominalists substitute classes or sets for properties or kinds, so that being white is just being a member of the set of white things; relations are treated as ordered sets. | |
| From: David M. Armstrong (Universals [1995], p.503) | |
| A reaction: This immediately seems wrong, because it invites the question of why something is a member of a set (unless membership is arbitrary and whimsical - which it usually isn't). |
| 4435 | 'Class Nominalism' cannot explain co-extensive properties, or sets with random members [Armstrong] |
| Full Idea: Class Nominalism cannot explain co-extensive properties (which qualify the same things), and also a random (non-natural) set has particulars with nothing in common, thus failing to capture an essential feature of a general property. | |
| From: David M. Armstrong (Universals [1995], p.503) | |
| A reaction: These objections strike me as conclusive, since we can assign things to a set quite arbitrarily, so membership of a set may signify no shared property at all (except, say, 'owned by me', which is hardly a property). |
| 4436 | 'Class Nominalism' may explain properties if we stick to 'natural' sets, and ignore random ones [Armstrong] |
| Full Idea: Class Nominalism can be defended (by Quinton) against the problem of random sets (with nothing in common), by giving an account of properties in terms of 'natural' classes, where 'natural' comes in degrees, but is fundamental and unanalysable. | |
| From: David M. Armstrong (Universals [1995], p.503) | |
| A reaction: This still seems to beg the question, because you still have to decide whether two things have anything 'naturally' in common before you assign them to a set. |
| 8550 | Triangular and trilateral are coextensive, but different concepts; but powers and properties are the same [Shoemaker] |
| Full Idea: It is natural to say that 'being triangular' and 'being trilateral', though necessarily coextensive, are different properties. But what are distinct are the concepts and meanings. If properties are not meanings of predicates, these are identical. | |
| From: Sydney Shoemaker (Causality and Properties [1980], §04) | |
| A reaction: A good test example. Being renate (kidney) and being cordate (heart) are different, because being cordate produces a thumping noise. Shoemaker's example is pretty much Phosphorus/Hesperus. |
| 20339 | Classes rarely share properties with their members - unlike universals and types [Wollheim] |
| Full Idea: Classes can share properties with their members (e.g. the class of big things is big), but this is very rare. ....In the case of both universals and types, there will be shared properties. Red things can be exhilarating, and so can redness. | |
| From: Richard Wollheim (Art and Its Objects [1968], 92) | |
| A reaction: 'Exhilarating' is an extrinsic property, so not the best illustration. This is interesting, but would need checking with a wide range of examples. (Too busy for that right now) |
| 15438 | We can add a primitive natural/unnatural distinction to class nominalism [Lewis] |
| Full Idea: To class nominalism we can add a primitive distinction between natural and unnatural classes. | |
| From: David Lewis (Against Structural Universals [1986], 'Why believe') | |
| A reaction: Lewis explores this elsewhere, but this looks like a very complex concept to play the role of a 'primitive'. Human conventions seem to be parts of nature. |
| 8570 | To have a property is to be a member of a class, usually a class of things [Lewis] |
| Full Idea: To have a property is to be a member of a class, usually a class of things. (Note: this resembles the doctrine of Class Nominalism, but I do not claim to solve the One Over Many problem by this means, far from it). | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop') | |
| A reaction: Lewis remains neutral about the traditional question of whether universals exist. What does he mean by "is" in his assertion? Identity, predication or class membership? I think Lewis is open to many of the objections to Class Nominalism. |
| 8574 | Class Nominalism and Resemblance Nominalism are pretty much the same [Lewis] |
| Full Idea: Moderate Class Nominalism and Resemblance Nominalism (in its present form) seem to me to be a single theory presented in different styles. | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop' n9) | |
| A reaction: Lewis has earlier endorsed a cautious form of Class Nominalism (Idea 8570). Which comes first, having a resemblance, or being in a class? Quine seems to make resemblance basic (Idea 8486), but Lewis seems to make the class basic (Idea 8572). |
| 7032 | Objects join sets because of properties; the property is not bestowed by set membership [Heil] |
| Full Idea: The set of red objects is the set of objects possessing a property: being red. Objects are members of the set in virtue of possessing this property; they do not possess the property in virtue of belonging to the set. | |
| From: John Heil (From an Ontological Point of View [2003], 12.2) | |
| A reaction: This seems to be a very effective denial of the claim that universals are sets. However, if 'being a Londoner' counts as a property, you can only have it by joining the London set. Being tall is more fundamental than being a Londoner. |
| 4233 | If 'blueness' is a set of particulars, there is danger of circularity, or using universals, in identifying the set [Lowe] |
| Full Idea: If sets are particulars, a nominalist may say that 'blueness' is a set of particulars, but which set? If the particulars 'are blue' this threatens circularity - though resemblance is usually appealed to to avoid this. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.355) | |
| A reaction: This supports my suspicion that nominalism is superficially attractive and 'scientific', but when you dig deep into it the theory won't get off the ground without universals. |
| 4471 | We should abandon the concept of a property since (unlike sets) their identity conditions are unclear [Moreland] |
| Full Idea: Some argue that compared to sets, the identity conditions for properties are obscure, and so properties, including realist depictions of them, should be rejected. | |
| From: J.P. Moreland (Universals [2001], Ch.6) | |
| A reaction: I have never thought that difficulty in precisely identifying something was a good reason for denying its existence. Consider low morale in a work force. 2nd thoughts: I like this! |
| 14597 | Natural Class Nominalism says there are primitive classes of things resembling in one respect [Dorr] |
| Full Idea: Natural Class Nominalists take as primitive the notion of a 'natural' class - a class of things that all resemble one another in some one respect and resemble nothing else in that respect. | |
| From: Cian Dorr (There Are No Abstract Objects [2008], 4) | |
| A reaction: Dorr rejects this view because he doesn't believe in 'classes'. How committed to classes do you have to be before you are permitted to talk about them? All vocabulary (such as 'resemble') seems metaphysically tainted in this area. |