14 ideas
7785 | The use of plurals doesn't commit us to sets; there do not exist individuals and collections [Boolos] |
Full Idea: We should abandon the idea that the use of plural forms commits us to the existence of sets/classes… Entities are not to be multiplied beyond necessity. There are not two sorts of things in the world, individuals and collections. | |
From: George Boolos (To be is to be the value of a variable.. [1984]), quoted by Henry Laycock - Object | |
A reaction: The problem of quantifying over sets is notoriously difficult. Try http://plato.stanford.edu/entries/object/index.html. |
10699 | Does a bowl of Cheerios contain all its sets and subsets? [Boolos] |
Full Idea: Is there, in addition to the 200 Cheerios in a bowl, also a set of them all? And what about the vast number of subsets of Cheerios? It is haywire to think that when you have some Cheerios you are eating a set. What you are doing is: eating the Cheerios. | |
From: George Boolos (To be is to be the value of a variable.. [1984], p.72) | |
A reaction: In my case Boolos is preaching to the converted. I am particularly bewildered by someone (i.e. Quine) who believes that innumerable sets exist while 'having a taste for desert landscapes' in their ontology. |
9390 | Logic guides thinking, but it isn't a substitute for it [Rumfitt] |
Full Idea: Logic is part of a normative theory of thinking, not a substitute for thinking. | |
From: Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.13) | |
A reaction: There is some sort of logicians' dream, going back to Leibniz, of a reasoning engine, which accepts propositions and outputs inferences. I agree with this idea. People who excel at logic are often, it seems to me, modest at philosophy. |
10225 | Monadic second-order logic might be understood in terms of plural quantifiers [Boolos, by Shapiro] |
Full Idea: Boolos has proposed an alternative understanding of monadic, second-order logic, in terms of plural quantifiers, which many philosophers have found attractive. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Philosophy of Mathematics 3.5 |
10736 | Boolos showed how plural quantifiers can interpret monadic second-order logic [Boolos, by Linnebo] |
Full Idea: In an indisputable technical result, Boolos showed how plural quantifiers can be used to interpret monadic second-order logic. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984], Intro) by Øystein Linnebo - Plural Quantification Exposed Intro |
10780 | Any sentence of monadic second-order logic can be translated into plural first-order logic [Boolos, by Linnebo] |
Full Idea: Boolos discovered that any sentence of monadic second-order logic can be translated into plural first-order logic. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984], §1) by Øystein Linnebo - Plural Quantification Exposed p.74 |
10697 | Identity is clearly a logical concept, and greatly enhances predicate calculus [Boolos] |
Full Idea: Indispensable to cross-reference, lacking distinctive content, and pervading thought and discourse, 'identity' is without question a logical concept. Adding it to predicate calculus significantly increases the number and variety of inferences possible. | |
From: George Boolos (To be is to be the value of a variable.. [1984], p.54) | |
A reaction: It is not at all clear to me that identity is a logical concept. Is 'existence' a logical concept? It seems to fit all of Boolos's criteria? I say that all he really means is that it is basic to thought, but I'm not sure it drives the reasoning process. |
13671 | Second-order quantifiers are just like plural quantifiers in ordinary language, with no extra ontology [Boolos, by Shapiro] |
Full Idea: Boolos proposes that second-order quantifiers be regarded as 'plural quantifiers' are in ordinary language, and has developed a semantics along those lines. In this way they introduce no new ontology. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Foundations without Foundationalism 7 n32 | |
A reaction: This presumably has to treat simple predicates and relations as simply groups of objects, rather than having platonic existence, or something. |
10267 | We should understand second-order existential quantifiers as plural quantifiers [Boolos, by Shapiro] |
Full Idea: Standard second-order existential quantifiers pick out a class or a property, but Boolos suggests that they be understood as a plural quantifier, like 'there are objects' or 'there are people'. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Philosophy of Mathematics 7.4 | |
A reaction: This idea has potential application to mathematics, and Lewis (1991, 1993) 'invokes it to develop an eliminative structuralism' (Shapiro). |
10698 | Plural forms have no more ontological commitment than to first-order objects [Boolos] |
Full Idea: Abandon the idea that use of plural forms must always be understood to commit one to the existence of sets of those things to which the corresponding singular forms apply. | |
From: George Boolos (To be is to be the value of a variable.. [1984], p.66) | |
A reaction: It seems to be an open question whether plural quantification is first- or second-order, but it looks as if it is a rewriting of the first-order. |
7806 | Boolos invented plural quantification [Boolos, by Benardete,JA] |
Full Idea: Boolos virtually patented the new device of plural quantification. | |
From: report of George Boolos (To be is to be the value of a variable.. [1984]) by José A. Benardete - Logic and Ontology | |
A reaction: This would be 'there are some things such that...' |
10700 | First- and second-order quantifiers are two ways of referring to the same things [Boolos] |
Full Idea: Ontological commitment is carried by first-order quantifiers; a second-order quantifier needn't be taken to be a first-order quantifier in disguise, having special items, collections, as its range. They are two ways of referring to the same things. | |
From: George Boolos (To be is to be the value of a variable.. [1984], p.72) | |
A reaction: If second-order quantifiers are just a way of referring, then we can see first-order quantifiers that way too, so we could deny 'objects'. |
9389 | Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt] |
Full Idea: Vagueness in respect of membership is consistency with determinacy of the set's identity, so long as a set's identity is taken to consist, not in its having such-and-such members, but in its being the extension of a concept. | |
From: Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.5) | |
A reaction: I find this view of sets much more appealing than the one that identifies a set with its members. The empty set is less of a problem, as well as non-existents. Logicians prefer the extensional view because it is tidy. |
22456 | Maybe virtues conflict with each other, if some virtue needs a vice for its achievement [Foot] |
Full Idea: Maybe so far from forming a unity ...., the virtues actually conflict with each other: that is, if someone has one of them he inevitably fails to have some other. ...Maybe he a man can only be good in one way be being bad in another. | |
From: Philippa Foot (Moral Realism and Moral Dilemma [1983], p.57) | |
A reaction: She suggests the self-loathing needed to rein in evil desires. She cites Nietzsche having a similar thought. Presumably the ideal virtuous person has no such conflicts, and the self-loathing undermines eudaimonia. Unity in theory but not in practice? |