10 ideas
15544 | If what is actual might have been impossible, we need S4 modal logic [Armstrong, by Lewis] |
Full Idea: Armstrong says what is actual (namely a certain roster of universals) might have been impossible. Hence his modal logic is S4, without the 'Brouwersche Axiom'. | |
From: report of David M. Armstrong (A Theory of Universals [1978]) by David Lewis - Armstrong on combinatorial possibility 'The demand' | |
A reaction: So p would imply possibly-not-possibly-p. |
10245 | One geometry cannot be more true than another [Poincaré] |
Full Idea: One geometry cannot be more true than another; it can only be more convenient. | |
From: Henri Poincaré (Science and Method [1908], p.65), quoted by Stewart Shapiro - Philosophy of Mathematics | |
A reaction: This is the culminating view after new geometries were developed by tinkering with Euclid's parallels postulate. |
7024 | Properties are universals, which are always instantiated [Armstrong, by Heil] |
Full Idea: Armstrong takes properties to be universals, and believes there are no 'uninstantiated' universals. | |
From: report of David M. Armstrong (A Theory of Universals [1978]) by John Heil - From an Ontological Point of View §9.3 | |
A reaction: At first glance this, like many theories of universals, seems to invite Ockham's Razor. If they are always instantiated, perhaps we should perhaps just try to talk about the instantiations (i.e. tropes), and skip the universal? |
9478 | Even if all properties are categorical, they may be denoted by dispositional predicates [Armstrong, by Bird] |
Full Idea: Armstrong says all properties are categorical, but a dispositional predicate may denote such a property; the dispositional predicate denotes the categorical property in virtue of the dispositional role it happens, contingently, to play in this world. | |
From: report of David M. Armstrong (A Theory of Universals [1978]) by Alexander Bird - Nature's Metaphysics 3.1 | |
A reaction: I favour the fundamentality of the dispositional rather than the categorical. The world consists of powers, and we find ourselves amidst their categorical expressions. I could be persuaded otherwise, though! |
10729 | Universals explain resemblance and causal power [Armstrong, by Oliver] |
Full Idea: Armstrong thinks universals play two roles, namely grounding objective resemblances and grounding causal powers. | |
From: report of David M. Armstrong (A Theory of Universals [1978]) by Alex Oliver - The Metaphysics of Properties 11 | |
A reaction: Personally I don't think universals explain anything at all. They just add another layer of confusion to a difficult problem. Oliver objects that this seems a priori, contrary to Armstrong's principle in Idea 10728. |
4031 | It doesn't follow that because there is a predicate there must therefore exist a property [Armstrong] |
Full Idea: I suggest that we reject the notion that just because the predicate 'red' applies to an open class of particulars, therefore there must be a property, redness. | |
From: David M. Armstrong (A Theory of Universals [1978], p.8), quoted by DH Mellor / A Oliver - Introduction to 'Properties' §6 | |
A reaction: At last someone sensible (an Australian) rebuts that absurd idea that our ontology is entirely a feature of our language |
10024 | The type-token distinction is the universal-particular distinction [Armstrong, by Hodes] |
Full Idea: Armstrong conflates the type-token distinction with that between universals and particulars. | |
From: report of David M. Armstrong (A Theory of Universals [1978], xiii,16/17) by Harold Hodes - Logicism and Ontological Commits. of Arithmetic 147 n23 | |
A reaction: This seems quite reasonable, even if you don’t believe in the reality of universals. I'm beginning to think we should just use the term 'general' instead of 'universal'. 'Type' also seems to correspond to 'set', with the 'token' as the 'member'. |
10728 | A thing's self-identity can't be a universal, since we can know it a priori [Armstrong, by Oliver] |
Full Idea: Armstrong says that if it can be proved a priori that a thing falls under a certain universal, then there is no such universal - and hence there is no universal of a thing being identical with itself. | |
From: report of David M. Armstrong (A Theory of Universals [1978], II p.11) by Alex Oliver - The Metaphysics of Properties 11 | |
A reaction: This is a distinctively Armstrongian view, based on his belief that universals must be instantiated, and must be discoverable a posteriori, as part of science. I'm baffled by self-identity, but I don't think this argument does the job. |
13766 | 'If' is the same as 'given that', so the degrees of belief should conform to probability theory [Ramsey, by Ramsey] |
Full Idea: Ramsey suggested that 'if', 'given that' and 'on the supposition that' come to the same thing, and that the degrees of belief in the antecedent should then conform to probability theory. | |
From: report of Frank P. Ramsey (Truth and Probability [1926]) by Frank P. Ramsey - Law and Causality B | |
A reaction: [compressed] |
19143 | Ramsey gave axioms for an uncertain agent to decide their preferences [Ramsey, by Davidson] |
Full Idea: Ramsey gave an axiomatic treatment of preference in the face of uncertainty, when applied to a particular agent. | |
From: report of Frank P. Ramsey (Truth and Probability [1926]) by Donald Davidson - Truth and Predication 2 | |
A reaction: This is evidently the beginnings of Bayesian decision theory. |