5 ideas
14286 | In nearby worlds where A is true, 'if A,B' is true or false if B is true or false [Stalnaker] |
Full Idea: Consider a possible world in which A is true and otherwise differs minimally from the actual world. 'If A, then B' is true (false) just in case B is true (false) in that possible world. | |
From: Robert C. Stalnaker (A Theory of Conditionals [1968], p.34), quoted by Dorothy Edgington - Conditionals (Stanf) 4.1 | |
A reaction: This is the first proposal to give a possible worlds semantics for conditional statements. Edgington observes that worlds which are nearby for me may not be nearby for you. |
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] |
19440 | How do you know you have conceived a thing deeply enough to assess its possibility? [Vaidya] |
Full Idea: The main issue with learning possibility from conceivability concerns how we can be confident that we have conceived things to the relevant level of depth required for the scenario to actually be a presentation or manifestation of a genuine possibility. | |
From: Anand Vaidya (The Epistemology of Modality [2015], 1.2.2) | |
A reaction: [He cites Van Inwagen 1998 for this idea] The point is that ignorant imagination can conceive of all sorts of absurd things which are seen to be impossible when enough information is available. We can hardly demand a criterion for this. |
14285 | A possible world is the ontological analogue of hypothetical beliefs [Stalnaker] |
Full Idea: A possible world is the ontological analogue of a stock of hypothetical beliefs. | |
From: Robert C. Stalnaker (A Theory of Conditionals [1968], p.34), quoted by Dorothy Edgington - Conditionals (Stanf) 4.1 | |
A reaction: Sounds neat and persuasive. What is the ontological analogue of a stock of hopes? Heaven! |
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. |