Combining Texts

Ideas for 'Essays on Intellectual Powers: Conception', 'Remarks on the definition and nature of mathematics' and 'The Trouble with Possible Worlds'

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4 ideas

10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / b. Conceivable but impossible
Impossibilites are easily conceived in mathematics and geometry [Reid, by Molnar]
     Full Idea: Reid pointed out how easily conceivable mathematical and geometric impossibilities are.
     From: report of Thomas Reid (Essays on Intellectual Powers 4: Conception [1785], IV.III) by George Molnar - Powers 11.3
     A reaction: The defence would be that you have to really really conceive them, and the only way the impossible can be conceived is by blurring it at the crucial point, or by claiming to conceive more than you actually can
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Treating possible worlds as mental needs more actual mental events [Lycan]
     Full Idea: A mentalistic approach to possible worlds is daunted by the paucity of actual mental events.
     From: William Lycan (The Trouble with Possible Worlds [1979], 09)
     A reaction: Why do they have to be actual, any more than memories have to be conscious? The mental events just need to be available when you need them. They are never all required simultaneously. This isn't mathematical logic!
Possible worlds must be made of intensional objects like propositions or properties [Lycan]
     Full Idea: I believe the only promising choice of actual entities to serve as 'worlds' is that of sets of intensional objects, such as propositions or properties with stipulated interrelations.
     From: William Lycan (The Trouble with Possible Worlds [1979], 12)
     A reaction: This is mainly in response to Lewis's construction of them out of actual concrete objects. It strikes me as a bogus problem. It is just a convenient way to think precisely about possibilities, and occasionally outruns our mental capacity.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / c. Worlds as propositions
If 'worlds' are sentences, and possibility their consistency, consistency may rely on possibility [Lycan]
     Full Idea: If a 'world' is understood as a set of sentences, then possibility may be understood as consistency, ...but this seems circular, in that 'consistency' of sentences cannot adequately be defined save in terms of possibility.
     From: William Lycan (The Trouble with Possible Worlds [1979], 09)
     A reaction: [Carnap and Hintikka propose the view, Lewis 'Counterfactuals' p.85 objects] Worlds as sentences is not, of course, the same as worlds as propositions. There is a lot of circularity around in 'possible' worlds.