Combining Texts

All the ideas for 'Through the Looking Glass', 'The Logical Syntax of Language' and 'Does Conceivability Entail Possibility?'

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5 ideas

5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence

13342	Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap]
	Full Idea: Carnap proposed to define consequence as 'sentence X follows from the sentences K iff the sentences K and the negation of X are contradictory', but 1) this is intuitively impossible, and 2) consequence would be changed by substituting objects.
	From: comment on Rudolph Carnap (The Logical Syntax of Language [1934], p.88-) by Alfred Tarski - The Concept of Logical Consequence p.414
	A reaction: This seems to be the first step in the ongoing explicit discussion of the nature of logical consequence, which is now seen by many as the central concept of logic. Tarski brings his new tool of 'satisfaction' to bear.

5. Theory of Logic / C. Ontology of Logic / 4. Logic by Convention

13251	Each person is free to build their own logic, just by specifying a syntax [Carnap]
	Full Idea: In logic, there are no morals. Everyone is at liberty to build his own logic, i.e. his own form of language. All that is required is that he must state his methods clearly, and give syntactical rules instead of philosophical arguments.
	From: Rudolph Carnap (The Logical Syntax of Language [1934], §17), quoted by JC Beall / G Restall - Logical Pluralism 7.3
	A reaction: This is understandable, but strikes me as close to daft relativism. If I specify a silly logic, I presume its silliness will be obvious. By what criteria? I say the world dictates the true logic, but this is a minority view.

7. Existence / A. Nature of Existence / 3. Being / e. Being and nothing

21982	I only wish I had such eyes as to see Nobody! It's as much as I can do to see real people. [Carroll,L]
	Full Idea: "I see nobody on the road," said Alice. - "I only wish I had such eyes," the King remarked. ..."To be able to see Nobody! ...Why, it's as much as I can do to see real people."
	From: Lewis Carroll (C.Dodgson) (Through the Looking Glass [1886], p.189), quoted by A.W. Moore - The Evolution of Modern Metaphysics 07.7
	A reaction: [Moore quotes this, inevitably, in a chapter on Hegel] This may be a better candidate for the birth of philosophy of language than Frege's Groundwork.

10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible

16473	Modal Rationalism: conceivability gives a priori access to modal truths [Chalmers, by Stalnaker]
	Full Idea: Chalmers' 'modal rationalist' is one who identifies what is possible with what is conceivable; the central claim of the doctrine is that we have a priori access to modal truth.
	From: report of David J.Chalmers (Does Conceivability Entail Possibility? [2002]) by Robert C. Stalnaker - Mere Possibilities 5
	A reaction: A helpful clarification, as I can now see how hopelessly and utterly wrong Chalmers is (about almost everything), and I find my confidence in any sort of genuine a priori knowledge (except of conceptual relations) dwindling by the minute.

19258	Evaluate primary possibility from some world, and secondary possibility from this world [Chalmers, by Vaidya]
	Full Idea: For Chalmers, that water is XYZ is 'primary possible' (a priori, or conceptually), because it is true in some world considered as actual. It is 'secondary impossible', when it is evaluated from the Earth as actual.
	From: report of David J.Chalmers (Does Conceivability Entail Possibility? [2002]) by Anand Vaidya - Understanding and Essence Intro
	A reaction: [compressed] This is Chalmers' account of how we can know possibility from conceivability, via his two-dimensional semantics (see alphabetical themes).