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All the ideas for 'Clitophon', 'Merely Possible Propositions' and 'On the General Idea of Proof Theory'

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5 ideas

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

13827	Logical consequence isn't a black box (Tarski's approach); we should explain how arguments work [Prawitz]
	Full Idea: Defining logical consequence in the way Tarski does is a rather meagre result, treating an argument as a black box, observing input and output, while disregarding inner structure. We should define logical consequence on the basis of valid arguments.
	From: Dag Prawitz (On the General Idea of Proof Theory [1974], §2)

5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models

13826	Model theory looks at valid sentences and consequence, but not how we know these things [Prawitz]
	Full Idea: In model theory, which has dominated the last decades, one concentrates on logically valid sentences, and what follows logically from what, but one disregards questions concerning how we know these things.
	From: Dag Prawitz (On the General Idea of Proof Theory [1974], §1)

9. Objects / A. Existence of Objects / 4. Impossible objects

14617	Predicates can't apply to what doesn't exist [Stalnaker]
	Full Idea: Nothing can be predicated of something which does not exist.
	From: Robert C. Stalnaker (Merely Possible Propositions [2010], p.28)
	A reaction: [He says he is 'agreeing with Plantinga' on this] This seems very puzzling, as you can obviously say that dragons do not exist, but they breathe fire. Why can't you attach predicates to hypothetical objects?

19. Language / D. Propositions / 3. Concrete Propositions

14616	A 'Russellian proposition' is an ordered sequence of individual, properties and relations [Stalnaker]
	Full Idea: A 'Russellian proposition' is an ordered sequence containing the individual, along with properties and relations.
	From: Robert C. Stalnaker (Merely Possible Propositions [2010], p.22)
	A reaction: Since Russell took properties and relations to be features of reality, this made the whole proposition a feature of reality. This is utterly different from what I understand by the word 'proposition', which is a feature of thought, not of the world.

22. Metaethics / B. Value / 2. Values / f. Altruism

1590	The just man does not harm his enemies, but benefits everyone [Plato]
	Full Idea: First, Socrates, you told me justice is harming your enemies and helping your friends. But later it seemed that the just man, since everything he does is for someone's benefit, never harms anyone.
	From: Plato (Clitophon [c.372 BCE], 410b)
	A reaction: Socrates certainly didn't subscribe to the first view, which is the traditional consensus in Greek culture. In general Socrates agreed with the views later promoted by Jesus.