Combining Texts

All the ideas for 'fragments/reports', 'On the General Idea of Proof Theory' and 'A world of truthmakers?'

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4 ideas

3. Truth / B. Truthmakers / 6. Making Negative Truths
If it were true that nothing at all existed, would that have a truthmaker? [Lewis]
     Full Idea: If there was absolutely nothing at all, then it would have been true that there was nothing. Would there have been a truthmaker for this truth?
     From: David Lewis (A world of truthmakers? [1998], p.220)
     A reaction: This is a problem for Lewis's own claim that 'truth supervenes on being', as well as the more restricted truthmakers invoked by Armstrong.
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
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
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)
13. Knowledge Criteria / E. Relativism / 2. Knowledge as Convention
By nature people are close to one another, but culture drives them apart [Hippias]
     Full Idea: I regard you all as relatives - by nature, not by convention. By nature like is akin to like, but convention is a tyrant over humankind and often constrains people to act contrary to nature.
     From: Hippias (fragments/reports [c.430 BCE]), quoted by Plato - Protagoras 337c8