display all the ideas for this combination of texts
3 ideas
4971 | I don't use 'subject' and 'predicate' in my way of representing a judgement [Frege] |
Full Idea: A distinction of subject and predicate finds no place in my way of representing a judgement. | |
From: Gottlob Frege (Begriffsschrift [1879], §03) | |
A reaction: Perhaps this sentence could be taken as the beginning of modern analytical philosophy. The old view doesn't seem to me entirely redundant - merely replaced by a much more detailed analysis of what makes a 'subject' and what makes a 'predicate'. |
17745 | For Frege, 'All A's are B's' means that the concept A implies the concept B [Frege, by Walicki] |
Full Idea: 'All A's are B's' meant for Frege that the concept A implies the concept B, or that to be A implies also to be B. Moreover this applies to arbitrary x which happens to be A. | |
From: report of Gottlob Frege (Begriffsschrift [1879]) by Michal Walicki - Introduction to Mathematical Logic History D.2 | |
A reaction: This seems to hit the renate/cordate problem. If all creatures with hearts also have kidneys, does that mean that being enhearted logically implies being kidneyfied? If all chimps are hairy, is that a logical requirement? Is inclusion implication? |
15544 | If what is actual might have been impossible, we need S4 modal logic [Armstrong, by Lewis] |
Full Idea: Armstrong says what is actual (namely a certain roster of universals) might have been impossible. Hence his modal logic is S4, without the 'Brouwersche Axiom'. | |
From: report of David M. Armstrong (A Theory of Universals [1978]) by David Lewis - Armstrong on combinatorial possibility 'The demand' | |
A reaction: So p would imply possibly-not-possibly-p. |