display all the ideas for this combination of philosophers
4 ideas
13936 | Questions about numbers are answered by analysis, and are analytic, and hence logically true [Carnap] |
Full Idea: For the internal question like 'is there a prime number greater than a hundred?' the answers are found by logical analysis based on the rules for the new expressions. The answers here are analytic, i.e., logically true. | |
From: Rudolph Carnap (Empiricism, Semantics and Ontology [1950], 2) |
8748 | Logical positivists incorporated geometry into logicism, saying axioms are just definitions [Carnap, by Shapiro] |
Full Idea: The logical positivists brought geometry into the fold of logicism. The axioms of, say, Euclidean geometry are simply definitions of primitive terms like 'point' and 'line'. | |
From: report of Rudolph Carnap (Empiricism, Semantics and Ontology [1950]) by Stewart Shapiro - Thinking About Mathematics 5.3 | |
A reaction: If the concept of 'line' is actually created by its definition, then we need to know exactly what (say) 'shortest' means. If we are merely describing a line, then our definition can be 'impredicative', using other accepted concepts. |
9916 | Convention, yes! Arbitrary, no! [Poincaré, by Putnam] |
Full Idea: Poincaré once exclaimed, 'Convention, yes! Arbitrary, no!'. | |
From: report of Henri Poincaré (talk [1901]) by Hilary Putnam - Models and Reality | |
A reaction: An interesting view. It mustn't be assumed that conventions are not rooted in something. Maybe a sort of pragmatism is implied. |
18203 | Avoid non-predicative classifications and definitions [Poincaré] |
Full Idea: Never consider any objects but those capable of being defined in a finite number of word ...Avoid non-predicative classifications and definitions. | |
From: Henri Poincaré (The Logic of Infinity [1909], p.63), quoted by Penelope Maddy - Naturalism in Mathematics II.4 |