5 ideas
18491 | The idea of 'making' can be mere conceptual explanation (like 'because') [Künne] |
Full Idea: If we say 'being a child of our parent's sibling makes him your first cousin', that can be paraphrased using 'because', and this is the 'because' of conceptual explanation: the second part elucidates the sense of the first part. | |
From: Wolfgang Künne (Conceptions of Truth [2003], 3.5.2) | |
A reaction: Fans of truth-making are certainly made uncomfortable by talk of 'what makes this a good painting' or 'this made my day'. They need a bit more sharpness to the concept of 'making' a truth. |
13418 | The old problems with the axiom of choice are probably better ascribed to the law of excluded middle [Parsons,C] |
Full Idea: The difficulties historically attributed to the axiom of choice are probably better ascribed to the law of excluded middle. | |
From: Charles Parsons (Review of Tait 'Provenance of Pure Reason' [2009], §2) | |
A reaction: The law of excluded middle was a target for the intuitionists, so presumably the debate went off in that direction. |
18244 | I say the irrational is not the cut itself, but a new creation which corresponds to the cut [Dedekind] |
Full Idea: Of my theory of irrationals you say that the irrational number is nothing else than the cut itself, whereas I prefer to create something new (different from the cut), which corresponds to the cut. We have the right to claim such a creative power. | |
From: Richard Dedekind (Letter to Weber [1888], 1888 Jan), quoted by Stewart Shapiro - Philosophy of Mathematics 5.4 | |
A reaction: Clearly a cut will not locate a unique irrational number, so something more needs to be done. Shapiro remarks here that for Dedekind numbers are objects. |
13419 | If functions are transfinite objects, finitists can have no conception of them [Parsons,C] |
Full Idea: The finitist may have no conception of function, because functions are transfinite objects. | |
From: Charles Parsons (Review of Tait 'Provenance of Pure Reason' [2009], §4) | |
A reaction: He is offering a view of Tait's. Above my pay scale, but it sounds like a powerful objection to the finitist view. Maybe there is a finitist account of functions that could be given? |
13417 | If a mathematical structure is rejected from a physical theory, it retains its mathematical status [Parsons,C] |
Full Idea: If experience shows that some aspect of the physical world fails to instantiate a certain mathematical structure, one will modify the theory by sustituting a different structure, while the original structure doesn't lose its status as part of mathematics. | |
From: Charles Parsons (Review of Tait 'Provenance of Pure Reason' [2009], §2) | |
A reaction: This seems to be a beautifully simple and powerful objection to the Quinean idea that mathematics somehow only gets its authority from physics. It looked like a daft view to begin with, of course. |