13 ideas
| 20955 | Art can make reason more all-inclusive, by articulating what seemed inexpressible [Bowie] |
| Full Idea: The early German Romantics argued that art pointed to a more all-inclusive conception of reason, which can offer ways of articulating what is not conceptually accessible. | |
| From: Andrew Bowie (Introduction to German Philosophy [2003], 5 'Reason') | |
| A reaction: [This is Novalis, F.Schlegel, Schleiermacher, and Hölderlin] I'm in favour of expanding reason, to include assessment of situations and coherence, rather than just stepwise reasoning. Not sure that art 'articulates' something new. |
| 23445 | Naïve set theory says any formula defines a set, and coextensive sets are identical [Linnebo] |
| Full Idea: Naïve set theory is based on the principles that any formula defines a set, and that coextensive sets are identical. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 4.2) | |
| A reaction: The second principle is a standard axiom of ZFC. The first principle causes the trouble. |
| 17743 | De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki] |
| Full Idea: In 1846 De Morgan introduced the enormously influential notion of a possibly arbitrary and stipulated 'universe of discourse'. It replaced Boole's original - and metaphysically a bit suspect - universe of 'all things'. | |
| From: report of Augustus De Morgan (works [1846]) by Michal Walicki - Introduction to Mathematical Logic History D.1.1 | |
| A reaction: This not only brings formal logic under control, but also reflects normal talk, because there is always an explicit or implicit domain of discourse when we talk. Of virtually any conversation, you can say what it is 'about'. |
| 23447 | In classical semantics singular terms refer, and quantifiers range over domains [Linnebo] |
| Full Idea: In classical semantics the function of singular terms is to refer, and that of quantifiers, to range over appropriate domains of entities. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 7.1) |
| 23443 | The axioms of group theory are not assertions, but a definition of a structure [Linnebo] |
| Full Idea: Considered in isolation, the axioms of group theory are not assertions but comprise an implicit definition of some abstract structure, | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 3.5) | |
| A reaction: The traditional Euclidean approach is that axioms are plausible assertions with which to start. The present idea sums up the modern approach. In the modern version you can work backwards from a structure to a set of axioms. |
| 23444 | To investigate axiomatic theories, mathematics needs its own foundational axioms [Linnebo] |
| Full Idea: Mathematics investigates the deductive consequences of axiomatic theories, but it also needs its own foundational axioms in order to provide models for its various axiomatic theories. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 4.1) | |
| A reaction: This is a problem which faces the deductivist (if-then) approach. The deductive process needs its own grounds. |
| 23446 | You can't prove consistency using a weaker theory, but you can use a consistent theory [Linnebo] |
| Full Idea: If the 2nd Incompleteness Theorem undermines Hilbert's attempt to use a weak theory to prove the consistency of a strong one, it is still possible to prove the consistency of one theory, assuming the consistency of another theory. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 4.6) | |
| A reaction: Note that this concerns consistency, not completeness. |
| 23448 | Mathematics is the study of all possible patterns, and is thus bound to describe the world [Linnebo] |
| Full Idea: Philosophical structuralism holds that mathematics is the study of abstract structures, or 'patterns'. If mathematics is the study of all possible patterns, then it is inevitable that the world is described by mathematics. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 11.1) | |
| A reaction: [He cites the physicist John Barrow (2010) for this] For me this is a major idea, because the concept of a pattern gives a link between the natural physical world and the abstract world of mathematics. No platonism is needed. |
| 23441 | Logical truth is true in all models, so mathematical objects can't be purely logical [Linnebo] |
| Full Idea: Modern logic requires that logical truths be true in all models, including ones devoid of any mathematical objects. It follows immediately that the existence of mathematical objects can never be a matter of logic alone. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 2) | |
| A reaction: Hm. Could there not be a complete set of models for a theory which all included mathematical objects? (I can't answer that). |
| 23442 | Game Formalism has no semantics, and Term Formalism reduces the semantics [Linnebo] |
| Full Idea: Game Formalism seeks to banish all semantics from mathematics, and Term Formalism seeks to reduce any such notions to purely syntactic ones. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 3.3) | |
| A reaction: This approach was stimulated by the need to justify the existence of the imaginary number i. Just say it is a letter! |
| 20950 | German Idealism says our thinking and nature have the same rational structure [Bowie] |
| Full Idea: German Idealism aims to demonstrate that our thinking relates to a nature which is intelligibly structured in the same way as our thinking is structured. | |
| From: Andrew Bowie (Introduction to German Philosophy [2003], 3 'Limits') | |
| A reaction: Now that's an idealism I might buy into. Frege thought his logic was mapping rational reality. My angle is that we are a product of this 'reality', so we should expect our thinking to be similarly structured. Reason is derived from nature. |
| 20942 | Nazis think race predetermines the self [Bowie] |
| Full Idea: The Nazi idea is that the self is predetermined primarily by its race. | |
| From: Andrew Bowie (Introduction to German Philosophy [2003], Intro) | |
| A reaction: I suspect that I occasionally encounter this view, in very patriotic people. But then you meet people who feeling that their self is mainly determined by support of a football team. Note, though, 'pre-'determined. Hegel makes this idea possible? |
| 20946 | Rhetoric is built into language, so it cannot be stripped from philosophy [Bowie] |
| Full Idea: The attempt to rid philosophy of rhetoric falls prey precisely to that fact that what is involved in rhetoric is inherent in what is built into all natural languages by their genesis in the real historical world. | |
| From: Andrew Bowie (Introduction to German Philosophy [2003], 2 'Hamann') | |
| A reaction: Rhetoric can range from charming to bullying, and it is the latter which is the problem. The underlying issue is dogma versus dialectic. Some analytic philosophers have a good shot at being non-rhetorical. |