3 ideas
| 15927 | Definition just needs negation, known variables, conjunction, disjunction, substitution and quantification [Weyl, by Lavine] |
| Full Idea: For mathematics, Weyl arrived (by 1917) at a satisfactory list of definition principles: negation, identification of variables, conjunction, disjunction, substitution of constants, and existential quantification over the domain. | |
| From: report of Hermann Weyl (works [1917]) by Shaughan Lavine - Understanding the Infinite V.3 | |
| A reaction: Lavine summarises this as 'first-order logic with parameters'. |
| 15034 | Are genera and species real or conceptual? bodies or incorporeal? in sensibles or separate from them? [Porphyry] |
| Full Idea: I shall beg off talking of a) whether genera and species are real or situated in bare thoughts alone, b) whether as real they are bodies or incorporeals, and c) whether they are separated or in sensibles and have their reality in connection with them. | |
| From: Porphyry (Isagoge ('Introduction') [c.295], (2)) | |
| A reaction: This passage, picking up on Aristotle, seems to be the original source that grew into the medievel debate about universals. It seems to rather neatly lay out the agenda for the universals debate which is still with us. |
| 15788 | Syntax and semantics are indeterminate, and modern 'semantics' is a bogus subject [Quine, by Lycan] |
| Full Idea: Quine has argued tirelessly that syntax and 'semantics' are indeterminate, and linguistic semantics of the sort that is currently in favor is a pseudoscience and a pipe dream. | |
| From: report of Willard Quine (Methodological Reflections on Current Linguistic Theory [1972]) by William Lycan - The Trouble with Possible Worlds 02 | |
| A reaction: I think the defence of such things is that they may not integrate into science very well (or even integrate at all), but semantics is intended to integrate into philosophy, and is motivated by philosophical concerns. Quine may be right! |