display all the ideas for this combination of texts
7 ideas
16335 | In Strong Kleene logic a disjunction just needs one disjunct to be true [Halbach] |
Full Idea: In Strong Kleene logic a disjunction of two sentences is true if at least one disjunct is true, even when the other disjunct lacks a truth value. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 18) | |
A reaction: This sounds fine to me. 'Either I'm typing this or Homer had blue eyes' comes out true in any sensible system. |
16334 | In Weak Kleene logic there are 'gaps', neither true nor false if one component lacks a truth value [Halbach] |
Full Idea: In Weak Kleene Logic, with truth-value gaps, a sentence is neither true nor false if one of its components lacks a truth value. A line of the truth table shows a gap if there is a gap anywhere in the line, and the other lines are classical. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 18) | |
A reaction: This will presumably apply even if the connective is 'or', so a disjunction won't be true, even if one disjunct is true, when the other disjunct is unknown. 'Either 2+2=4 or Lot's wife was left-handed' sounds true to me. Odd. |
3326 | Set theory attempts to reduce the 'is' of predication to mathematics [Benardete,JA] |
Full Idea: Set theory offers the promise of a complete mathematization of the 'is' of predication. | |
From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.13) |
3327 | The set of Greeks is included in the set of men, but isn't a member of it [Benardete,JA] |
Full Idea: Set inclusion is sharply distinguished from set membership (as the set of Greeks is found to be included in, but not a member of, the set of men). | |
From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.13) |
16309 | Every attempt at formal rigour uses some set theory [Halbach] |
Full Idea: Almost any subject with any formal rigour employs some set theory. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 4.1) | |
A reaction: This is partly because mathematics is often seen as founded in set theory, and formal rigour tends to be mathematical in character. |
3335 | The standard Z-F Intuition version of set theory has about ten agreed axioms [Benardete,JA, by PG] |
Full Idea: Zermelo proposed seven axioms for set theory, with Fraenkel adding others, to produce the standard Z-F Intuition. | |
From: report of José A. Benardete (Metaphysics: the logical approach [1989], Ch.17) by PG - Db (ideas) |
13282 | Aristotle relativises the notion of wholeness to different measures [Aristotle, by Koslicki] |
Full Idea: Aristotle proposes to relativise unity and plurality, so that a single object can be both one (indivisible) and many (divisible) simultaneously, without contradiction, relative to different measures. Wholeness has degrees, with the strength of the unity. | |
From: report of Aristotle (works [c.330 BCE]) by Kathrin Koslicki - The Structure of Objects 7.2.12 | |
A reaction: [see Koslicki's account of Aristotle for details] As always, the Aristotelian approach looks by far the most promising. Simplistic mechanical accounts of how parts make wholes aren't going to work. We must include the conventional and conceptual bit. |