Combining Texts

All the ideas for 'Mahaprajnaparamitashastra', 'Intro to I: Classical Logic' and 'Barcan Formulae'

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3 ideas

4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
Barcan:nothing comes into existence; Converse:nothing goes out; Both:domain is unchanging [Vervloesem]
     Full Idea: Intuitively, the Barcan formula says that nothing comes into existence when moving from a possible world to an alternative world. The converse says that nothing goes out of existence. Together they say the domain of quantification is fixed for all worlds.
     From: Koen Vervloesem (Barcan Formulae [2010])
     A reaction: Stated so clearly, they sound absurd. The sensible idea, I suppose, is that you can refer to all the things from any world, but that doesn't mean they are possible. Shades of Meinong. 'Square circles' are not possible.
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic is bivalent, has excluded middle, and only quantifies over existent objects [Jacquette]
     Full Idea: Classical logic (of Whitehead, Russell, Gödel, Church) is a two-valued system of propositional and predicate logic, in which all propositions are exclusively true or false, and quantification and predication are over existent objects only.
     From: Dale Jacquette (Intro to I: Classical Logic [2002], p.9)
     A reaction: All of these get challenged at some point, though the existence requirement is the one I find dubious.
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna]
     Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom.
     From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88)
     A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate').