Combining Texts

All the ideas for '67: Platonic Questions', 'Philosophical Implications of Mathematical logic' and 'Intro to I: Classical Logic'

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4 ideas

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.
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
Logic is highly general truths abstracted from reality [Russell, by Glock]
     Full Idea: In 1911 Russell held that the propositions of logic are supremely general truths about the most pervasive traits of reality, to which we have access by abstraction from non-logical propositions.
     From: report of Bertrand Russell (Philosophical Implications of Mathematical logic [1911]) by Hans-Johann Glock - What is Analytic Philosophy? 2.4
     A reaction: Glock says the rival views were Mill's inductions, psychologism, and Frege's platonism. Wittgenstein converted Russell to a fifth view, that logic is empty tautologies. I remain resolutely attached to Russell's abstraction view.
15. Nature of Minds / A. Nature of Mind / 2. Psuche
When the soul is intelligent and harmonious, it is part of god and derives from god [Plutarch]
     Full Idea: The soul, when it has partaken of intelligence and reason and concord, is not merely a work but also a part of god and has come to be not by his agency but both from him as source and out of his substance.
     From: Plutarch (67: Platonic Questions [c.85], II.1001)
     A reaction: A most intriguing shift of view from earlier concepts of the psuché. How did this come about? This man is a pagan. The history is in the evolution of Platonism. See 'The Middle Platonists' by John Dillon. Davidson is also very impressed by reason.
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
It is good to generalise truths as much as possible [Russell]
     Full Idea: It is a good thing to generalise any truth as much as possible.
     From: Bertrand Russell (Philosophical Implications of Mathematical logic [1911], p.289)
     A reaction: An interesting claim, which seems to have a similar status to Ockham's Razor. Its best justification is pragmatic, and concerns strategies for coping with a big messy world. Russell's defence is in 'as much as possible'.