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Though not a proof of the existence of God as worked on by Godel, but Al Platinga is known for his work for the logical discussion of the rationality or religio

Though not a proof of the existence of God as worked on by Godel, but Al Platinga is known for his work for the logical discussion of the rationality or religious belief Somewhat related excerpt: https://www.princeton.edu/~hhalvors/restricted/plantinga-ReasonandBelief.pdf https://www.princeton.edu/~hhalvors/restricted/plantinga-Rea...

cousin_it 9y ago
Plantinga is known for his proof of God's existence, and in fact a proof of any sentence you like, using the modal logic operators of possibility and necessity: "possibly necessarily pigs fly, therefore pigs fly". (Where "possibly" is shorthand for "in some possible world", and "necessarily" is shorthand for "in all possible worlds".) It's a valid proof if you buy the assumption, but the assumption is dubious at best.
- dvt 9y ago
  Of course it's valid! A world-renowned philosopher like Plantinga wouldn't publish a proof that's not valid. That's like saying Dijkstra's code compiles :) The main problem with ontological arguments (and why, even as a Christian, I don't like them) is because they seem to embed the conclusion in their first premise. E.g.: the possibility of a maximally great being seems to definitionally imply its necessity. Why? Because such a being B must have some properties P = { ? ? ? ... }. We may not be sure what's inside P, but we know, with absolute certainty, that existence is in there. Kant would disagree. He thinks that existence is not a property. This is a rare case when I think he's right.
  - throwaway729 9y ago
    > The main problem with ontological arguments (and why, even as a Christian, I don't like them) is because they seem to embed the conclusion in their first premise But that is also true of the informal rhetorical arguments that are more common in (christian) apologetics. The gift of formal proofs is that they make explicit and unavoidable this embedding of conclusion in premise, which is fundamental to all (epistemologically rational) apologetics
    - dvt 9y ago
      > this embedding of conclusion in premise [...] is fundamental to all (epistemologically rational) apologetics It might be true of all ontological arguments, but certainly not all apologetic arguments.
  - naasking 9y ago
    > E.g.: the possibility of a maximally great being seems to definitionally imply its necessity. One of my favourite tongue-in-cheeek replies I read to these ontological arguments: Ah, but surely there is no greater being than one who could create the universe despite not existing!
- nthcolumn 9y ago
  What is it he has proven the existence of? Can he describe it? Can anyone... please?
  - akud 9y ago
    A maximally great being. As a sibling comment noted, the problem with this argument is that it presupposes the conclusion.
    - deleted 9y ago
      [deleted]

cousin_it 9y ago

Plantinga is known for his proof of God's existence, and in fact a proof of any sentence you like, using the modal logic operators of possibility and necessity: "possibly necessarily pigs fly, therefore pigs fly". (Where "possibly" is shorthand for "in some possible world", and "necessarily" is shorthand for "in all possible worlds".) It's a valid proof if you buy the assumption, but the assumption is dubious at best.

dvt 9y ago
Of course it's valid! A world-renowned philosopher like Plantinga wouldn't publish a proof that's not valid. That's like saying Dijkstra's code compiles :) The main problem with ontological arguments (and why, even as a Christian, I don't like them) is because they seem to embed the conclusion in their first premise. E.g.: the possibility of a maximally great being seems to definitionally imply its necessity. Why? Because such a being B must have some properties P = { ? ? ? ... }. We may not be sure what's inside P, but we know, with absolute certainty, that existence is in there. Kant would disagree. He thinks that existence is not a property. This is a rare case when I think he's right.
- throwaway729 9y ago
  > The main problem with ontological arguments (and why, even as a Christian, I don't like them) is because they seem to embed the conclusion in their first premise But that is also true of the informal rhetorical arguments that are more common in (christian) apologetics. The gift of formal proofs is that they make explicit and unavoidable this embedding of conclusion in premise, which is fundamental to all (epistemologically rational) apologetics
  - dvt 9y ago
    > this embedding of conclusion in premise [...] is fundamental to all (epistemologically rational) apologetics It might be true of all ontological arguments, but certainly not all apologetic arguments.
- naasking 9y ago
  > E.g.: the possibility of a maximally great being seems to definitionally imply its necessity. One of my favourite tongue-in-cheeek replies I read to these ontological arguments: Ah, but surely there is no greater being than one who could create the universe despite not existing!
nthcolumn 9y ago
What is it he has proven the existence of? Can he describe it? Can anyone... please?
- akud 9y ago
  A maximally great being. As a sibling comment noted, the problem with this argument is that it presupposes the conclusion.
  - deleted 9y ago
    [deleted]