Identity is a modeling choice. There’s no such thing in physics, as far as anyone can tell. All models are wrong, some models are useful. Continuity of identity is very useful for a whole lot of behavioral and social choices, and I’d recommend using it almost always.
As a thought experiment in favor of presentism being conceivable and logically consistent with everything you know, see Boltzmann brain—Wikipedia .
I think that counter-argument is pretty weak. It seems to rely on “exist” being something different than we normally mean, and tries to mix up tenses in a confusing way.
(1) If a proposition is true, then it exists.
Ehn, ok, but for a pretty liberal and useless use of the word “exists”. If presentism is true, then “exists” could easily mean “exists in memory, there may be no reality behind it”.
(2) <Socrates was wise> is true.
Debatable, and not today’s argument, but you’d have to show WHY it’s true, which might include questions of what other currently-nonexistent things can be said to be “was wise”.
(3) <Socrates was wise> exists. (1, 2)
The proposition exists, yes.
(4) If a proposition exists and has constituents, then its constituents exist.
(5) Socrates is a constituent of <Socrates was wise>.
(6) Socrates exists. (3, 4, 5)
Bait and switch. The constituent of <Socrates was wise> is either <Socrates>, the thing that can be part of a proposition, or “Socrates was”, the existence of memory of Socrates.
(7) If Socrates exists, then presentism is false.
Complete non-sequitur. Both the proposition-referent or the memory of Socrates can exist in presentism.
Identity is a modeling choice. There’s no such thing in physics, as far as anyone can tell. All models are wrong, some models are useful. Continuity of identity is very useful for a whole lot of behavioral and social choices, and I’d recommend using it almost always.
As a thought experiment in favor of presentism being conceivable and logically consistent with everything you know, see Boltzmann brain—Wikipedia .
I think that counter-argument is pretty weak. It seems to rely on “exist” being something different than we normally mean, and tries to mix up tenses in a confusing way.
(1) If a proposition is true, then it exists.
Ehn, ok, but for a pretty liberal and useless use of the word “exists”. If presentism is true, then “exists” could easily mean “exists in memory, there may be no reality behind it”.
(2) <Socrates was wise> is true.
Debatable, and not today’s argument, but you’d have to show WHY it’s true, which might include questions of what other currently-nonexistent things can be said to be “was wise”.
(3) <Socrates was wise> exists. (1, 2)
The proposition exists, yes.
(4) If a proposition exists and has constituents, then its constituents exist.
(5) Socrates is a constituent of <Socrates was wise>.
(6) Socrates exists. (3, 4, 5)
Bait and switch. The constituent of <Socrates was wise> is either <Socrates>, the thing that can be part of a proposition, or “Socrates was”, the existence of memory of Socrates.
(7) If Socrates exists, then presentism is false.
Complete non-sequitur. Both the proposition-referent or the memory of Socrates can exist in presentism.
(8) Presentism is false. (6, 7)
Nope.