An epistemic sense has to do with individuals' beliefs, right? — Terrapin Station
If I believe that I don't know if A or B is the case, does it follow that I believe that it's possible that either A or B are the case? — Terrapin Station
Yes, if you are using 'possible' in the epistemic sense; — Pierre-Normand
Maybe post when you're not so busy, so that it doesn't take so long to get a simple yes or no answer? — Terrapin Station
Really? You can't wait ten minutes? Should I take an appointment with your personal secretary, next time? I am allowed more than one bathroom breaks in a day? — Pierre-Normand
Don't you ever have time available where one wouldn't have to wait ten minutes for a response in a conversation? — Terrapin Station
Well, the epistemic sense is about what I believe. So if I believe that it's not in fact possible for A or B to have obtained--I believe that it's only possible for one of them to have obtained and the other was always impossible (even before one obtained), then how does my saying "I don't know" imply a belief that both are possible? I rather explcitly believe that one was never possible; I simply don't know which one was possible. — Terrapin Station
Are you simply asking my personal view, outside of the context of what I was talking about? If so, then yes, certainly. Keep in mind that I'm not a determinist — Terrapin Station
Getting to the won't answer a simple question point. Nice. — Terrapin Station
So it's possible that I have a brother.
I don't have a brother.
What does this say about your claim that it's possible that I have a brother? Does it make sense to say that your claim/belief was illusory? I don't think so. — Michael
Well, the epistemic sense is about what I believe. So if I believe that it's not in fact possible for A or B to have obtained--I believe that it's only possible for one of them to have obtained and the other was always impossible (even before one obtained), then how does my saying "I don't know" imply a belief that both are possible? I rather explcitly believe that one was never possible; I simply don't know which one was possible. — Terrapin Station
That looks okay to me, but I can't guarantee I'm not missing something. — Terrapin Station
I already mentioned that epistemic possibilities don't entail other sorts of possibilities — Pierre-Normand
You must be missing something. Let's say that A is "I will pick up the cup" and B is "I will not pick up the cup". So ¬◇A ∧ ¬◇B means "it is not possible that I will pick up the cup and it's not possible that I will not pick up the cup". I don't think you meant this. — Michael
Right--for one I misread the "and" as an "or" — Terrapin Station
But epistemic possibility necessarily has to do with the individual's beliefs re possibility, no? — Terrapin Station
In other words, it's either not possible for A or it's not possible for B to have obtained. — Terrapin Station
¬◇A ∨ ¬◇B. Which, again using De Morgan's theorem, just entails ¬◇(A ∧ B), — Michael
It rather seems to me that applying De Morgan's law to ¬◇A ∨ ¬◇B yields ¬(◇A ∧ ◇B). — Pierre-Normand
If either A or B are impossible, then it's not the case that they're both possible.
I think "they're both possible" is ambiguous here. Do you mean "A is possible and B is possible" or "either A or B is possible"? I'm saying the second, not the first. — Michael
Looks like you had this page open for a while before replying. I edited my post a few minutes ago. — Michael
What epistemic possibility "has to do with" is rational people's consistent sets of beliefs — Pierre-Normand
So ¬◇A ∨ ¬◇B. Which, again using De Morgan's theorem, just entails ¬◇(A ∧ B), but then nobody's arguing that. — Michael
But presumably what you would accept is ◇A ∨ ◇B — Michael
So when you don't want to deal with some particular individual's beliefs, you just claim that that is not a rational person. — Terrapin Station
We were discussing rules of inference that are valid for epistemic logic, — Pierre-Normand
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