# ... cosmology? KNIGHT & KNAVE

At 09:55 20/07/04 -0400, John Mikes wrote:
```It all depends what do we deem: "POSSIBLE". According to what conditions,
belief, circumstances? If we accept the "here and now"
as "the world", Stathis #1 may be right.
```
```This would mean Stathis first assumption was a first person assumption, but the
whole point of Stathis seems (to me) third person. Also what would be the
meaning of "physical" in a first person assertion.
Perhaps Stathis could comment.```

```Now you are right we should agree on what we deem "POSSIBLE".
With the comp hyp I argued that POSSIBLE = arithmetically consistent, and
then we can go back asking G and G* ....```

```Giving that logic is not so well known apparently
I will soon or later invite you all to Smullyan's knight
knaves Island. It is the gentlest path to G and G* which are the
propositional psychologies from which UDA shows how to
extract the quantum measure in case (comp is true).
And from which I have extract some bits of von neuman's quantum logic
(but I am just beginning opening a vast and heavy doors here).```

```Why not now?  The native of that Island are all either knight or knaves
and knight always tell the truth, and knaves always lie.
You go there.
Problem 1. A native tell you "I am a knight". Is it possible to deduce
the native's type?
Problem 2. You meet someone on the island, and he tells you
"I am a knave". What can you deduce?```

```I would be please to get answers, or critics.
I think it will be useful if only by John Mike remark: we will not progress
if we make not clear the word "possible" in our everything context ...
Logic can help because it is the science of proofS, truthS, and possibilitieS
(note the s).```

`Bruno`

`http://iridia.ulb.ac.be/~marchal/`

```

```