----- Original Message -----
From: "Hal Finney" <[EMAIL PROTECTED]>
Sent: 27 May 2005 19:19
Subject: RE: White Rabbit vs. Tegmark
> To summarize, logic is not a property of universes. It is a tool that
> our minds use to understand the world, including possible universes.
> We may fail to think clearly or consistently or logically about what
> can and cannot exist, but that doesn't change the world out there.
> Rather than expressing the AUH as the theory that all "logically possible"
> universes exist, I would just say that all universes exist. And of course
> as we try to understand the nature of such a multiverse, we will attempt
> to be logically consistent in our reasoning. That's where logic comes in.
I basically agree with this (and with Brent's similar comment). In
philosophy we tend to use 'logically possible' to distinguish from
'physically possible', the first usually means 'not violating deductive
logic', the second 'not violating physical laws'. So no 'round squares' in
the case of 'logically possible' - but, as you imply, that should really be
thought of as a feature of descriptions, not universes themselves. (I make
that very point in my paper.)