Platonic Idealism/Cartesian Idealism

From: Marchal <>
Date: Thu Jun 1 07:28:30 2000

Brent Meeker wrote:

>Bertrand Russell showed that time as a continuum could be constructed from
>finite perceived intervals. The ordering relation is given by the overlap of
>the intervals. It seems to me that these discussions are sometimes
>confused as
>to whether the argument is going to take a Cartesian direction from something
>we perceive directly -- "there is a thought" -- to the apparent physical
>or instead to assume some Platonic ideal --- the ensemble of all logically
>possible worlds -- and try to show that it makes us and our world at least
>probable. These are both interesting approaches and need not contradict; but
>it gets muddle when one slides from one to the other.

It is the first (cartesian) one from a local 1-person point of view.
But it is the second one (Platonic ideal) from the Sirius 3-person point
view. Not only these are both interesting and not contradictory
but these are both inescapable.
To sum up : 1) what you call platonic corresponds to what I call
"3-person point
of view" (even the sirius one, or the panspectator's one to take
term). 2) what you call cartesian corresponds, I guess, to what I call
the first
person point of view. They correspond here to the "observer-moment".

To hunt the wabbits and other flying pigs, you need (with comp) to
isolate a
(unique) measure on the set of all (relative) computational histories. To
that measure I argue (elsewhere) that you need both point of view.
This is linked to the fact that you cannot solve the problem of the
origin of
(the beliefs in) the physical laws without having at least a minimal
account of
mind or consciousness. (With comp they are deductively related, look in
archive at

Brent Meeker insist:

>As I have remarked before, there are two opposite ideas of 'fundamental'.
>Above is the Platonic fundamental - i.e. the simplest thing, which we ASSUME,
>and from which all else is explained. Just below, is the Cartesian
>'fundamental' - i.e. the thing surest and most obvious to us - our own stream
>of thoughts. Either way is an interesting and legitimate viewpoint - but
>I see
>a lot of exchanges here where one party is Platonic and the other is
>and they make assertions about what is 'fundmental' as though they are
>disagreeing, when they are really speaking different languages.

I agree with you. We *must* mix the views.

But that is why it is usefull to keep clear the 1/3-distinction.
The searched measure
is defined on a set of first-person point of view (the observer-moment)
is itself defined in a platonic 3-person description (like the everything
hypothesis, the all computationnal histories, arithmetical truth, the
of math, etc.).

PS Try to stay on-line.

Received on Thu Jun 01 2000 - 07:28:30 PDT

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