Re: virus: KMO quotes Plato

Jason McVean (
Tue, 29 Oct 96 18:08:13 MST

David McFadzean said:
> At 08:00 PM 23/10/96 MDT, Jason McVean wrote:
> >To say that there is no objective reality means that we have no
> >basis on which to judge the accuracy a desciption.
> I didn't say there is no objective reality, I said that there is no
> objective truth. In contradistinction to a recent post by Tad (and
> messages from me a few months ago) I think they are related but
> saliently different concepts.
> Which is to say, I agree with KMO's replies in this thread.

I may have missed some of this thread so if I'm rehashing, please
forgive me.

Hmmmm... I guess I can't argue with that distinction (between
objective reality (OR) and absolute truth (AT)) because it seems
to be one of semantics. I define AT as OR but I suppose I could
be swayed from that if I was presented with a good reason.
However, it seems to me that that is a useful definition of AT.

Not wanting to belabor the point, let me just make a few comments
that clarify the idea in my mind.

The truth value (TV)--say on a scale from 0 to 1--of a statement can
be defined as how closely the statement resembles the AT/OR.
Keep in mind that I'm talking about statements like "the
brightness of that star is X" and not those such as "my favorite
colour is red". As I've said, I agree that we can't know the AT
perfectly, that doesn't mean we can't measure the TV of a
statement. Here's an example:

Every time I measure the brightness of a star, I get a different
answer and I can never say that one of those measurements was the
"correct" one. However, I can calculate the standard deviation of
the measurements from the mean and use this as an uncertainty. In
other words, I can calculate the likelyhood that my mean
measurement is within a certain range of the true value. So
(1/TV) for a statement can be compared to the uncertainty of a

Notice that I used the phrase "true value" in the second last
sentence. I could have said "value in objective reality" or maybe
"objective value" but these are cumbersome, potentially confusing,
and not any more informative. But I obviously don't want to say
"true value" if everyone is then going to claim that truth
doesn't exist. That's why I'm perhaps stubbornly refusing to let
the subject drop... as I'm sure most people would like :-)

And yes, I agree that the TV of many staements is hard to know
precisely, but that is really the same as saying that the
statement has a larger uncertainty. In fact, one over the
standard deviation is often used as the weight assigned to a
measurement. So extending the comparison, the weight you ascribe
to a claim is equal to it's TV. That's why you'll almost never
hear me say "I'm sure of that" or "I know that this is true". I
almost always use words like "probably" or "unlikely" or "almost


Dept. of Physics and Astronomy University of Calgary

"And it would have worked if it weren't for those meddling kids."