Mr. Sammi

John, what on this earth dis you intend to imply when you said, "our very means of perception lead us to assume inentionality in things". Are you now saying the fruit on the tree invites us to pick it and taste it?

Sammi Na Boodie ()

beausoleil

<a href="http://www.anthropic-principle.com/preprints/gre/greenberg.html" target="_blank">http://www.anthropic-principle.com/preprints/gre/greenberg.html</a>

SSA = self sampling assumption

John Page

Hi Sammi:

I intended that our faculty of perception leads us to reason in terms of cause and effect and ask questions like who, what, why, where when? Some of these questions assume intentionality of some sentient being, (which may not be the case).

Hope this clarifies.

Cheers, John

BolshyFaker

Don't jump on me if Im wrong on this one, but it seems theres a more obvious flaw in the Doomsday scenario than over complicated discussions of probability.

Couldn't humanity reach a size at which the chances of a catastrophe being large enough to wipe out the species was too small to be worth considering? For instance as soon as a viable population is established on Mars (or elsewhere, but presumably given current rates of development Mars could be colnised in the next thousand years) then it becomes more difficult for the most likely scenaios (weapons of mass destruction, asteroid impact etc) to wipe out both colonies since the Doomsday scenario is confined to Earth.

(On a slight side topic surely one of the events that would have a huge impact on fundementalist religous beleifs would be humanity colonising other planets since it would take such a liberal view of both Revelations or the Koran to make the scenario fit another planet no more fundies, now theres a reason to expand the space program)

Anyway, I think what Im saying is that it would only take a relatively short space of time of human development to make the probability of our destruction "as a species" sufficiently unlikely as to make Doom Later the only realistic scenario (pherhaps by a quantum event causing the laws of physics to change).

I know the arguments premise is to make any estimate of Doom seem more likely but if this is balanced by technological progress tending to make doom less likely then does it matter that much? <img src="confused.gif" border="0">

[ July 04, 2002: Message edited by: BolshyFaker ]</p>

beausoleil

That's kind of what I was getting at above. I agree, obviously.

crocodile deathroll

I think The Canadian Philospher John Leslie was largely behind the urns analogy here are a couple of links:
<a href="http://www.anthropic-principle.com/faq.html" target="_blank">Link 1 ANTHROPIC PRINCIPLE</a>
<a href="http://www.lrb.co.uk/article.php?get=gree04_2113" target="_blank">link 2</a>

(Just a little tounge and cheek) I wonder what it would mean if the examiner was a bit deceitful and was only referring to the 10 counter urn when told you it was one counter and one only, but failed to inform you that there were 100 counters with you name inscribed on them in the 1000 counter urn?

[ July 04, 2002: Message edited by: crocodile deathroll ]</p>

John Page

It could, but how would you know? I think you counter argument fails for the same reason as the Doomsday argument itself, absence of cause and effect.

How about: The Doomsday argument is akin to arguing over the chances of it raining tomorrow before weather forecasting had become reasonably accurate.

I think the Doomsday argument only has a point if it can be shown for the topic in question whether human nature tends to optimism or pessimism.

Cheers, John

Synaesthesia

The Doomsday is a statistical truism, but is epistmically useless. It really is of no value to anyone with a vested interest in betting on the imminent end of the world.

The article by Nick Bostrom, the link to which was provided by Beausoleil, seems to miss this essential point.

"The Doomsday Argument tells us to adjust the probability of imminent Doom in the light of the observation that we are alive at this point in human history."

The main problem with the argument is that it provides us no means by which we can actually adjust our belief. Those who use the doomsday argument when the world does not end will be JUST as correct in using the argument as those who use it five minutes before the earth explodes.

It simply indicates the obvious statement that a random pick out of the pool of all people who will exist, the majority of picks will be a part of the largest population groups. No kidding?

There is an additional problem with the argument. Although not as fundamental of a flaw, it is equally devastating to it. The Doomsday argument distinguishes between only two scenarios, doom soon and doom delayed. This is the point BolshyFaker and beausoleil also make: There is actually a set of three seperate scenarios:

1.Cruise-bang: The human population levels off at some point, stays relatively stable for millions of years and then is wiped out.

1.Fizzle-wimper: The reference to TS Eliot's line "This is the way the world ends, not with a bang but a wimper". The population decreases to a negligable amount which persists for a long period of time. In this case the Doomsday argument would equally demonstrate that we are safe and that humanity has a very long time to go!

3.Boom-bang: The assumed scenario of the doomsday argument: The vast majority of humanity exist shortly before the world ends.


Now there is a subtle plausibility given to the argument by some unstated question begging. IF the world ends soon, we will have a Boom-bang scenario and the argument is valid. However if the world does not end soon (and without this assumption, the argument cannot indicate this) the Boom-bang scenario is not necessarily true and the argument is invalid!


I thinkt he most important aspect of the argument is the point that philosophers seem more taken by it than your man on the street. The implication is that delusion will NOT be wiped out be increasing education and more intelligent people. The effect will be that delusionary memes will evolve to be more appealing to our subtle brains, and the sophistication of our intellect will only disguise our lack of understanding.

Pseudoscience is here to stay.

Yours in self-deception,
Synaesthesia

John Page

Syn:

LOL. The first things that came into my mind after reading the above part of your excellent analysis was "just like platform shoes" and "the emperor's new memes".

Cheers, John

Clutch

Very often philosophers discuss an argument at length not because many or any of them believe it sound, but because they find it goes wrong in interesting ways.

Try reading your quote above with "atheism" or "evolutionary theory" put in for "the argument". What you say here amounts to little more than an unsupported swipe at philosophers and higher education more generally.