Right, here we go again.
Ayup. Should we limit this conversation to a total length of about seven posts?
You know about solipcism, don't you? Most if not all beliefs that we hold are 'theoretical fantasies'.
From what I've come to understand in the general sense solipcism is understanding that we make a number of assumption to make sense of our observations. Despite having insuficient information to make an incontestable conclusion, we do so anyway. I suppose it can be seen as a kind of belief rooted deep in our instincts.
However to say we make a few assumption in the process of observation is the same as everything we can possibly know is a belief seems a bit of a stretch.
Name a certain belief, then - we start out with no knowledge at all, so that stretch isn't all that big.
Pretty much - it's like the mathematically correct expression of "We need control experiments".
Erm no? It's because no measurement can possibly be perfect. At least that's how I recall it.
I'm just saying that they're similar. "No measurement is perfect" is pretty much identical to "Every experimental result has a chance of being false", if you accept a slightly wobbly definition of 'experimental result'. Even if you don't, we can apply the same idea to both - "We need more measurements to average out the errors and get a more accurate result" and "We need control experiments because each individual experiment has a chance of going wrong".
It's only boring if you don't take it as an invitation to embrace introspection, surrealism, and existential awe. Or, if you're feeling morbid and depressive and such, existential dread - same thing, only one has rainbows and trees and things. You just have to take the day-to-day as an internally consistent fragment of its own, and you're set to be as pants-on-head twisted in your take on the realness of things as you'd like!
Of course, that might also be the road to schizophrenia, but philosophers have gotten to be so safe these days, with their cappuccinos and their college degrees...
Edit: More seriously, knowing that you don't know something, and being able to produce internally consistant Gedanken, is pretty essential to producing new thought and finding ways to break past academic dogma. Yes, there is scientific consensus for certain things. Those things are probably true, whatever that means. Yes, it can be useful to follow that consensus to focus your attention into new areas. But when that well dries up, and there's nowhere else to go but fantasy, your obligation is to fantasize. The idea that we're close to understanding the way the world works is attractive, but it's as much of a dead end as the idea that we can't understand it at all. The key difference is that the latter provides new direction and movement, rather than just butterfly collections.
I meant that solipcism
as a philosophical idea is pretty boring - it doesn't lead to many new insights.
As a concept it's very interesting, but only when applied in moderation - the examples you named are perfect to demonstrate this.
(Also, Gedanken <=> thoughts. Yeas, I know, Everything Sounds More Philosophical in German
The Gestalt of the Nietzschean Übermensch is paramount to the concept of the Ding an Sich in the Weltanschauung of the Nihilist...)