I understand what you are trying to say, but I am struggling to see if it is true.
It’s a straightforward corollary of Bayes theorem: if P(A) = 1 (or P(A) = 0), no amount of later updating can change this value. No matter what strong contrary evidence is presented. This is indeed a simple model of a hardcore theist: he has already set P(god(s)) to true, so he is willing to dig himself a hole of unlimited depth to account for the evidence that oppose the existence of a divinity.
As for some example, Russel’s teapot is a good choice: a teapot orbiting a distant sun in other galaxy. Is it falsifiable? With our current and future technology, probably not. Is it logically falsifiable: yes! Even if you assign a very low probability to its existence, an alien species could just transport us there and show us that there’s such a teapot. On the other hand, as I mentioned earlier, if we had put P(teapot) = 0, then we will never accept the teapot existence, even in the face of space travelling aliens that show us that the thing is actually there.
Rationality is about how to process evidence to change one’s prior, it has very little to say about what belief you start with, besides the fact that it must be expressible with classical logic. To complicate the matter, Bayesian evidence works in such a way that if you classify something as evidence, then it means that its absence will lower the probability of the assertion it is supporting.
To have a belief that is both rational and unsupported, you must start with a model that is at one time compatible with background information, whose support is difficult to obtain and is a better fit than competing models, who might even have easier to obtain evidence. A tough challenge!
It’s a straightforward corollary of Bayes theorem: if P(A) = 1 (or P(A) = 0), no amount of later updating can change this value. No matter what strong contrary evidence is presented.
This is indeed a simple model of a hardcore theist: he has already set P(god(s)) to true, so he is willing to dig himself a hole of unlimited depth to account for the evidence that oppose the existence of a divinity.
As for some example, Russel’s teapot is a good choice: a teapot orbiting a distant sun in other galaxy. Is it falsifiable? With our current and future technology, probably not.
Is it logically falsifiable: yes! Even if you assign a very low probability to its existence, an alien species could just transport us there and show us that there’s such a teapot.
On the other hand, as I mentioned earlier, if we had put P(teapot) = 0, then we will never accept the teapot existence, even in the face of space travelling aliens that show us that the thing is actually there.
I see… I have been using unfalsifiability and lack of evidence as a synonym. The title should have read: a rational believe without evidence
Thank You.
That’s a difficult one to achieve.
Rationality is about how to process evidence to change one’s prior, it has very little to say about what belief you start with, besides the fact that it must be expressible with classical logic.
To complicate the matter, Bayesian evidence works in such a way that if you classify something as evidence, then it means that its absence will lower the probability of the assertion it is supporting.
To have a belief that is both rational and unsupported, you must start with a model that is at one time compatible with background information, whose support is difficult to obtain and is a better fit than competing models, who might even have easier to obtain evidence.
A tough challenge!