Sure. If we are not able to calculate probabilities for a suggested possibility...then that suggestion is not verified as possible. Its just a made up suggestion.
i.e. Brain in a Vat. — Nickolasgaspar

-"First comes possibility, only then probability. "
-Correct. — Nickolasgaspar

Kindly expand and elaborate. As far as I can tell, probability is the mathematics of possibiliity - it's basically a numerical perspective on possibility. In short, you've put the cart before the horse.

-"As far as I can tell, probability is the mathematics of possibiliity"
-Correct.

-" it's basically a numerical perspective on possibility."
-its a numerical perspective of what is verified as possible.

-"In short, you've put the cart before the horse. "
-No I don't. My sole point was that not all ideas can be treated as "possible".
i.e. The idea "Can the universe sustain life" can be accepted as possible because we already have an example of this possibility and our ability to calculate the conditions and produce probabilities is an indication for that.
That is not true for the "brain in the vat" idea since we have nothing to "explore".
So the process of exploring(identifying, comparing etc) possible scenarios is not just a competition of suggesting stories.

That is not true for the "brain in the vat" idea since we have nothing to "explore". — Nickolasgaspar

What do you mean? The brain in a vat scenario is possible, no? It is an instance of exploring what I refer to as the possibility space (self-explanatory term).

My sole point was that not all ideas can be treated as "possible" — Nickolasgaspar

Of course! I'm not at all saying that, given a set of facts, some possibilities are immediately ruled out.

its a numerical perspective of what is verified as possible. — Nickolasgaspar

And?

Let me clarify my position:

Possible: In the simplest, classical-logic, sense, if x is possible then x doesn't lead to a contradiction.

E.g. if I flip a coin, it's possible to get a head or a tail. Heads and tails are possibilities.

Probable: Mathematically, take what's possible, say x, and find a number that expresses the likelihood of x.

E.g. the probability of getting a heads = $\frac{1}{2}$