It might help to read the linked essay in my previous comment. When one assigns probability 0 or 1 to something, one cannot update based on evidence. That is, if one really believes that, there should be no amount of evidence that will convince you. That’s problematic if one is trying to be a rationalist. And if there is some amount of evidence that can convince you then you don’t really assign probability 0 or 1 to the claim.
One either GOES to the restroom or one DOESN’T go to the restroom. It’s not a 1% possibility thing. Something is or it isn’t. Not a good idea? Based on the fact that once in the courtroom it’s nothing but a big pokergame. But there is 0 evidence.
Probabilities are measures of how certain one is about something. Thus, for example if one is going to estimate how likely a coin is to come heads one will say .5. This doesn’t change the fact that the coin either will come up heads or come up tails. But I don’t know which one it will be. Similarly, if something in the past may or may not have occurred, then you can assign numeric estimates to how likely it is to have occurred.
Why? What negative result follows when you assign probability zero to something? I haven’t consciously experienced any so far.
It might help to read the linked essay in my previous comment. When one assigns probability 0 or 1 to something, one cannot update based on evidence. That is, if one really believes that, there should be no amount of evidence that will convince you. That’s problematic if one is trying to be a rationalist. And if there is some amount of evidence that can convince you then you don’t really assign probability 0 or 1 to the claim.
One either GOES to the restroom or one DOESN’T go to the restroom. It’s not a 1% possibility thing. Something is or it isn’t. Not a good idea? Based on the fact that once in the courtroom it’s nothing but a big pokergame. But there is 0 evidence.
Probabilities are measures of how certain one is about something. Thus, for example if one is going to estimate how likely a coin is to come heads one will say .5. This doesn’t change the fact that the coin either will come up heads or come up tails. But I don’t know which one it will be. Similarly, if something in the past may or may not have occurred, then you can assign numeric estimates to how likely it is to have occurred.