CB,

- So far, I still disagree -- in the end.

- I agree that P(WEBR) + P(~WEBR) = 1.00

- But so far, it still seems to me that the fact of my current existence requires that L(me|WEBR) + L(me|~WEBR) =1.00 also.

- We have two possible hypotheses for "explaining" my current existence: WEBR and ~WEBR. I accept that "explain" isn't quite the right word to use -- but so far, I haven't been able to find the right word (or phrase)...

1) Theoretically, we have an excluded middle here -- which means that between WEBR and ~WEBR, we've covered all the possible bases ("explanations") for the fact that I currently exist -- and,

2) Since I do exist, and since my current existence is part of our background knowledge, I can logically conclude that L(me|WEBR) and L(me|~WEBR) must also add up to 1.00.

- #2 seems to be our hangup. Can you elaborate on why you disagree with me here?.

Let's take a simple counterexample to show why the likelihoods don't have to add to 1.

Imagine you are walking behind someone, and can't make out their gender very confidently. You have observed, however, that they are wearing pants. Let's assume the following probabilities:

50% of people are male, and 50% female; that is, P(Male) = 0.50

A large percentage, say 99%, of men wear pants; that is, L(Pants|Male) = 0.99

But quite a good number of women do too, say 55%; that is, L(Pants|Female) = 0.55

Now answer the following questions:

1. What is the posterior probability that the person is male?

2. Do the two likelihoods add to 1?

3. If not, is there any problem with that? Do the proportion of women who wear pants and the proportion of men who wear pants really have to sum to 1?

If that still doesn't make sense to you, I want you to forget about your immortality argument for a while and go do some actual reading to get a grasp of Bayes theorem. At the moment we are not being held up by a disagreement, but just by you not grasping the framework of Bayes theorem. Please have the humility to accept that.

Once you've done that, if you really want to apply Bayes theorem to your problem, you need to forget about this approach of trying to calculate L(me|~WEBR) from the other probability terms and instead try to find some other way of estimating this probability:

**In a world ***with* immortality or reincarnation, what would be the probability of your current existence?
Note: Even without a good grasp of Bayes theorem, it should be intuitively obvious to you that this should not be a very large probability! By your current assumption, L(me|~WEBR) is close to 1, but that's obviously not the case - for you to exist, even in a world with reincarnation or immortality, all kinds of unlikely things had to go "right".

Sorry to be harsh, but I'm not going to engage further in this discussion unless you show some actual effort at trying to grasp Bayes theorem - I have work to do.