# Question Concerning Probability Systems

1. Aug 22, 2013

### EricJRose83

Does probability necessitate an underlying deterministic foundation in order to offer a degree of prediction? Thank you in advance!

2. Aug 22, 2013

### Stephen Tashi

I see no way to interpret your words as a specific mathematical question. Can you give an example of a situation where your question has a definite yes-or-no answer?

The forum rules are rather sensitive to people trying to discuss philosophy. I think this comes from a revulsion to such threads popping up in the physics sessions on quantum mechanics, but such threads also tend to get closed in the math sections.

3. Aug 22, 2013

### EricJRose83

Okay, is a degree of predictive probability possible if the variables are not computable?

4. Aug 22, 2013

### Stephen Tashi

You call that a specific question? What is "predictive probability"? For that matter, what is "non-predictive probability"? What's the definition of these "degrees" that you intend to measure it with?

5. Aug 22, 2013

### EricJRose83

Uh, it's kind of self-evident I would think. Predictive probability is a probability system that offers a degree of prediction. A non-predictive probability system wouldn't offer any prediction and there for by definition wouldn't be a probability system. By degree of prediction, I mean something like 1 in 20 chance of a certain outcome being possible, so on and so forth.

I'm simply asking if a probability system necessitates an underlying deterministic system for it to function properly. If not, then what causes one event to be more probable than another?

I think the answer is a resounding yes of course. Seems like a no brainer to me. However, I've met more people than I can count who either fail to understand this very simple concept or simply disagree without offering up an explanation as to why, but instead say, "I don't understand why a probability system would necessitate an underlying deterministic system".

6. Aug 23, 2013

### economicsnerd

Problem solved then?

7. Aug 23, 2013

### HallsofIvy

Staff Emeritus
I think it is more likely that you are the one who fails "to understand this very simple concept". I can certainly postulate a "probability system" which has 3 possible outcomes, A, B, and C, where the probability of outcome A is 1/2, the probability of putcome B is 1/4, and the provability of outcome C is 1/4. What is the "underlying deterministic system" there?

8. Aug 23, 2013

### mathman

Is this a mathematics question or a physics question? "Underlying deterministic" is a physics concept. Mathematical probability starts with Kolmogoroff axioms.