You’re right that 50% is the probability of total ignorance, but this is something of a conceptual constant that falls out of the math
Yes, that’s exactly right! It is a conceptual constant that falls out of the math. It’s purely a formality. Integrating this into your conceptual scheme is good for the versatility of your conceptual scheme, but not for much else—until, later, greater versatility proves to be important.
People have a great deal of trouble accepting formalities that do not appear to have concrete practical relevance. This is why it took so long for the numbers 0 and 1 to be accepted as numbers.
I disagree with this bit. It’s only purely a formality when you consider a single hypothesis, but when you consider a hypothesis that is comprised of several parts, each of which uses the prior of total ignorance, then the 0.5 prior probability shows up in the real math (that in turn affects the decisions you make).
If you think that the concept of the universal prior of total ignorance is purely a formality, i.e. something that can never affect the decisions you make, then I’d be very interested in your thoughts behind that.
Yes, that’s exactly right! It is a conceptual constant that falls out of the math. It’s purely a formality. Integrating this into your conceptual scheme is good for the versatility of your conceptual scheme, but not for much else—until, later, greater versatility proves to be important.
People have a great deal of trouble accepting formalities that do not appear to have concrete practical relevance. This is why it took so long for the numbers 0 and 1 to be accepted as numbers.
I disagree with this bit. It’s only purely a formality when you consider a single hypothesis, but when you consider a hypothesis that is comprised of several parts, each of which uses the prior of total ignorance, then the 0.5 prior probability shows up in the real math (that in turn affects the decisions you make).
I describe an example of this here: http://lesswrong.com/r/discussion/lw/73g/take_heed_for_it_is_a_trap/4nl8?context=1#4nl8
If you think that the concept of the universal prior of total ignorance is purely a formality, i.e. something that can never affect the decisions you make, then I’d be very interested in your thoughts behind that.