On Mon, Jan 27, 2020 at 11:30:56PM -0800, Elliot Temple wrote:
> What are some examples people might give [of judging inconclusive arguments and assigning them appropriate weights, choosing both whether it’s positive or negative as well as the size] and what’s wrong with those?
People usually don't give numeric ranges for argument weights, but they may talk about the amount of weight in words, e.g. using the kind of scale Peikoff came up with (I think they were words such as "likely", "probable", "unlikely", etc.). One problem with this is that there's no way to combine those fuzzy weights to get a meaningful total.
People talk about the *sign* of an argument's weight in terms of whether the argument supports or undermines the idea in question. For example, the idea that the sun has risen every day for the last million years (or whatever) might be said to support the idea that the sun will rise tomorrow. One problem with this is that no one has ever explained what it means for one idea to support another idea.
Someone might try to define "support" more precisely by saying that idea Y supports idea X just when P(X|Y) > P(X) (that is, when knowing that Y is the case makes X more likely than X would be if you didn't know whether or not Y was the case). However, this kind of probabilistic justification suffers from a regress problem, as explained in http://curi.us/1594-regress-problems