That statement is too imprecise to capture Jaynes’s view of probability.
Of course; it wasn’t intended to capture the difference between so-called objective Bayesianism vs. subjective Bayesianism. The tension, if it arises at all, arises from any sort of Bayesianism. That the rules prescribed by Jaynes don’t pick out the “true” probability distributions on a certain question is compatible with probability claims like “It will probably rain tomorrow” having a truth-value.
I was pointing out that your original statement characterizing “most people here” as asserting that “probability claims are true …” is antithetical to Jaynes’s approach, which I take as the canonical, if not universal, view on this list.
I don’t see the relation between the two. It seems like you’re pointing out that Jaynes/people here don’t believe there are “objectively correct” probability distributions that rationality compels us to adopt. But this is compatible with there being true probability claims, given one’s own probability distribution—which is all that’s required.
There may be an objectively correct way to throw globs of paint at the wall if I wish to do it in a way that is consistent with certain desired properties given my state of knowledge. That would not make that correct way of throwing globs of paint “true”.
A la Jaynes, there is a correct way to assign degrees of belief based on your state of knowledge if you want your degrees of belief to be consistent with certain constraints, but that doesn’t make any particular probability assignment “true”. Probability assignments don’t have truth value, they assign degrees of belief to propositions that do have truth value. It is a category error, under Jaynes perspective, to assert that a probability assignment is “true”, or purple, or hairy, or smelly.
Sure they do. If you’re a Bayesian, an agent truly asserts that the (or, better, his) probability of a claim is X iff his degree of belief in the claim is X, however you want to cash out “degree of belief”. Of course, there are other questions about the “normatively correct” degrees of belief that anyone in the agent’s position should possess, and maybe those lack determinate truth-value.
If I scratch my nose, that action has no truth value. No color either.
The proposition “I scratched my nose” does have a truth value.
See the distinction. Don’t hand wave it with “it’s all the same”, “that’s just semantics”, etc. You started saying that this is more of a question. I’ve tried to clarify the answer to you.
If I scratch my nose, that action has no truth value. No color either.
The proposition “I scratched my nose” does have a truth value.
Bayesian epistemology maintains that probability is degree of belief. Assertions of probabilities are therefore assertions of degrees of belief, which are psychological claims and therefore obviously have or can have truth-value. Of course, Bayesians can be more nuanced and take some probability claims to be about degrees of belief in the minds of some idealized reasoner; but “the degree of belief of an idealized reasoner would be X given such-and-such” is still truth-evaluable.
See the distinction. Don’t hand wave it with “it’s all the same”, “that’s just semantics”, etc. You started saying that this is more of a question. I’ve tried to clarify the answer to you.
The question was primarily about the role of probability in Pearl’s account of causality, not the basic meaning of probability in Bayesian epistemology.
Of course; it wasn’t intended to capture the difference between so-called objective Bayesianism vs. subjective Bayesianism. The tension, if it arises at all, arises from any sort of Bayesianism. That the rules prescribed by Jaynes don’t pick out the “true” probability distributions on a certain question is compatible with probability claims like “It will probably rain tomorrow” having a truth-value.
I was pointing out that your original statement characterizing “most people here” as asserting that “probability claims are true …” is antithetical to Jaynes’s approach, which I take as the canonical, if not universal, view on this list.
I don’t see the relation between the two. It seems like you’re pointing out that Jaynes/people here don’t believe there are “objectively correct” probability distributions that rationality compels us to adopt. But this is compatible with there being true probability claims, given one’s own probability distribution—which is all that’s required.
There may be an objectively correct way to throw globs of paint at the wall if I wish to do it in a way that is consistent with certain desired properties given my state of knowledge. That would not make that correct way of throwing globs of paint “true”.
A la Jaynes, there is a correct way to assign degrees of belief based on your state of knowledge if you want your degrees of belief to be consistent with certain constraints, but that doesn’t make any particular probability assignment “true”. Probability assignments don’t have truth value, they assign degrees of belief to propositions that do have truth value. It is a category error, under Jaynes perspective, to assert that a probability assignment is “true”, or purple, or hairy, or smelly.
Sure they do. If you’re a Bayesian, an agent truly asserts that the (or, better, his) probability of a claim is X iff his degree of belief in the claim is X, however you want to cash out “degree of belief”. Of course, there are other questions about the “normatively correct” degrees of belief that anyone in the agent’s position should possess, and maybe those lack determinate truth-value.
If I scratch my nose, that action has no truth value. No color either.
The proposition “I scratched my nose” does have a truth value.
See the distinction. Don’t hand wave it with “it’s all the same”, “that’s just semantics”, etc. You started saying that this is more of a question. I’ve tried to clarify the answer to you.
Bayesian epistemology maintains that probability is degree of belief. Assertions of probabilities are therefore assertions of degrees of belief, which are psychological claims and therefore obviously have or can have truth-value. Of course, Bayesians can be more nuanced and take some probability claims to be about degrees of belief in the minds of some idealized reasoner; but “the degree of belief of an idealized reasoner would be X given such-and-such” is still truth-evaluable.
The question was primarily about the role of probability in Pearl’s account of causality, not the basic meaning of probability in Bayesian epistemology.