Simply put, no. No it is not. Not unless the physicist can provide a reason to believe he is correct. Now, in common practice we assume that he can—but only because it is normal for an expert in a given field to actually be able to do this.
That’s what makes the physicist an authority. If something is a reliable source of information “in practice” then it is a reliable source of information. Obviously if the physicist turns out not to know what she is talking about then beliefs based on that authority’s testimony turn out to be wrong.
Here’s where your understanding, by the way, is breaking down: the difference between practical behavior and valid behavior. Bayesian rationality in particular is highly susceptible to this problem, and it’s one of my main objections to the system in principle: that it fails to parse the process of forming beliefs from the process of confirming truth.
The validity of a method is it’s reliability.
No researcher could ever get away with saying, “Dr. Knowsitall states that X is true—not without providing a citation of a paper where Dr. Knowsitall demonstrated that belief was valid.”
The paper where Dr. Knowsitalll demonstrated that belief is simply his testimony regarding what happened in a particular experiment. It is routine for that researcher to not have personally duplicated prior experiments before building on them. The publication of experimental procedures is of course crucial for maintaining high standards of reliability and trustworthiness in the sciences. But ultimately no one can check the work of all scientists and therefore trust is necessary.
Here is an argument from authority for you: This idea of appeals to authority being legitimate isn’t some weird Less Wrong, Bayesian idea. It is standard, rudimentary logic. You don’t know what you’re talking about.
That’s what makes the physicist an authority. If something is a reliable source of information “in practice” then it is a reliable source of information. Obviously if the physicist turns out not to know what she is talking about then beliefs based on that authority’s testimony turn out to be wrong.
The validity of a method is it’s reliability.
The paper where Dr. Knowsitalll demonstrated that belief is simply his testimony regarding what happened in a particular experiment. It is routine for that researcher to not have personally duplicated prior experiments before building on them. The publication of experimental procedures is of course crucial for maintaining high standards of reliability and trustworthiness in the sciences. But ultimately no one can check the work of all scientists and therefore trust is necessary.
Here is an argument from authority for you: This idea of appeals to authority being legitimate isn’t some weird Less Wrong, Bayesian idea. It is standard, rudimentary logic. You don’t know what you’re talking about.