Reddit mentions of Reliable Knowledge: An Exploration of the Grounds for Belief in Science (Canto original series)

https://www.amazon.com/Reliable-Knowledge-Exploration-Grounds-original/dp/0521406706/

https://www.amazon.com/Trust-Science-University-Center-Values/dp/069117900X/

https://www.amazon.com/Golem-Second-Should-Science-Classics/dp/1107604656/

https://www.amazon.com/Science-Salvation-Modern-Myth-Meaning/dp/0415107733/

https://www.amazon.com/Art-Science-Boris-Castel/dp/1551113872/

https://www.amazon.com/Scientific-Literacy-Method-Illini-Books/dp/0252064364/

https://www.amazon.com/Representing-Intervening-Introductory-Philosophy-Natural/dp/0521282462/

As to your question - the next layer would be: what is the difference between a scientific theory and an ad hoc fitting superstition?

Maybe one answer has to do with range. A good theory will fit a wide range of phenomena. "ad hoc" usually refers to a narrow range of phenomena.

Perhaps a fair guess would be that it is fairly safe to extrapolate a theory hmmm 20% beyond the range that it has been tested. If you tested a fit out to 10 miles, you can fairly walk another 2 miles before checking your life insurance policy. If the fit has been tested for 1000 miles, you can feel good for another 200 miles. So if you need to walk say 20 more miles to reach those ripe peaches, better to work with the 1000 mile fit.

From a strictly epistemic point of view, I'm not sure we can. The argument you provided ("it works!") is a common justification, but it relies on the premise that each time we successfully achieve a given end by the application of empirical method, we contribute further to its validation. If I recall correctly, Popper attempted to promote a similar explanation as a complement to his falsification method, which is, as best I can tell, the party line for most champions of the empirical method these days.

When you get into the nuts and bolts of empiricism, though, "it works!" runs afoul of the problem of induction, as made famous by David Hume. Put briefly, there is no logical justification for conclusions drawn solely on the basis of induction. In essence, the fact that the sun rises every day does not logically entail the conclusion that the sun will also rise tomorrow. Likewise, the apparent fact that empirical method has worked consistently to date does not logically entail that it will always work.

Or, from a more strictly empirical perspective, the fact that it seems to work does not mean that it works because it results in genuine knowledge.

I'd recommend checking out John Ziman's Reliable Knowledge. In my opinion, it provides a more epistemically sound approach to empirical method. Ziman argues that the ultimate product of science is not knowledge in and of itself. Rather, it models analogies of the real word, and what we can actually know is the relationships that hold within those analogies.