malreux said:
On the other hand, the main 'interpretation' of scientific theories in most fields is surely some form of structural realism?
There is indeed difficulty in separating a "pure" observation from a "pure" theory, as we need some kind of model of what we are doing to even read a dial. But I think it is still not so hard, as distinctions go, to distinguish between "a spot appeared on a screen, so I'm detecting an event happening at that point in space and time" and "a particle passed through one/both/neither slit along the way." The former very definitely seems like an observation, the latter, an interpretation. The structural realism certainly applies to our devices-- we all imagine the screen is real, the spot is real. But the extrapolation from what we participate in, and develop as part of what physics is, to everything that happens along the way, was always a bit of a leap of faith for structural realism. Indeed, I've argued that somehow, what seems "realistic" vs. "antirealistic", has gotten inverted-- it seems realistic to me to expect that the universe does not have to behave, when unobserved, the same as it does when it is observed (since observation is a form of making the universe fit into a particular way of interacting with it and conceptualizing it in our limited human brains), and antirealistic to be carried away on a leap of faith.
[2] By your lights Darwin's theory of natural selection was not much better than Lamarck's, at least by the standards of his day.
I don't think so. Darwin's approach makes lots of predictions, like if you change the surroundings of a moth to a differently colored environment, you will expect to watch the moth color gradually change over by natural selection. There is no equivalent at all in Lamarck's theory to that kind of change, simply because moths are not observed to change color in their own lifetime.
[3] Here you make the nice distinction do a lot of work: e.g. you seem to use the term 'theorize' to mean 'add to our theoretical ontology' whereas most people - scientist or non-scientist - would prefer the term 'discover'.
The terms ovelap-- we discovered a theory about dinosaurs. It is considered a very good theory, after some initial modifications, because it became able to predict new fossil discoveries that were indeed later found. There is an important distinction, owed to Popper, between just using a theory to "make sense of" what you observe (which is easily used to fool ourselves, a form of "rationalization" of our findings-- just look at how creationists do it), versus actually making "risky predictions" (predictions that we would have no reason to expect if we had no understanding of that theory). It is the latter that makes us trust a theory, though the former is how we use the theory on a day-to-day basis.
Further, theories can differ whilst predicting the same phenomena - the so-called theoretical underdetermination by data.
But they cannot predict
all the same phenomena, or they do not differ. We don't regard Hamiltonian mechanics as a different theory from Newtonian, though they bear little resemblance at first glance, because they make all the same predictions.
If you think theories are essentially about prediction, or that this is what makes them scientific, consider replacing a certain theory with a long sentence that omits all theoretical terms so far as it can recover them with observation statements.
That fails the most important test of all: Occam's Razor. The job of a theory is to predict, the job of a good theory is to unify those predictions into as simple a framework as possible, and the job of an interpretation of a theory is to "make sense" of what the theory is asserting about reality. But the latter two are not unique, and the last one is downright problematic (but we do it anyway, because no one really holds to "shut up and calculate", no one is really satisfied by that).
This is a very weak argument, essentially arguing that 'if you can't simulate it, you don't know it' - but it sounds plausible enough to me...
I believe I understand what you mean, you are saying that the simple theory is more than just a way to get the predictions in a unified way, it is actually the goal itself. It begins to sound rationalistic, like the first step in saying that nature really does follow mathematical rules, and we are just incompletely converging on them. That argument never really washed for me though, it sounds like we are simply taking our converging accuracy and mistaking it for converging on truth. I just don't see any credible argument that leads to that conclusion, it seems like wishful thinking.