I don't think my position disagrees with you. I make a distinction between theories in theoryspace and parameters in parameter space (given a model we all agree

I don't think my position disagrees with you. I make a distinction between theories in theoryspace and parameters in parameter space (given a model we all agree on). I define theory as essentially a causal model and explanation of some phenomenon, whereas a model may or may not be causal. Much of science (particularly the life sciences) is estimating model parameters, and not actually positing new theories. For example, if you're testing a small molecule drug to see if it lowers blood pressure, you want to know how much it affects blood pressure. This is a parameter estimation problem. We all agree that the molecule will get into the body and interact with other molecules, we just don't know how much these molecular interactions will affect blood pressure. Since Nature publishes a lot of life science stuff, it's no surprise that most of their papers are about parameter estimation given an implicitly agreed upon model. This sort of parameter estimation is important and very different than positing new theories (e.g. quantum mechanics or germ theory). It doesn't make sense to talk about falsifiability of a parameter value. It only makes sense to talk about falsifying an entire causal theory. "All swans are white." is a theory about swan-ness and should be falsified. "What proportion of swans are white?" is a parameter estimation problem and it doesn't make sense to talk about falsification. Theories must be falsifiable and subject to falsification. I don't think this precludes gathering corroborating evidence for a theory and then updating your belief about that theory, but it is very easy to find corroborating evidence for theories so falsification is the most practical means of actually finding truth without fooling yourself. i.e. it is very easy to posit two different theories that make the same predictions in some domain, therefore all evidence in that domain supports both theories. The only practical way to distinguish them is to find another domain where they make different predictions and falsify one or both.