OK, so your approach is something like "QM has wave function as a basic description, therefore wave function is real if QM is true"? And if QED requires virtual particles to calculate anything useful, then virtual particles "exist", and are not a mathematical artifact of the perturbation theory?
Even once we have accepted, say, quantum mechanics as true, the instrumentalist says there is a further question about whether to take its claims literally or to treat them as mere calculational tools for making predictions.
If that's what instrumentalism is, then I am most definitely not an instrumentalist. To me "accepting QM as true" is a meaningless statement, while "QM is accurate (at explaining and predicting) and fertile (making lots and lots of interesting, useful and accurate predictions)" is a meaningful one.
If your standards for determining what really exists are so high that not even our best-confirmed scientific theories can meet them, then I suspect you're working with a concept of "reality" that I, as a pragmatist, have no use for (and can't even really understand).
I would agree with that, assuming I had "standards for determining what really exists", which I don't. To me everything imaginable exists to the same degree, just in different contexts, be it stars, photons, baseballs, unicorns, thoughts, ghosts or numbers. Which makes the concept of existence so loose as to be meaningless. So I don't see any use for it. If you say that this (obvious to me) approach does not fit neatly to some existing (heh) ontology, I would be quite surprised,
OK, so your approach is something like "QM has wave function as a basic description, therefore wave function is real if QM is true"? And if QED requires virtual particles to calculate anything useful, then virtual particles "exist", and are not a mathematical artifact of the perturbation theory?
Yeah, I believe virtual particles exist. I also believe in the existence of things like phonons, the electromagnetic field, organisms, beliefs and prices. These are all ontological posits of the best theories of the particular domain. I don't ...
What is something you used to believe, preferably something concrete with direct or implied predictions, that you now know was dead wrong. Was your belief rational given what you knew and could know back then, or was it irrational, and why?
Edit: I feel like some of these are getting a bit glib and political. Please try to explain what false assumptions or biases were underlying your beliefs - be introspective - this is LW after all.