To the extreme positivists who insist that science should stick with the surface data only, not speculative theories, and that science can only describe the world never explain it, here’s another homegrown example to add to your shortcomings.
Standing in the communal shower at the public pool, my pool-friend the anti-Chomskean linguist, put forward his view of the unfortunate fact that the showers always seem to get too hot to bear. I explained that it is likely because the boiler overheats the reservoir of water. If you turn all the showers at once, to draw that hot water reservior out and bring cold water into the boiler reservoir, you’ll notice that the showers will get cooler.
He scoffed. He, instead, goes from shower to shower, using the few seconds of colder water that has been sitting in the pipe, and cobble together a quick shower from among them.
I pointed out to him, that my theory is falsifiable, and I’ve empirically tested it several times. I turn on all the showers; they get cooler. Let the showers stop; the remaining shower gets too hot again. You could even gauge the rough quantity of the reservior in the boiler, if you could gather the water in the showers — all without actually going to look at the boiler.
He insists that my theory is mere speculation and not science.It’s not true, he says.
So I asked him for his theory of why the water is too hot but sometimes gets cooler. His answer: there are areas of scalding hot water, and areas of cooler water. That’s all.
Notice that this is a no-theory theory. It’s akin to “God likes it that way.” In fact, it leads to that belief. Why is the water hot now or cooler now? Because it’s hot now or cooler now. The dormative power. This is not predictive, and prediction is the justification of any theory. Truth can’t be the justification of a theory, because we don’t have absolute access to truth. I mean, it could be that the boiler-deity just does what she likes with the water. No theory can disprove that. But to the extent that my theory is predictive, then who needs the boiler-deity even if she exists? I’ve got a better theory: the boiler-deity theory isn’t predictive even if true, while my theory is predictive even if it isn’t true.
That’s science. Holding that scientists believe their theories are true, is probably the reason people balk at scientism. But scientists themselves don’t believe their theories are true, they hold them because they are predictive or because they are consistent with all the other predictive theories or because they are maximally efficient and informative (elegant). Science is not knowledge so much as an investigation into knowledge contingent on evidence, however that is construed. An investigation is a process, not a body of knowledge. What qualifies as evidence is a bugbear. But that’s as much a problem for the extreme positivist as for a theory-builder.