Quoting a high end philosopher with an incomprehensible
unrelated quote makes your argument unassailable by small minds.
Sorry, a bit of a (bad) joke on my part given your signature, but
also serious. Let me be less cryptic.
Folk Psychology is an idea of Paul Churchland. I took a philosophy
of mind seminar, and it's the idea that resonated with me most.
Basically it says that these mental states we ascribe to people don't
necessarily reflect the actual processes and are just a way humans
understand and interact with the world and other people. When you say
thinking you are using a folk psychology notion that isn't consistent
with other people and probably not internally consistent with your
other beliefs. Folk psychology also implies that introspection is not
as valuable as people imagine for answering these questions.
Of course, when thinking is scientifically defined, it will be
related to the folk psychology notion otherwise they won't use the
term thinking, but it should be rigorous enough to allow scientific
progress.
But to your point, let's assume we could create a set of objects
that can't think (even though we haven't defined what think really
means.) I'm not sure that's much progress. There are a lot of things
in the world, and it's the tricky ones that are really informative to
the definition (just look at how ML works.) While I agree that some
eventual scientific definition will exclude rocks and chocolate,
people will have different opinions on things like snakes, ravens, and
Claude Opus 4.5.
As for Popper, I've read some of his stuff a long time ago for a
philosophy of science course. While interesting and influential, it's
a bit dated. From my perspective, it's precomputer, so it misses
important questions about how science is done. Current philosophy of
science people seem to dismiss it for other reasons.