“I think metaphysics is the real theory of everything: nothing is off its remit.”
This extreme generality makes it harder to secure feedback about the truth or otherwise of its theories, so there are always many fiercely competing views, some quite extreme, and with no obvious best one even of the less extreme views. Every so often, in fact several times in the history of the subject, this has given rise to a sceptical backlash, with that of logical positivism that you mention being one of the most sustained and radical.
It turned out that the criticisms of the positivists went too far: they were self-undermining. There is a genuine place and need for metaphysics, and if it is suppressed for long, that need makes itself felt. When philosophers avoid it, others spring into the breach: philosophically interested scientists, as well as all kinds of gurus and false prophets.
After several decades in the mid-part of the last century when metaphysics was criticised and largely avoided, it gradually began to revive, at first in the guise of the semantics of natural and artificial languages, what I call Metaphysics-Lite. Since semantics can be done in so many ways, eventually metaphysics was bound to be taken up again for its own sake. It was an interesting development, because a large number of philosophers moved in the same direction independently at the same time. By the 1980s it was making a strong comeback, and since then it has flourished, especially in analytic philosophy. Not so many years ago I was saying we were living in a golden age for metaphysics.
Unfortunately, the rediscovered freedom has again led to some pretty extreme and crazy theories, so another wave of sceptical criticism has followed as surely as day follows night. There has been a return of concern about whether metaphysical disputes are genuine, and a new name for metaphysical reflections on the status of metaphysics: “metametaphysics”. It’s dismaying to find metaphysics through its own excesses being compelled to retrace the steps to legitimation that it so recently took.
I hope the excitement about extreme views dies down and a more level-headed realism returns, but I am not betting on it. Extreme views attract comment both imitative and critical, while metametaphysics tends to undermine the drive for first-order truth. Both divert energies from the serious business of getting metaphysics right.
Thoughts on this thumbnail history and diagnosis of metaphysics are welcome.
The whole interview is here.