Metaphysics, i.e the study of “things” outside of physical reality, is incredibly dangerous for politics. But first, why do we use metaphysics?
For some reason or other, human beings need to use abstracts to express themselves. We cannot always refer our ideas to concrete things. There is a whole field of philosophy that studies this and related issues but I have no time for it. I am concerned with reality and politics, so philosophical disagreements over why we need abstracts are of no interest. But basically we need concepts that are not physically real in order to communicate. So, metaphysics is necessary.
The problem is that, throughout the history of western philosophy, philosophers have turned such metaphysical concepts into systems of metaphysical concepts. They have then insisted that we human beings can find the “real” truth of existence in their specific system of metaphysics rather than in physical reality. The ancient Greeks certainly had a good excuse for doing this: they wanted to understand the world and they did not have other tools beyond “reason” to do so. But today we do not have this excuse, since it has been a few hundred years since the development of the scientific method (which is wholly contrary to systematized metaphysics).
Because we humans need and like traditions, we have stuck to systematized metaphysics despite its lack of success in understanding or explaining reality. The most obvious form of systematized metaphysics is, of course, religion. But a far less obvious form is that which most political ideologies take: some form of secular religion.
The biggest problem with systematized metaphysics for political life is that metaphysical ideologies focus on absolute concepts (freedom, justice, equality, affluence, utopia, the garden of Eden etc) rather than actual political issues (preserving individual rights, fair trials, unemployment insurance, etc). Most if not all of these metaphysical ideologies (regardless of their position in the political spectrum as there are left-wing, right-wing and centrist metaphysical ideologies) claim that there is a perfect end-state which we can achieve as a society if we would all just jump on the bandwagon. Since this is not an actual possibility, the idea is extremely dangerous. It is perhaps the biggest ideational force in the cycle of revolutions.
[Seemingly unrelated Addendum:]
All people generally think alike and don’t think alike at the same time. We have some things in common and other things which aren’t in common. But the claim there is a class, a coherent, self-contained ruling elite, that is distinctly different from the average joe, has no basis in fact; its basis is in the desire of some to believe that they are being directed by powers greater than themselves (which is, incidentally, a form of metaphysics). How did we get back on this again?
C. Wright Mills, for example, has been totally utterly refuted. There are other examples which I can’t think of right now.
I think we are talking about two very different things. I’m a little confused.