It seems obvious that fundamentalism and too much certainty, in religion, causes great social harm.
On the other hand, it does seem like some metaphysical ideas are needed for a more just society. A vague concept, like Karma, seems to provide more motivation for doing good. Without something like Karma, we are just relying on the feedback from a purely physical world for motivation. Just the payment, or "payback" from the material world isn't enough.
When I talk about Karma, I'm thinking about more universal concepts of morality that invoke metaphysical ideas, not necessarily just Karma itself. I'm mentioning Karma as just a metaphysical feedback system that's somewhat easy to understand.
Without some kind of metaphysical like concepts, the other feedback loops, that come from society and even nature, don't seem to be sufficient. We have the economy which doesn't always reward what is usually thought of as virtue. Often the economy rewards the opposite of virtue.
Another feedback loop is the idea of "what goes around, comes around." Being nice to others usually means they are nicer to you. Basically what we often call "The Golden Rule."
Another virtuous feedback loop is our own health. Healthy living usually enhances health, but that alone doesn't seem to be a powerful enough feedback loop. Not powerful enough, in most people, to overcome the allure of junk food or sedentary lifestyles.
Another non metaphysical feedback loop is the good feeling we get if we know we have helped another person. As for that good feeling, there is some recent science that leans toward explaining it in terms of mirror neurons.
Yes, there are said to be special neurons that bring us empathy. They tend to react to feelings we see in other people. Mirror neurons may have evolved to enhance our survival as they help us function as a social species.
Still, even with our mirror neurons and all the other material feedback loops such as economics, it seems like all of this isn't enough.
I'd think we need yet another "bank account" like concept. A concept such as Karma or other metaphysical ideas to push us over the top toward a more virtuous society.
Karma, or something like the Golden Rule, can provide payback in a secret way. It doesn't even have to wait till an afterlife, it can pay us back in this life. Clean up some litter and good fortune may come your way. It's kind of a loose promise.
In our material society, we have invented various versions of Karma that are more defined. For instance credit scores. There are various theoretical "bank accounts," we create, to try and incentivize useful behavior. Prison can do that as a disincentive for bad behavior.
In China, I hear they are developing a very elaborate system of crediting social good. Beyond just one's financial credit score, everything is watched. Help someone across the street or clean up the park and one gets brownie points. Buck the established system and one gets demerits.
China may be turning into the ultimate "surveillance state."
Personally, I would prefer a less artificial surveillance state, like a vague concept of Karma. If the universe is watching us, it's probably a bit less rigid than the feeling that the government is watching.
It isn't even known, for sure, that the universe is watching, so that may be what gives the concept of Karma more wiggle room.
As for mirror neurons, it reminds me of hearing about "field effect transistors" during my childhood. I often thought of neurons as the "transistors" of our brains.
Back during high school, I got a fancy radio that had a few "field effect" transistors among it's many transistors. That was something quite special, but I never quite figured out what made them so special. My thought, back then, was that field effect transistors helped with sensitivity to faint radio signals.
Might be related. Our empathy and sensitivity; the result of mirror neurons?
It does, though, seem like just these material things don't quite give us enough push toward a more virtuous society. Metephysical concepts; especially from liberal, open minded religions, seem to be important motivations for a virtuous society.