All of us have our personal realities, things that we think make up what is true, whether or not God exists, whether or not owning guns makes us safer, whether or not global warming is real, whether or not there are ghosts.
How do we come to believe in what makes our reality. Never mind that it's because it's what is real that's obvious, because there are a lot of people who would disagree with you who have different realities. So, we come to believe in things mainly because people we trust believe in the same things. If we are given new information we digest that based on how much we trust the person who gave us that information, how much it agrees with our view of the world, and what our personality is like, some of us are more open to new information than others, being skeptical of new things is not a personality fault, it just is the way some of us are.
So the world gives us lots of information, lots, more than we can deal with to be sure. Who has the time to investigate whether or not evolution is real, or whether or not video games are bad for our kids, or whether or not politicians are worth the trust we put in them, we have lives to live, and they require more from us than allow us to look into all these different things.
But what winds up happening is that we are placed in a position of not trusting each other because we aren't sure what that person believes in. And we are put in a position of having to argue, or disagree with those who don't believe the same things we do. And if we find someone who does believe the same things we do it is a revelation, a cause for celebration, here is someone who trusted the same people I do, someone who is the same personality type as me.
All this happens because we encourage an open market of ideas, we throw all kinds of information at people and then let them work out what is true and what isn't, even though they don't have the time or energy to really figure these things out. The problem is that the world, the universe, isn't run on opinions it is run on facts, there is a difineable reality.
So let's suppose that we gave the power to people we feel we can trust to say what reality is. Now there is an impulse to avoid this, look at the middle ages where you could be burned at the stake for believing in something other than what the church did, look at regimes like China or North Korea or Iran where the state determines reality for the purpose of hanging onto power. These are bad things. So we need to assume that allowing whoever is in power to determine reality is a bad thing, it needs to be an independent body.
Some might say that this is what science does. But although science accepts evolution many people do not believe in it, or global warming. Science is also very bad at quantifying some things that many people accept as reality, such as the existence of God. So although science should be a major decider of what is reality, after all by it's very nature it is very good at deciding what is real, it shouldn't be the only player, theologians should be involved, philosophers should, common people should. In any rate government should not be involved.
We must also enter into such a idea accepting that reality changes. even the most conservative religious person has to admit that reality is different today than it was 1500 years ago, before we knew that germs existed, before we knew what electricity was. And so although we seek to find a common reality we must allow people to petition that such a reality can change.
So what do we accomplish by this? That there is a reality which is ready made to be accepted, that people do not have to sift through opinions, data, on their own to figure out what is real. That if they decide that what is given as reality is wrong that they may work to change that perception, but the process becomes one of figuring out what is the truth to the benefit of us all, as opposed to fighting other people over what is considered to be an opinion, and not reality.
To say we cannot do this means either that reality is so subjective that it is impossible to define, or that we simply value having our own ideas over agreeing on what is real, or that we can't figure out what is real because our condition, our psychology and the limits of our perceptions don't allow us to. I don't think any of these things reflect well on us as creatures on this planet.