Specifically, I've made the argument that if morality is to be anything more than a personal preference, an expression about you like or don't like about the world, it has to have some ontological and metaphysical grounding. It's this grounding that makes moral obligations and duties universal. That is to say, a person cannot opt out if they disagree.
For example, let's say you want to engage in sex trafficking. You see this as a good job opportunity. When I say to you that sex trafficking is evil I'm saying something more than "I don't approve of sex trafficking." I'm doing more than expressing my opinion, which you'd be free to disagree with. To say something is evil is to brook no disagreement. Even if you disagreed, you still must stop. That's the difference between preferences and morality. Morality exists independently of your opinions and creates obligations you must recognize. If you are a sex trafficker you must stop. End of story. And to add a clarification, morality means more than that sex trafficking is illegal. Because even if sex trafficking were legal in some nation or world, it would still be wrong.
My point here is that most of us operate "as if" sex trafficking was evil, but often fail to endorse the metaphysics that would make that moral commitment justifiable and coherent. But there is no way around it, if you want to say that sex trafficking is evil, and most of us do, you're committed to making strong metaphysical claims, like it or not.
In a similar way, last week I shared how we need a similar connection between metaphysics and emotion. The two emotions I described were hope and compassion, and how if we don't have a metaphysics to support these emotions we experience distress or exhaustion. As with morality, we feel like we must have these feelings--compassion, hope--but fail to attend how metaphysics makes these emotions coherent and sustainable. For example, if you think the cosmos is directionless and purposeless, that we're all going to be dead one day and that the universe will eventually succumb to the forces of entropy, why should and how could anyone feel hopeful? Hope and metaphysics are intimately related. And yet, there are a lot of people walking around with Christian emotions who are trying to make those emotion jibe with a materialistic metaphysics. That's not a sustainable situation.
Putting it all together, I'm suggesting that a unified theory of life has to align three things:
