I think the obvious next step beyond a set of ideas being internally consistent is keeping those ideas consistent with the universe. For better or worse, the universe is our context, and it doesn’t seem to much care for debate on how it works. I may think it would be really great if I could live forever, but reality suggests I can’t, so I shouldn’t grow attached the the idea of immortality.
On the other hand, the universe is full of change, so holding ideas consistent with reality necessitates holding a lot of conditional ideas. It’s good to go outside and get some sun, until the sun becomes a cause of cancer. Being consistent with the universe doesn’t mean siding with the sun and getting cancer; it means recognizing the risk of cancer and not going in the sun so much.
Even a principle as abstract as consistency with the universe already suggests to me some immediate implications for practical decisions. Accepting consistency with the universe as a virtue means avoiding any long-term escapism, e.g. heavy drug use, immersive fiction, or - most extreme - suicide.
Escapism is certainly appealing; the universe can be harsh. For some people, I can imagine it’s so harsh that they just can’t make it work. But because it’s nowhere near that difficult for me, even in my most self-pitying moments, any escape will be temporary. And when it ends, when I go back to facing reality, the escape will prove regrettable, a missed opportunity, a procrastination.
A procrastination from what, I have no idea. I don’t know where the universe is heading, or even if it has a direction. But it’s going to take me along whether I like it or not, so I might as well appreciate the experiences, even the most difficult, as much as I can.
So to review: I’d like my ideas to not contradict each other, nor to contradict reality. I realize I’ve skipped over a big question here: what exactly is reality? I’ll have to come back to that later.