I think about Rome's collapse a lot, the economics of it, the spirituality of it, and the tragedy of the eastern Orthodox church usurping the church and their twisting God's love into a cover for them to murder anything deemed heretical. 

As for Daoism, I've been there, been in their temples in China, and read the Dao de Ching several times. If you want an incredibly sublime spiritual experience, read that and the Gospel of John at the same time.