Cahn doubts that correct moral standards have been implanted in our minds by god because

People are doubtful in their view of the concept of God. Indeed, there is a wide variance in men's moral standards. Cahn explains that God's existence does not provide any moral precepts. The existence of infections, bad things happening to good people are the mere examples of this concept. Cahn concludes that our morality is not bounded by the existence of God, it has yet to be explored. 

Both the han and the roman empire decline as a result of social unrest during their collapse.