Seems I keep coming back to comparisons with Rome. Roman's virtue/value system was much like ours and they decayed from within as they lost their virtues.

pietas (in the sense of an unswerving sense of duty, devotion, and loyalty to one's family, friends, country, and gods),

gravitas (taking one’s responsibilities seriously and earnestly),

diligence, energy, and industriousness,

steadfastness and patience,

dignity, austerity, and elegance in manner and dress,

restraint and self-discipline (emotional control),

syncretism, open-mindedness, and tolerance.