In the world of Islam and of Greek/Russian Orthodox Christianity, faith was deliberately and unconsciously integrated with the state - the emperor of the east Romans had a paramount position over the Christian church beginning with Constantine and his first great council - and lasting after the fall of the city in 1453 in Russia, where the Tsars assumed that authority and christened Moscow as the third Rome. Islam had a similar office in the Caliphate - a position in the early centuries of both civil and religious authority, simply because Muslims could not conceive that the two were separate, but rather aspects of the same authority devolving from the one God. This 'ummah' for Muslims, and empire for eastern Christians was Truth with a capital 'T'. It did for a time have its counterpart in the West in the concept of Christendom - but the West was different from the 5th century on.
What happened then, of course, was the collapse of a central imperial authority, and its replacement by a multitude of civil authorities in the persons of tribal kings, and a separate but unified religious ideal inherent in the papacy. Now this is all very simplified, but I think does get to the roots of the difference - from the 5th century onward sacred and secular began slowly, glacially to separate. This is a leap, but what followed was the rise of individualism and intellectualism in the Renaissance - evidenced firstly in art, architecture, poetry and prose - still religious in focus, but aimed at a wider audience and expressing the individuality of the artist as much as the subject matter of God.
Once on this track, the West produced the Enlightenment, science, and overt atheism and overt secularity. It is the Enlightenment which engages my meditation. This cultural movement produced an ummah of individuals who were trained in and practised at the art of looking at oneself and at one's own culture as though it were a foreign place - I would submit that the eastern mentality of Muslim and Greek Christian never did experience this cultural alteration - that the mindset is one of a holistic integration of body and soul - or church and state, or faith and secularity - that the ability to look dispassionately at oneself is not a skill set found outside the West.
OK! That off my chest, and back to marking......