Islam and modern European Christianity hold incompatible conceptions of what religion itself encompasses

Evidence

But even in the purely religious sphere, there is an important new element in the situation. Islam is not only a different religion; it also embodies a different conception of what religion means—of what it defines, delimits and requires. For most modern Europeans, religion is primarily concerned with belief and worship; religious freedom means the right to hold, express and teach these beliefs, and to organize and conduct the appropriate worship, all this without suffering discrimination in other walks of life. For traditional Muslims Islam has meant all that and much more. In particular, it has meant the right to live by the holy law of Islam, which is concerned not only with belief and worship, but also with a whole range of civil, criminal and especially personal matters. — Bernard Lewis, From Babel to Dragomans, 707

Categorization

• XREF: This distinction between religion-as-private-belief versus religion-as-total-law echoes the framework in Milgrom on extralegal contracting — communal law enforcement outside state structures. Also connects to how the diamond industry’s extralegal regime parallels Muslim communal autonomy.
• DEFINE: Defines the crucial underlying cultural category mismatch driving the Europe-Islam tension.