Civil religion is a concept that originated in French political thought and became a major topic for American sociologists since its use by Robert Bellah in the 1960s. It means the implicit religious values of a nation, as expressed through public rituals, symbols (such as the national flag) and ceremonies on sacred days and at sacred places (such as monuments, battlefields or national cemeteries). It stands outside the churches, although church officials and ceremonies are sometimes incorporated into the practice of civil religion.