The political and cultural history of Belgium has been characterised by three overlapping zones of tension: the relationship between capital and labour, the religious-philosophical divide and the language dispute between Flanders and francophone Belgium. Of these, the ‘religious-philosophical’ divide, which pitted Catholics against liberal secular free-thinkers, is considered the oldest. It was a feature above all of the nineteenth century, although its influence continued to be felt long after 1900. If the Catholic–secular cleavage ran deep into Belgian society, this was in part because it involved a contest between fundamentally opposed worldviews. Both Catholics and free-thinkers wished to see their respective visions imposed upon the public and private lives of the citizenry; both sought to equate their respective subcultures with the encompassing identity of the nation.

The Catholic model of society was based on religion, understood as the sacred reality of a higher truth. All other religions or convictions were considered aberrations that had no right to exist. It was the church's mission to lead people toward their supernatural destiny. It was thus important that there should be both solidarity and a structural bond between church and society. According to the pastoral logic of the church, a strong ecclesiastical power base was essential, since only Christian social structures would be able to produce good Catholics.