Pillarisation (a calque from the Dutch: verzuiling [vɛrˈzœylɪŋ] ) is the vertical division of a society into separate groups, or pillars (Dutch: zuilen), organized along religious, socio-economic, and ideological lines. The phenomenon is most closely associated with historical examples in the Netherlands and Belgium.
In a pillarised society, each pillar maintains its own institutions and social organizations. These may include newspapers, broadcasting organisations, political parties, trade unions, farmers' associations, banks, shops, schools, hospitals, universities, scouting groups, and sports clubs. This segregation results in limited social interaction between members of different pillars. In the Netherlands, society was historically divided into four main pillars: Catholic, Protestant, Socialist, and Liberal. The system allowed each community to maintain its own institutions and lifestyle, minimizing conflict among groups. Inter-pillar social relationships, including marriage and friendship, were generally discouraged.