France, Sept. 23 -- Pope Leo XIV's four-day visit to France from Friday will put one of the country's oldest tensions back in the spotlight - how a nation shaped for centuries by Catholicism reconciles that heritage with one of Europe's strictest models of secularism.

The Pope's programme includes large public gatherings, processions and an open-air Mass in central Paris, all taking place in a country whose constitution defines France as an "indivisible, secular, democratic and social Republic".

This principle is known as laicite - a form of secularism that guarantees freedom of belief, while requiring the state and public institutions to remain neutral towards religion.

Religion is not excluded from public life and people in France re...