[2][3] Along with a strong family tradition of activism, Lucas' social involvement was influenced by Algeria's period of decolonisation and the subsequent challenges to women's rights posed by religious fundamentalists.

She left a university position in human rights research and teaching in the 1980s to help establish the group Women Living Under Muslim Laws (in 1984) and become its first international coordinator.

The organization advocates against allowing separate legal frameworks for people or specific faith communities, such as courts using Sharia law, arguing those regimes are often detrimental to women's rights.

The group also collects and distributes information on the situation of secularists and atheists in countries where Muslims make up a large part of the population.

The debates around immigration in European countries adds a complex dimension to that debate, for Lucas: "Unfortunately, the European Left and Far-Left, that should be our natural allies, have not yet understood that they should not throw themselves in the arms of Muslim fundamentalists in order to counter the traditional extreme right parties…"[3][4][6] She also works to uncover the history of atheism and feminism in countries where Islam has major influence.