Gerard Philips was a chaplain to the Young Christian Students movement in Belgium as well as a professor of theology at the University of Louvain.
He worked closely with Cardijn in providing training for priests and chaplains in the late 1940s and early 1950s.
Later he became a well known author on lay apostolate before becoming a key figure at Vatican II.
He was the main drafter of Lumen Gentium, the Dogmatic Constitution on the Church.
Réflexions à propos d'un jubilé (1950)