The Three Ages of the Interior Life (Les trois âges de la vie intérieure, prélude de celle du Ciel) is the magnum opus of Fr. Réginald Garrigou-Lagrange, a French theologian of the Order of Preachers (Dominican Order). The work is framed according to three stages that mark the common path of Christian perfection, which are described in conformity to the preexisting theology and wisdom of Catholic saints and Church Fathers. His synthesis has become one of the most the dominant present-day interpretations of this patrimony
The Dominican theologian Fr. Reginald Garrigou-Lagrange was a unique blessing ... as a theological advisor to popes from Benedict XV through St. John XXIII. Pope John Paul II, who was taught by Garrigou-Lagrange, alludes the three ages as the horizon for the spiritual life.