The Three Ages Of The Interior Life by Réginald Garrigou-Lagrange

The Progress of the Soul from Sensuality to Perfect Charity

A classical Catholic guide to the spiritual life that outlines three successive stages—purgative, illuminative, and unitive—through which the soul is cleansed, enlightened, and ultimately united with God; it emphasizes the indispensable role of grace, prayer, the sacraments, ascetic practice, and virtue in spiritual progress. The work gives practical instruction for spiritual direction, distinguishes authentic mystical experiences from illusion, and stresses humility, obedience, and growth in charity as signs of genuine interior transformation.