His family was one of the most distinguished in the city of Oudenaarde (Audenarde). After a course in the humanities, begun at the College of Soignies and the petit seminaire of Roeselare and completed in 1835 at the college of the Society of Jesus at Aalst, he entered the Society of Jesus on 11 October 1835. After two years in the novitiate, then at Nivelles, and a year at Tronchiennes reviewing and finishing his literary studies, he went to Namur in September 1838 to study philosophy and the natural sciences. De Buck wrote with ease in Flemish, French, and Latin.