REIFFENSTUEL, Anacleto. – Canonist and theologian of the Order of Friars Minor, born at Tegernsee in Bavaria on 2 July 1641, died at Freising on 5 October 1793. He taught philosophy, theology, and canon law in the internal schools of the Order, attaining the title of emeritus lecturer. From 1683 he held the chair of canon law at the public University of Freising.
He distinguished himself by his profound juridical culture; he consolidated his fame with the well-known *Inus canonicum universum* (Freising 1700–14 and following; vols. IV and V are posthumous, as is the treatise *Regulus iuris*, first published at the end of the Ingolstadt edition of 1733), which earned him the title of prince of canonists of his time and a prominent place among the most celebrated treatise-writers of all ages. A compendium of this work exists for scholastic use (Paris 1853).
R. is also widely known among moralists for his classic *Theologia moralis* (Munich 1692), which, even during his lifetime, enjoyed wide circulation and within a short time ran to more than thirty editions in Germany and abroad. In this field he rendered great service through the systematic treatise method. He professed probabilism, but after his death his treatise was adapted to the probabilism of Fr. Flaviano Ricci da Cimbria by order of the superiors of the Order.