Theologian; b. Brecht near Antwerp, Oct. 1, 1554;d. Louvain, Jan. 15, 1623. His family name was Leys. The early loss of his parents produced in him a sobriety and profound introversion that were to last throughout his life and to give impetus to his proclivity toward prayer and serious study. Destined by his uncle for a career in business, Leonard instead won a scholarship at the University of Louvain at the age of 13. There he took courses in arts and philosophy, preparatory to becoming a Jesuit. He distinguished himself by winning the first place in his class. In June of 1572 he was assigned to teach philosophy at the College of Douai. At the same time he began to study theology on his own initiative. He was ordained in 1580 and made prefect of studies at Douai the following year. Later, he was given a sabbatical in Liège and then sent to Rome, where he continued his theological studies under Bellarmine and Suárez. Returning to Belgium in 1584, he taught theology at the University of Louvain. There he shocked some of the older professors by substituting in his classes the Summa of St. Thomas for the customary Liber Sententiarum of Peter Lombard.
From 1564 one of the professors at the university, Michael du Bay (Baius), had been teaching a doctrine suspected by some as being tainted with heresy (see baius and baianism). When some of Lessius' lectures had a tone quite antithetic to the ideas of their master, Baius's followers presented a garbled version of the young Jesuit's theses to the university authorities for scrutiny. Lessius was accused of reviving semi-pelagianism. At the instigation of P. Tolet, the university issued a condemnation of 31 of the supposed propositions of Lessius. In 1586 Lessius published his Theses theologicae, in which he defended the doctrine he was really teaching. A bitter quarrel between the Baianists and Jesuits ensued; Lessius maintained such composure that even his opponents were constrained to express their admiration for him. Eventually, at the request of Sixtus V (d. 1590), the doctrine of Lessius was examined by a commission of theologians and found to be in accord with Catholic dogma.
During his lifetime as a teacher, Lessius published a great number of works, many of which went through several editions even in various languages. Most famous of all was his treatise De justitia et jure (Louvain 1605). The book deals in great detail with the morality of contracts, buying and selling, fair prices, wages, market manipulations, problems of exchange, exploitation of newly discovered lands and their resources, etc. Outstanding in this work was the then novel opinion that taking of interest on loans of money is not in itself sinful. The division of Christianity through the multiplication of sects did not escape his notice or pen; on this question he wrote Quae fides et religio sit capessenda (Antwerp 1609). He also compiled a theological treatise De providentia numinis et animi immortalitate (Antwerp 1613). Lessius' masterful defense of papal authority is not extant today because his superiors, fearful of confiscation and reprisals by the king of France, restricted the circulation of this work.
His defense of molinism in his famous work on efficacious grace, De gratia efficaci (Antwerp 1610), caused quite a controversy among the Jesuits (see grace, efficacious). At first the book was approved by the Jesuit general's office, but later Aquaviva, the Jesuit general, censured it because it failed to distinguish clearly enough the difference between sufficient and efficacious grace. In virtue of holy obedience Lessius was commanded by the general to emend his original text in accordance with propositions dictated to him by Aquiviva. Lessius complied.
Representative of Lessius' spirituality is his little series of meditations called De summo bono et aeterna beatitudine hominis (Antwerp 1620). His cause for beatification has been introduced.
Bibliography: c. h. chamberlain, "Leonard Lessius," Jesuit Thinkers of the Renaissance, ed. g. smith (Milwaukee 1939). c. van sull, Léonard Lessius, S.J. (Louvain 1930). r. bÄumer, Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner, 10v. (Freiburg 1957–65) 6:981–982. c. sommervogel, et al., Bibliothèque de la Compagnie de Jésus, 11 v. (Brussels-Paris 1890–1932) 4:1726–1751. p. bernard, Dictionnaire de théologie catholique, 15 v. (Paris 1903–50) 9.1:453–454; 7.2:2135–2145.