Suárez's writings include treatises on law, the relationship between Church and State, metaphysics, and theology. He is considered the godfather of International Law. His Disputationes metaphysicae (Metaphysical Disputations) were widely read in Europe during the 17th century and are considered by some scholars to be his most profound work. Suárez was regarded during his lifetime as being the greatest living philosopher and theologian, and given the nickname Doctor Eximius et Pius ("Exceptional and Pious Doctor"); Pope Gregory XIII attended his first lecture in Rome. Pope Paul V invited him to refute the arguments of James I of England, and wished to retain him near his person, to profit by his knowledge. Philip II of Spain sent him to the University of Coimbra in order to give it prestige, and when Suárez visited the University of Barcelona, the doctors of the university went out to meet him wearing the insignia of their faculties. After his death in Portugal (in either Lisbon or Coimbra) his reputation grew still greater, and he had a direct influence on such leading philosophers as Hugo Grotius, René Descartes, John Norris, and Gottfried Leibniz. In 1679 Pope Innocent XI publicly condemned sixty-five casuist propositions, taken chiefly from the writings of Escobar, Suárez and others, mostly Jesuit, theologians as propositiones laxorum moralistarum and forbade anyone to teach them under penalty of excommunication. Philosophical thought His most important philosophical achievements were in metaphysics and the philosophy of law. Suárez may be considered the last eminent representative of scholasticism. He adhered to a moderate form of Thomism and developed metaphysics as a systematic enquiry. Metaphysics For Suárez, metaphysics was the science of real essences (and existence); it was mostly concerned with real being rather than conceptual being, and with immaterial rather than with material being. He held (along with earlier scholastics) that essence and existence are the same in the case of God (see ontological argument), but disagreed with Aquinas and others that the essence and existence of finite beings are really distinct. He argued that in fact they are merely conceptually distinct: rather than being really separable, they can only logically be conceived as separate. On the vexed subject of universals, he endeavored to steer a middle course between the realism of Duns Scotus and the nominalism of William of Occam. His position is a little bit closer to nominalism than that of Thomas Aquinas. Sometimes he is classified