CUSANUS, NICOLAUS. - Cardinal, humanist philosopher and scientist, b. at Cues (Trier) in 1401, d. at Todi on 8 Aug. 1464. His real name was Nicolaus Criffis (Krebs = "crab," a figure later adopted in his cardinal's coat of arms).
Having taken his degree in law in Italy, he returned to his homeland, staying for a long time at Cologne, where he had the opportunity to discover not a few codices of ancient Greek and Latin works, among them first of all a codex containing previously unknown comedies of Plautus (cod. Vat. lat. 3870). He was therefore in contact with the best-known humanists of his time: Cardinal Albergati, Tomaso Parentucelli (later Nicholas V), Aurispa, Traversari, Enea Silvio Piccolomini (later Pius II). He took part in the Council of Basel, at first as a supporter of the thesis defending the superiority of the council over the pope; he then turned to the opposite thesis, which he never abandoned again and of which he became a strenuous defender. He was at Constantinople as president of the embassy sent by the Council to promote the union of the Greek Eastern Church with the Latin Church. The effect of the embassy was the Council of Florence, where the fusion was sanctioned. A close friend of Cardinal Cesarini, the Pope's legate at the Council, N. C. dedicated to him his major work, De docta ignorantia, written on the return journey from Constantinople. Appointed cardinal in 1450, he was sent by Nicholas V as legate and apostolic visitor to Belgium, Bohemia and Germany, always opposing everything that was in conflict not only with the faith but also with ecclesiastical discipline, which was not always respected at that time. This work appears all the more important in that it was carried out almost on the eve of the "Reformation." He sought to combat Hussitism in Bohemia. If at the Council of Basel N. C. was a supporter of a kind of compromise, fixed in the Compactata, which was however never recognized by the Holy See, later he reacted energetically against the increasingly heterodox spirit alive in Bohemia. On the advice of Pius II he sought to combat, in the doctrinal field, Islam, with the work Cribratio Alchorani.
In 1452 N. C. was elected to the see of Bressanone. Here he found himself confronted by Sigismund of Habsburg, count of Tyrol, who wanted to expand his own domain against the bishop's rights, including those of a territorial nature. Above all he found himself opposed to the enemies of the papacy, such as they had revealed themselves at Basel. He suffered persecutions, personal insults, imprisonment. The struggle, which threatened to become very serious, ended through the intervention of Pius II with a compromise imposed also by the grave threat hanging over Europe after the fall of Constantinople into the hands of the Turks. C., while remaining by right bishop of Bressanone, was called to Rome by the Pope as his vicar. Even in Rome C., a man of blameless morals, found himself, because of his indomitable intransigence, in conflict with the way of life of certain authorities, including ecclesiastical ones. He died a few days before Pius II. He left all his possessions to the growth of the hospital of Cues, which he had founded and endowed with a precious library and his manuscripts. He was buried in Rome in S. Pietro in Vincoli, where he has his monument, the work of A. Bregno.
The most significant works of N. C. are: the De docta ignorantia, in which his system of metaphysics is set out, centered on the disproportion between the creating Infinite of God and human reason; the De coniectoris, which develops the solution of the epistemological problem; Idiotae libri quattuor, in which the problem of knowing is again addressed insofar as it translates into a directive for life; the problem of the sciences is also treated there, especially in the fourth book, entitled De staticis experimentis; the De beryllo, in which the criterion of learned ignorance is compared to a lens (beryl), through which alone the reality of things can be affirmed, a reality that finds its reason for being in the infinite; the De ludo globi, in which the travail of thought for the conquest of truth is compared to the effort to reach with a ball the center of a device of nine circles arranged in a spiral.
N. C. deeply interests culture as a humanist, as a philosopher and as a scientist. The doctrinal sources from which he especially draws inspiration are the Enneads of Plotinus, the works of St. Augustine, the De mystica theologia and the De divinis nominibus of Pseudo-Dionysius, from which he derived the doctrine of negative theology. In philosophy he had an original thought, centered on the concept of the infinite. As in action, after the deviation of his early years, of which his work De concordantia catholica is a document, N. C. always fought for Rome with Rome; so in thought he had a lively purpose, dictated by his faith, of tracing for himself and for others the surest path that led man beyond discursive power (ratio), to the affirmation through the intuition of the intellect (intellectus), of God, one and three. The actual infinity of God is not attainable by human reason in itself, and can only be affirmed through mystical intuition, which gathers into a single center all the rays of existence and resolves the process of knowledge into an immobile quiet. Faith therefore, which is precisely the concreteness of such intuition, as it is a necessary moment, the supreme pinnacle of all human knowing, so is it the first and last determining factor of existence. Such immobile quiet, that is, the actual infinity of God, in which every difference is annulled and oppositions coincide (coincidentia oppositorum), is not granted to men to attain. "Learned ignorance" is precisely the knowledge of the limit of human thought. Such ignorance is "learned" (the expression is already found in St. Augustine and in St. Bonaventure), because its reason is clearly seen in function of the fact that man is other than God, an otherness therefore with respect to the absolute Unity. Such otherness, which does not posit itself, is among all the explications of the absolute Unity the most similar to God, and it is most similar because, although it lacks the power of giving being as regards existing, which belongs to God alone, it is nevertheless capable of reconstructing, as regards knowledge, the creative rhythm of contraction and explication, from unity to multiplicity, to the point of surpassing every distinction in the concept of infinity proper to the intellect. Thus the distinctions still compatible with reason are surpassed, just as reason surpasses the distinctions of the sensible order. This process of unification appears transparent in the mathematical procedure: the regular polygon, which reason defines as different from the circumference, is intellectually identified with it if the number of its sides is supposed infinite. Man's gnoseological process thus re-enacts, always as regards knowledge, by an ascending path that ontological rhythm which by a descending path is actualized from the absolute Unity to the multiplicity of real things. The actual infinity of God is in fact contracted in the world, which contains it only in potency, and in its turn the universe is contracted in every finite being, in every one of its parts which is therefore implicitly the whole.
In accord with these metaphysical conceptions stand the cosmological-scientific doctrines of N. C., who conceived scientific research as the process of becoming conscious of the rhythm of giving being as it is concretely actualized in reality. The potential infinity of the world and of things forbids us to stop at a fixed limit, at a determinate center of the cosmos. The world cannot have any center or any periphery, because, to have these, it would have to be in relation with something external, by which it would be limited, and it would no longer be the whole world. Thus the Ptolemaic conception of spheres centered on the earth, as the center precisely of a finite cosmic system, gives way. Every point in the infinite is a center, and since everything moves, the earth too moves in infinite space. C. also applied himself to the solution of mathematical problems, such as that concerning the ratio between circumference and diameter, the surface of the cycloid, the squaring of the circle. As a geographer, he was the first to draw a geographical map of Europe; a friend of Paolo Del Pozzo Toscanelli, he took an interest in the spherical shape of the earth. He set out his studies of mechanics in the work De staticis experimentis, so highly esteemed by the scientists who came after him, among them Descartes and Kepler.
There is no doubt about the purity of N. C.'s intentions, as is also demonstrated by the numerous discourses and homilies, in which the firmness of his faith appears in full. He was certainly an anti-Aristotelian, inclining rather to a conception of a Neoplatonic character. Certain of his attachments, therefore, torn from the general direction of the system, could easily lend themselves, as in fact happened (it suffices to think of Giordano Bruno, his great admirer), to pantheistic interpretations. Bruno indeed betrayed the spirit of "learned ignorance," insofar as it is an affirmation of transcendence, by identifying the infinity of God and the cosmic infinite. N. C.'s scientific views influenced the development of the sciences, in Galileo, Descartes, Kepler.
Bibliography6 works
Rend. della R. Acc. dei Lincei, classe di scienze morali, 6th series, 4 (1928), pp. 16-38; A. Hermet, Il C., Milan 1929; G. Saitta, La religione nel pensiero di N. da Cusa, in Annali dell'Università di Pisa, 12 (1929), pp. 42-60; T. Battaglia, Il significato dell'opera politica di N. da Cusa, in Studi in onore di Filippo Virgili, Rome 1935, pp. 96-115; R. Lazzarini, Il «De ludo globi» e la concezione dell'uomo nel C., Rome 1938, pp. 1-42; P. Rotta, N. C., Milan 1942 (with ample bibl.); R. Gradi, Il problema della conoscenza nel «De coniecturis» di N. da Cusa, in Sophia, 1941, pp. 247-59.