NICHOLAS OF CUSA. – Cardinal, philosopher, humanist scientist, born at Cues (Trevi) in 1401, died at Todi on 8 August 1464. His true name was Nicolaus Cryffts (Krebs = “crab,” a figure later incorporated into his cardinal’s coat of arms).
Having taken a degree in law in Italy, he returned to his homeland, stopping for a long time in Cologne, where he discovered not a few codices of ancient Greek and Latin works, including above all a codex containing Plautus’s *Menaechmi*, previously unknown (cod. Vat. lat. 3870). He therefore came into contact with the most notable humanists of his day: Cardinal Albergati, Tommaso Parentucelli (later NICHOLAS V), Aurispa, Traversari, and Aeneas Silvius Piccolomini (later PIUS II). He took part in the Council of Basel, initially as an advocate of the thesis defending the superiority of the council over the pope; he later adopted the opposing thesis, which he never abandoned and of which he became a staunch defender. He went to Constantinople as president of the embassy sent by the Council to promote the union of the Greek Eastern Church with the Latin Church. The result of the embassy was the Council of Florence, where the union was ratified. A close friend of Cardinal Cesarini, the papal legate at the Council, Nicholas of Cusa dedicated to him his major work, *De docta ignorantia*, written on the return journey from Constantinople. Created cardinal in 1450, he was sent by Nicholas V as papal legate and apostolic visitor to Belgium, Bohemia, and Germany; he consistently opposed everything that was contrary not only to faith but also to ecclesiastical discipline, which was not always respected at that time. This work appears all the more important in that it took place on the eve of the “Reformation.” He sought to combat Utraquism in Bohemia. While at the Council of Basel Nicholas of Cusa had favored a kind of compromise, formalized in the *Compactata*, which the Holy See never recognized, later he reacted energetically against the increasingly heterodox spirit alive in Bohemia. At the urging of Pius II, he attempted to combat Islam on the doctrinal level with the work *Cribratio Alchorani*.
In 1452 Nicholas of Cusa was elected to the see of Brixen. There he found himself opposed to Sigismund of Habsburg, count of the Tyrol, who sought to extend his dominion at the expense of the bishop’s rights, including territorial ones. Above all, he clashed with the enemies of the papacy, who had revealed themselves at Basel. He suffered persecution, personal insults, and imprisonment. The conflict, which threatened to become very serious, was ended by the intervention of Pius II through a compromise imposed also by the grave peril hanging over Europe after the fall of Constantinople into the hands of the Turks. Though remaining bishop of Brixen in law, Nicholas of Cusa was summoned to Rome by the pope as his vicar. Even in Rome, this man of austere habits found himself, because of his unyielding intransigence, at odds with the lifestyle of certain authorities, even ecclesiastical ones. He died a few days before Pius II. He left all his goods to the hospital he had founded at Cues, which he had endowed with a precious library and his manuscripts. He was buried in Rome in S. Pietro in Vincoli, where his monument, a work by A. Bregno, stands.
The most significant works of Nicholas of Cusa are: *De docta ignorantia*, in which his metaphysical system is expounded, centered on the incommensurability between the created infinity of God and human reason; *De coniecturis*, which develops the solution to the epistemological problem; *Idiotae libri quattuor*, in which the problem of knowledge is again addressed as it translates into a directive for life; the problem of the sciences is also treated, especially in the fourth book, entitled *De staticis experimentis*; *De beryllo*, in which the criterion of docta ignorantia is compared to a lens (beryl), through which alone the reality of things can be affirmed, things whose reason for being is found in the infinite; *De ludo globi*, in which the travail of thought in the conquest of truth is compared to the effort to reach with a ball the center of a device of nine concentric circles arranged in a spiral.
Nicholas of Cusa is of profound interest to culture as a humanist, philosopher, and scientist. The doctrinal sources from which he especially drew are the *Enneads* of Plotinus, the works of St. Augustine, the *De mystica theologia* and *De divinis nominibus* of the 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. Just as in action, after the deviation of his early years (documented by his work *De concordantia catholica*), he always fought for Rome with Rome, so in thought he was animated by the purpose, dictated by his faith, of tracing for himself and others the surest path that would lead man beyond discursive power (ratio) to the affirmation through the intuition of the intellect (intellectus) of the one and triune God. The actual infinity of God is not attainable in itself by human reason, 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 repose. Faith, which is precisely the concreteness of such intuition, as it is both a necessary moment and the supreme pinnacle of all human knowing, is also the first and ultimate determinant of being.
This immobile repose, that is, the actual infinity of God, in which all difference is annulled and opposites coincide (*coincidentia oppositorum*), is, however, unattainable by men. “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 St. Bonaventure), because the reason for it is clearly seen in the fact that man is other than God, an alterity therefore with respect to absolute Unity. This alterity, which does not posit itself, is among all the manifestations of absolute Unity the one most like God, and is more like God because, although lacking the power to bring things into being (which is proper to God alone), it is capable of reconstructing, for the purposes of knowledge, the creative rhythm of contraction and explication, from unity to multiplicity, until it surpasses every distinction in the concept of infinity proper to the intellect. Thus distinctions that are still compatible with reason are surpassed, just as reason surpasses distinctions of a sensible order. This process of unification is clearly evident in mathematical procedure: the regular polygon, which reason defines as different from the circumference, is intellectually identified with it if the number of sides is supposed to be infinite. The epistemological process of man thus retraces, for the purposes of knowledge, by an ascending path, that ontological rhythm which, by a descending path, is realized from absolute Unity to the multiplicity of real things. The actual infinity of God is in fact contracted in the world, which contains it only potentially, and in turn the universe is contracted in every finite being, in each of its parts, which is therefore implicitly the whole.
In accordance with such metaphysical conceptions stand the cosmological-scientific doctrines of N. C., who conceives scientific inquiry as the process of becoming aware of the entifying rhythm as it concretely unfolds in reality. The potential infinity of the world and of things forbids us to halt at a fixed limit, at a determined center of the cosmos. The world cannot have any center or any periphery, for to have these it would have to be in relation to something external, by which it would be limited, and would no longer be the entire world. Thus falls the teleological conception of the spheres revolving around the earth as the center of a finite cosmic system. Every point in infinity is a center, and since all things move, 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 area of the cycloid, and the quadrature 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 concerned himself with the spherical shape of the earth. He set forth his mechanical studies in the work *De staticis experimentis*, much appreciated by later scientists, including Descartes and Kepler.
There is no doubt as to the purity of N. C.’s intentions, as is also demonstrated by his numerous discourses and homilies, in which the steadfastness of his faith is fully evident. He was certainly an anti-Aristotelian, tending rather toward a Neoplatonic conception. Certain of his inclinations, therefore, detached from the general direction of his system, could easily lend themselves, as indeed happened (one need only think of Giordano Bruno, his great admirer), to pantheistic interpretations. Bruno in truth betrayed the spirit of the *Learned Ignorance*, inasmuch as it is an affirmation of transcendence, identifying the infinity of God with cosmic infinity. The scientific views of N. C. influenced the development of the sciences in Galileo, Descartes, and Kepler.