Since the divine in us is certainly not vain, we need to know that we are ignorant. If we can attain this end completely, we shall attain 'learned ignorance'. For nothing becomes a man, even the most zealous, more perfectly in learning than to be found very learned in ignorance itself, which is his characteristic, and anyone will he the more learned the more he knows his own ignorance.

De docta ignorantia NICHOLAS OF CUSA

Everything craves its contrary, and not for its like", Socrates reports hearing a statesman say; "the dry craves for moisture, the cold for heat, the bitter for sweetness, the sharp for bluntness, the empty to be filled, the full to be emptied." This affirmation in the Lysis of the universal play of opposites in the realm of phenomena applies ironically to the history of the church in the fourteenth and fifteenth centuries. Innocent III, pope from 1198 to 1216, first realized the practical possibility of extending the spiritual and temporal rule of the church across the whole of Europe. His most spectacular success was the submission of England where, under John and Henry III, he ruled de jure and de facto through his legates. Those who followed him pursued the policies of an imperial papacy. Even as the attendant bureaucracy began to embrace the continent, two countervailing forces arose: the burgesses emerged as a business-oriented class with distinctly secular attitudes, whilst rulers and ministers who had once built kingdoms around their courts increasingly thought in terms of nation-states. The former mocked the religious decadence of a church flagrantly panting after gold, and the latter sought to divert that gold into national treasuries.

Intense struggle between cardinals and pope, loss of independence of bishops, and bitter disaffection amongst peoples ruled directly from the papal chair convulsed Italy. When Clement V, the archbishop of Bordeaux, became pope in 1305, he refused to leave France and instead established himself at Avignon. During the seventy-year 'Babylonian Captivity', French kings exercised such influence in the selection of popes and cardinals that other countries came to see the church as little more than another political tool in the struggles of the era. The eventual return to Rome in 1377 did not please the cardinals, who were mostly French and accustomed to the luxury and hedonism of Avignon. When Urban VI, an Italian, was elected pope and immediately pressed for stringent reforms within the church, thirteen cardinals withdrew, elected a second pope, Clement VII, and retired to Avignon under the protection of the French king. Thus began the Great Western Schism, which for four decades would make the papacy the laughing stock of the burgesses and the political puppet of France and the Holy Roman Empire. Each faction could sport a pope, a college of cardinals and its own bureaucracy for administration, most especially gathering taxes and tithes. Buying and selling favours, waging war and nepotism became primary papal business. Many churchmen and ordinary faithful began to look to some council of bishops and clergy to resolve the schism, reform practices and restore unity to the church. This confusion of sacred and secular, a warring chaos of religious, national and sectional politics, provided the context for a great spokesman for spiritual unity and temporal harmony, who saw that the roots of these troubles lay on a plane of noumenal reality and consciousness hardly recognized by those who willingly, violently elaborate their consequences.

Nicholas of Cusa was born in 1401 at the village of Cues (in Latin, Cusa) on the Moselle river, the son of Johann Cryfts (Krebs), a moderately prosperous owner of boats and vineyards. Little is known of his childhood beyond the persistent legend that his bookish nature and inability to handle a boat once enraged his father to the point of knocking him overboard with an oar. The place where this event occurred is still called the Schmeissgraben, 'river-blow'. Nicholas sought the protection of Count Theodoric von Manderscheid. The count took Nicholas in and eventually sent him to the school of the Brothers of the Common Life at Deventer in Holland. Drawing its inspiration from the mystic Jan van Ruysbroeck and even from Meister Eckhart, the school would come to number amongst its pupils Thomas a Kempis and Erasmus. Here the mystical dimension which numinously surcharged all his mature thoughts and actions flowered and began to bear fruit. During this time, dissident cardinals, exasperated with the disastrous double papacy, met at Pisa to resolve matters. Soon succumbing to the worldly politics they professed to abhor, they deposed as heretics Gregory XII, pope at Rome, and Benedict XIII, pope at Avignon, and proceeded to elect Alexander V, a third pope at Pisa. Alexander died within a year, and the same council elected a successor, John XXIII, a wily politician who had manipulated the council from its inception.

The general effect of these events upon the lay population nurtured the already rooted secular attitudes of the time. To Nicholas they were a tragedy. He left Deventer and became a student at the University of Heidelberg, an enthusiastic supporter of the conciliar movement. He was there when a new council convened at Constance in 1415, deposed John XXIII and Benedict XIII, and secured the resignation of Gregory XII. For two years the Council of Constance ruled the church, attempted some reforms, condemned the Bohemian reformer John Hus to the stake, and elected Martin V pope in 1417. Nicholas graduated from Heidelberg in 1416 and, in the midst of this unparalleled uproar, entered Italy's most famous university, Padua, where he met brilliant professors of mathematics, astrology, ancient Greek culture and canon law. The physician of Florence, Paolo Toscanelli, taught him, became his life-long friend, and was at his death-bed forty years later. After studying Padua's predominant philosophical viewpoints, those of Averroes and Aristotle, Nicholas rejected them for a richer Platonic perspective. In 1423 he became decretorum doctor, the highest degree in canon law. After a visit to Rome, he returned to the Rhineland and entered the University of Cologne. The archbishop made him an assistant, gave him an allowance and appointed him canon of the church of St. Simeon in Trèves.

Hardly had Nicholas begun his new duties when a thorny conflict emerged between a priest and the Elector Palatine, and Cardinal Orsini came to Germany as papal legate to settle the issue. Amongst the sixty legal opinions submitted to him was one written by Nicholas. Recognizing the insight and justice of the opinion, Orsini sought out Nicholas and soon made him his personal secretary. When the archbishop of Treves died, a dispute broke out over his successor. Eventually the cathedral chapter united behind one man of the von Manderscheid family and the pope appointed another individual archbishop. The conciliarists brought the dispute to the Council of Basel, and Nicholas journeyed there to plead the case for his foster family. Whilst at Basel he met many forerunners of the Italian Renaissance and even discovered a manuscript containing twelve lost plays of Plautus. Though he lost the case, he stayed on for some months effecting satisfactory compensation for the von Manderscheid family. More important, he presented his first book, De concordantia catholica, to the council. With the conciliarists, Nicholas held that the pope did not have sole power to create church law. "The authority of enacting canons depends," he wrote, "not on the pope alone, but on common agreement." In arguing that all legitimate bishops are equal with the bishop of Rome, he enunciated a profound political principle:

Since by nature all men are free, all government – whether based on written law or on law embodied in a ruler through whose government the subjects are restrained from evil deeds and their liberty regulated, for a good end by fear of punishment – arises solely from agreement and consent of the subjects.

In the face of obvious moral decay in the ecclesiastical hierarchy, greedy territorial conflicts amongst nobles and growing indifference to sacred matters amongst the populace, Nicholas saw the futility of attempting to impose unity through force. Harmony, if it were to be achieved, had truly to be universal, as the title of his book suggests.

As he rose in conciliar circles, Nicholas found time to consider the equinoctial drift of the Julian calendar, caused by its slight overestimation of the length of the solar year. The equinoxes were moving back through Julian calendar time at the rate of a week every nine hundred years. In De reparatione calendarii he argued for a method of calendrical stabilization which would require the omission of a leap year once every three hundred and four years to remain accurate. Though analysed earlier by Roger Bacon, it was not until 1582 that the Gregorian calendar, similar to that proposed by Nicholas, replaced the failing Julian system. Though such proposals were met with lethargy, respect for Nicholas came from every quarter. In addition to his previous appointments, he found himself elected dean of St. Mary in Oberwesel, dean of St. Florin at Koblenz and provost at Münstermaifeld. Already he had twice declined the chair of canon law at the University of Louvain. Nicholas, however, began to doubt the value of the councils, whose direction veered away from fundamental church reforms and towards acrimonious struggles with the pope. When Eugenius IV took the initiative in seeking a reunion of Greek and Latin churches, he suggested several meeting sites in Italy. The Greek response was gracious, but the council insisted on meeting in Basel, a site obviously inconvenient for the Greek delegation. Such petty behaviour revolted Nicholas, who saw in these negotiations a chance for Christian unity, and he joined the minority that accepted Italy. The council went on to elect a new pope in 1439, but the constituency of the council shifted increasingly towards the worse, and within a decade the conciliar pope resigned and the promising conciliar movement whimpered into oblivion.

Nicholas left Venice with the fleet sent to bring the Greek delegation to Italy. In Constantinople, Nicholas found the Greeks anxious to join with the West, in part for survival, but hesitant because of the complex struggle for authority between pope, council and various rulers. His wit, patience, skilful diplomacy and knowledge of Greek combined to persuade them. In 1437 he left Constantinople with the core of the Greek church, including the Byzantine emperor John VIII Palaeologos, the patriarch Joseph II, the primate of Russia, and patriarchs and archbishops from every major city. In Florence a union was effected on July 6, 1439. Nicholas had great hopes for this union – "The work of the Holy Spirit is unity and peace!" – but the actual result was ephemeral. The pope continued to struggle with the council whilst the Byzantine Empire was eroded by the voracious Ottoman Empire. Nicholas worked so hard to unite the church behind a papal authority which was not absolute that in 1446 Eugenius IV made him cardinal in petto (secretly, 'in the breast'). His successor, Nicholas V, did so publicly in 1450, giving him the cardinalate of San Pietro in Vincoli and the bishopric of Brixen. His countrymen were astounded, since few cardinals had been German, and Nicholas was everywhere enthusiastically received as Cardinalis Teutonicus.

During the jubilee year of 1450, Nicholas was appointed papal legate to the German nations and the Low Countries, and he travelled widely, settling issues, reforming monastic orders, and receiving and granting petitions and holding councils. In 1452 he turned to Brixen, where his interest in church reform could be most completely elaborated. He was horrified to find convents which had become little more than brothels holding lands for taxation. When he sought to replace a debauched abbess who did not even know the basic rules of her order, she sought the support of the Austrian archduke Sigismund. He gladly lent armies in exchange for land and favours, but Nicholas refused to capitulate. The conflict intensified until Nicholas was virtually imprisoned. His firmness compelled Sigismund to agree to an amicable settlement, but Nicholas was not to enjoy the fruits of his labours. His long-standing friend and fellow reformer, Aeneas Sylvius, ascended the papal throne as Pius II and immediately called Nicholas to his side.

In Rome, Pius II and Nicholas undertook fundamental reforms, but the times and human temperament were against them. Whilst Pius was out of the city, Nicholas governed Rome as vicarius generalis – the temporal authority of the papacy – with great success. Nicholas became involved in trying to win the cooperation of northern Italian nobles, in settling Hussite dissensions in Bohemia, and in examining the basis of Islam and preparing for possible Ottoman incursions (especially after the fall of Constantinople in 1453 and its total collapse in 1457). On his way to Ancona to further reconciliation with Bohemia, Nicholas suddenly fell ill at Todi. After lingering for three weeks, he died on August 11, 1464. Nicholas had quietly prepared for the end: with what wealth he could call his own, he had founded a hospital at Cues for thirty-three destitute elderly men as a place to be cared for until death. In addition, he reserved a room for the descendants of the von Manderscheid family, and he deposited his valuable library there, where it remains to this day. His body was buried in San Pietro in Vincoli, but his heart was interred before the altar in his hospital in Cues.

The immense energy Nicholas constantly poured into church reform at every level never obscured his philosophical clarity nor his subtle mysticism. For him, consciousness should ever seek Divine Unity, whilst action should have fraternal harmony as its purpose. The church, according to Nicholas, is a living unity, a fraternity united to the divine presence symbolized in Christ. As Deity is simple and also light, the shadows and reflections which constitute the world catch and transmit the light only to the degree that they form a universal harmony, the primary reflection of Divine Unity. Since Divine Light is simple and therefore the referent of only one Word, language and the categories of thought are necessarily engendered from experience of the realm of shadows. From this ontological perspective, two fundamental propositions follow:

All enquiry consists in comparative proportion, easy or difficult, and that is why the infinite, which as infinite escapes all proportion, is unknown. . . . [And] wisdom is hidden, and also the seat of intelligence, from the eyes of the living.

If maximitas, the quality of being maximum, can be attributed to whatever thing than which nothing can be greater, then it is a quality only of the infinite. If unity is a necessary correlate of infinitude, no quality can be opposed to maximitas; it coincides with the absolutely minimum. This is what "by the indubitable faith of all nations is accepted also as God". Deity, being maximitas, cannot be comprehended in any ordinary way, and the universal unity which comes from it is only partially comprehended by reason. Anyone who proposes to understand the fundamental nature of things

must raise the intelligence above the force of words themselves, rather than insist on the properties of words, which cannot be adapted properly to such great intellectual mysteries. It is necessary to use in a transcendental fashion examples so that the reader, leaving aside sensible things, should rise easily to simple intellectuality.

Knowledge, which is the province of the rational intellect, is concerned with proportionality, relationships between qualities, quantities and things.

Because it is clear in itself that there is no proportion of the infinite to the finite, from this it is most clear that where one finds something which exceeds and something which is exceeded, one does not arrive at the simple maximum, since what exceeds and what is exceeded are finite objects while the simple maximum is necessarily infinite.

Maximitas, beyond all proportionality, is unknowable by the ordinary modes of understanding. Yet one may approach ever closer to truth, just as proportions may approximate infinitude rather like a hyperbolic curve in a graph of a quadratic equation approaches, without ever reaching, some limit.

Therefore the understanding, which is not truth, never attains truth with such precision that it cannot be attained more precisely by the infinite; for it is to truth as the polygon is to the circle: the greater the number of angles inscribed in the polygon, the more it will be like the circle, but nevertheless it is never made equal to the circle, even if one multiplies the angles indefinitely.

Absolute knowledge is approached but never attained by the activities of the ratiocinative mind. Since the unitary Light which is the afflatus of the Divine is in man as well as Nature, there is an aspect of the understanding which is truth, unmoved by reasoning (which nevertheless can clear obscurations to it) but capable of being awakened by faith. For Nicholas, however, faith is not adherence to some set of dogmas, but is faith in Jesus as the symbolic expression of the Christos-light, the primordial radiance of Deity. Such faith is faith in the light within oneself, in Nature and in the noumenal realm which expresses the One whilst sustaining the many. Such faith permits a withdrawal from the senses and an awakening to experiential awareness of the essential nature of existence, the manifest effulgence of deus absconditus, ever-hidden Deity, and this faith is represented in Jesus.

For Jesus, blessed throughout the ages, end of all intellection, since he is Truth; end of all sensibility since he is Life; and ultimately of all being, because he is Entity; perfection of every created being as god and man, is incomprehensibly heard there as the limit of every word. From him proceeds, to him returns, every word.

Deity is therefore absolutely transcendent and absolutely immanent, the maximum and the minimum. Just as relative truth may increasingly approximate absolute truth, consciousness may transcend levels of understanding towards an absolute union with the Divine. The use of reason and ethical conduct in life, which aim to increase harmony amongst men and restore unity between man and Nature, clear away blockages and distractions that prevent transcendence. Because "every corporeal word is the sign of the spiritual Word, which is reason", the partial nature of ideas themselves can be used like stepping-stones to greater understanding.

Opposites suggest new levels of synthesis; Deity is the coincidentia oppositorum, the reconciliation of contraries. Thus Nicholas, who taught that knowledge in one sense is conjecture, held that a careful examination of Nature and human thought reveals contraries and contradictions that can guide one to ever greater understanding. He found time to study Islam in detail, to propose a method of squaring any circle, to argue for the rotation of the earth on its axis, and to propose that the universe is boundless in time and space. Harmony is understood, he professed, and unity achieved by loving each and every thing according to its place in the community of Nature. This is man's ethical work. In his later years he summed up his thought in a grand affirmation in De visione dei:

Now I behold as in a mirror, in an icon, in a riddle, life eternal, for that is naught other than that blessed regard wherewith Thou never ceasest most lovingly to behold me, yea, even the secret places of my soul. With Thee, to behold is to give life; 'tis unceasingly to impart sweetest love of Thee; 'tis to inflame me to love of Thee by love's imparting, and to feed me by inflaming, and by feeding to kindle my yearning, and by kindling to make me drink of gladness, and by drinking to infuse in me a fountain of life, and by infusing to make it increase and endure. 'Tis to cause me to share Thine immortality. . . . For it is the absolute maximum of every rational desire, than which a greater cannot be.

Drawing from Pythagoras, Dionysius the Areopagite, and Meister Eckhart, Nicholas of Cusa kept alive the mystic flame of intuition and passed it to individuals as different as Giordano Bruno and Copernicus. Whilst struggling for moral reform within a decaying structure, he subtly laid the foundation of human dignity upon which both the Renaissance and the Reformation would be built.