Nicholas of Cusa (1401-1464)

The greatest Catholic mind of the fifteenth century

The Latin fifteenth century did not produce a Saint Thomas or a Saint Bonaventure. It produced Nicholas of Cusa. No contemporary united as he did the breadth of the jurist, the finesse of the metaphysician, the daring of the scientist and the depth of the mystic.^[12] He read Greeks and Latins, Fathers and scholastics, mathematicians and astronomers; he gathered a remarkable personal library, still preserved today in his hospital at Cues^[13], and at Cologne he recovered ancient manuscripts — including Pliny's Natural History and comedies of Plautus.^[14]

This universality is not merely the curiosity of a collector. It serves a single intuition, which he unfolds in all his books: God's infinity infinitely exceeds every human measure, and this disproportion, far from discouraging the mind, is the very doorway to contemplation.

A cardinal, not a free agent

This must be said from the outset, because it governs the whole reading: Nicholas of Cusa is not an intellectual on the margins of the Church, nor a precursor of modern ruptures. He is a Churchman in the fullest sense: canonist, legate, cardinal, reforming bishop. His boldest thought is born within a life entirely given to the service of Catholic unity: reform of the clergy, return of the Greeks to unity, peace among peoples, defense of the papacy.

That is why he figures among the great figures of Catholicism, not among suspect geniuses. One does not “filter” Nicholas of Cusa: one distinguishes, in his later reception, what truly comes from him — a mysticism that seeks God beyond all words and all images, in full fidelity to the faith of the Church — from what others, such as Giordano Bruno, tried to make him say.^[15]

Biographical landmarks

The boatman's son from the Moselle

Nothing predestined this boatman's son for the Roman purple. Born in 1401 at Cues, on the Moselle, into a prosperous family of river boatmen, Nicholas Krebs bore the mark of that river and country throughout his life.^[20][21] Tradition says that as an adolescent he was entrusted to the Brethren of the Common Life at Deventer, the Devotio moderna movement from which the Imitation of Christ would also emerge.^[22] The Catholic Encyclopedia warns, however: of this Deventer schooling, “nothing is known”^[23]; and if this formation is real, its imprint would count: the affective, sober and interior piety of the Devotio moderna would be found at the heart of his mysticism, even in his most abstract speculations.

Grateful to his homeland, Nicholas founded there the St. Nikolaus-Hospital (Cusanusstift), a house for thirty-three poor elderly men — one for each year of Christ's earthly life — which still houses his library and his heart.^[24][25]

The jurist: Heidelberg, Padua and canon law

His formation was first that of a jurist. Enrolled at Heidelberg in 1416, he then went to Padua, then a capital of legal studies, where in 1423 he became a doctor of canon law.^[26] He completed his theological studies at Cologne.^[27] This canonical foundation explains his career: he first appears on the stage of the Church at the Council of Basel as the advocate of an episcopal cause, not as a theologian.

Basel: the conciliarist

In 1432 the young canonist sat at the Council of Basel, the great assembly that claimed to reform the Church and asserted the superiority of a council over the pope. There Nicholas wrote his first major work, the De concordantia catholica (1433), a masterly treatise on the “Catholic concord” of Church and Empire.^[28][29] At that point he defended a conciliarist thesis: the power of general councils prevailed over that of the pope.^[30]

This is the one point where one can speak of a position he would later abandon. In 1437, faced with the split between the council and the pope, Nicholas chose Eugene IV: the minority that remained faithful to the pope sent him to him.^[31] Basel, for its part, bogged down and radicalized after this departure — to the point of deposing Eugene IV (25 June 1439) and electing the antipope Felix V (5 November 1439).^[32]

Rallying to the pope and the embassy to Constantinople

From 1437 onward, Nicholas of Cusa broke with the radical party at Basel and placed himself on the side of Pope Eugene IV.^[33] This was not a career calculation: it was the conviction, matured through trial, that the unity of the Church needs a visible center. His adversaries saw betrayal; one may read in it the fidelity of a man who preferred the truth of communion to the logic of a system.

The pope immediately entrusted him with a delicate mission: bringing the Greeks back to unity. In 1437-1438 Nicholas was part of the small delegation sent to Constantinople, which obtained the adhesion of the emperor, the patriarch and twenty-eight archbishops to the future council of union.^[34][35] It was largely thanks to this mission that the Council of Florence would meet, where the reunion of the Greek and Latin Churches would be solemnly proclaimed — though alas fragilely (bull Laetentur caeli, 6 July 1439).^[36] On the return voyage Nicholas said he received the decisive light of his learned ignorance: a grace from above, he wrote, enabled him to “embrace the incomprehensible in a knowing ignorance.”^[37][38]

The reforming legate in Germany

Raised to the cardinalate by Nicholas V on 20 December 1448 and proclaimed cardinal-priest of San Pietro in Vincoli in 1449, Nicholas of Cusa became one of the great legates of reform in German lands.^[39][40] He traveled through the Empire, held synods, corrected abuses, restored clerical discipline, fought false devotions and false miracles. The man of the highest contemplation was also a demanding pastor, obsessed with the concrete reform of the Church well before the Council of Trent.

Cardinal and prince-bishop of Brixen: the conflict with Sigismund

In 1450 the pope appointed him prince-bishop of Brixen (Bressanone, in the Tyrol), a diocese that “needed a reformer.”^[41] But the reformer met a wall: the chapter resisted him, and above all the powerful Duke Sigismund of Austria refused to give up his rights over the local Church.^[42] The conflict worsened for years. Nicholas imposed the interdict; in 1460 Sigismund went so far as to have the cardinal arrested and forced him to compromise, before Nicholas escaped and reached Rome.^[43][44] The episode shows the concrete price of reform in the fifteenth century: whoever touches princely privileges risks prison.

Death at Todi

The final years saw him at the service of Pope Pius II, who appointed him vicar general of Rome and of the Patrimony of Saint Peter on 11 January 1459^[45]; indefatigable promoter of the crusade against the Turks. In August 1464, as he was traveling from Rome to Ancona for the crusade, illness overcame him: he died at Todi, in Umbria, on 11 August 1464.^[46][47] The 1911 Catholic Encyclopedia gives a slightly different sequence — the cardinal is said to have accompanied Pius II to Ancona before being sent to Leghorn to urge on the Genoese crusaders — and specifies that he died surrounded by his friends, the physician Toscanelli and Bishop Johannes Andreæ.^[48] His body was laid in his Roman basilica of San Pietro in Vincoli^[49]; his heart, according to his wish, returned to Cues, in the hospital for the poor that he had founded.^[50]

“Knowing that one does not know”

The heart of Nicholas of Cusa's philosophy lies in a paradox: the highest science of God is a learned ignorance. Not the ignorance of the lazy, but that of the sage who has understood that God's infinity infinitely exceeds every measure of reason.^[51][52] From the infinite to the finite, he writes, there is no proportion; yet to know is to measure, compare and proportion. Since God has no proportion to the created, he cannot be “measured” by any concept: the truest knowledge we can have of him is to know that he surpasses us absolutely.

“From the infinite to the finite there is no proportion.” — Nicholas of Cusa, On Learned Ignorance, I, 3^[53]

This intuition is not skepticism. It is, on the contrary, the condition of true adoration: the more the mind recognizes that God exceeds it, the more it opens itself to what in God can never be enclosed. Learned ignorance is the philosophical name for the humility of intelligence before mystery.

The coincidence of opposites

From this disproportion follows Cusa's most famous thesis: in God, opposites coincide. What our reason separates — maximum and minimum, center and circumference, whole and part — comes together in the divine infinite, where there is no longer greater or lesser.^[54][55] God is the Absolute Maximum who, being without limit, is also the Minimum: for that which can neither be increased nor diminished is, at once, the greatest and the least possible.

This is the famous coincidentia oppositorum, the coincidence of opposites. It does not abolish the principle of non-contradiction in the world of finite things; it marks only the boundary where ordinary logic, made for the finite, must bow before the infinite. God dwells beyond the field where reason opposes contradictories, where discursive reason can no longer follow him and where only contemplative intelligence can, in a luminous night, glimpse him.^[56]

God enfolds, the world unfolds

To express the relation between God and the world without confusing them, Nicholas forged a pair of terms that became classic: complicatio and explicatio. God enfolds (complicatio) in himself, in simple unity, everything that exists; the world unfolds (explicatio) in time and space what God contains eternally.^[57] The created order is therefore neither God nor a mere nothing: it is a contracted maximum, a finite reflection of the infinite, in which God shows himself in all things and everywhere without ever dissolving into things.

This is where the whole charge of pantheism against him is decided: does Cusa come close to identifying God and the world? We shall see below that he does not, but that an attentive reader is needed in order not to mistake him.

Nicholas of Cusa is not only a metaphysician. His most beautiful pages are pages of prayer. He extends the negative theology of the Pseudo-Dionysius — one of his acknowledged roots^[58] — and places it at the service of a burning contemplative experience. He also meditates on John Scotus Eriugena and Meister Eckhart, setting aside what the Church censured in them (see the neighboring articles).

The Vision of God: the icon with the all-seeing gaze

In 1453 he sent the Benedictine monks of Tegernsee a moving little book, De visione Dei (The Vision of God), accompanied by a painting: the portrait of a face — an icon — whose gaze seems to follow every viewer, wherever he stands.^[59] Let ten monks distribute themselves around the image: each will believe himself looked at alone, and yet all will be looked at at the same time. From this simple optical exercise Nicholas draws a theology of the divine gaze of rare intensity: “Your gaze, Lord, is your face” (ch. VI); “in looking at me, you give yourself to be seen by me, you the hidden God” (ch. V); and his seeing, for God, is loving (ch. VII).^[60]

God sees me, and his gaze makes me be; he sees me entirely, without ever turning away; and for him to see me is to love me. Contemplation becomes a face-to-face in which man discovers that he is first a seen one, a loved one, before he is a seer.

The wall of paradise

To say where God dwells, Nicholas takes up an image that would remain famous: the wall of paradise (murus paradisi).^[61] Around the garden where God dwells runs a wall, and this wall is made of the coincidence of opposites. As long as the mind reasons, it remains outside, halted by contradiction; only by crossing this wall — by accepting that there maximum and minimum, being and non-being coincide — does it enter the region where God can be glimpsed. The gate of paradise is guarded, he writes in chapter IX, by “the highest spirit of reason” (spiritus altissimus rationis): as long as this guardian is not overcome (qui nisi vincatur), the entrance does not open (non patebit ingressus).^[62]

This is not pure speculation: it is the experience of all the great contemplatives, translated into philosophical language. Where Saint John of the Cross would speak of the “dark night,” Nicholas speaks of wall, cloud and luminous ignorance. The same mountain, climbed by a geometer.

The most surprising thing about this mystic is the scientist. Nicholas of Cusa, a century before Copernicus, maintained cosmological theses of extraordinary daring — not by observation, but by metaphysical deduction from the infinity of God.^[63][64]

A universe without center or edges

Since God alone is infinite and perfectly exact, no created reality can be the absolute center of the world or occupy its exact circumference.^[65] The universe, image of the divine infinite, therefore has no fixed center and no assignable edge: it is interminatum, without precise limit. Nicholas takes up the old formula applied to God and extends it to the cosmos: a sphere “whose center is everywhere and whose circumference is nowhere.”^[66]

“The machine of the world will have its center, so to speak, everywhere, and its circumference nowhere.” — Nicholas of Cusa, On Learned Ignorance, II, 12^[67]

The Earth, “a noble star”

He draws from this a consequence astonishing for his time: the Earth is not motionless at the center of the world. It moves, like the other bodies; it is neither the lowest point nor the vilest thing in the universe, but “a noble star,” endowed in its own way with light, heat and influence.^[68][69] Nothing that exists, he writes, is perfectly at rest.

The novelty must be measured: a century before Copernicus published, the future cardinal was already teaching serenely that the Earth moves and occupies no privileged place in space. And he did so without the Church taking alarm, because he did so as a theologian of the divine infinite, not as a polemicist. This is a useful reminder: the later trial of Galileo does not tell the whole story of the Church's relation to science; Cusa's example shows a Church that shelters, honors and raises up one of the boldest cosmologists in history.

The calendar reformer and the mathematician

This concrete mind did not merely speculate about the heavens: he wanted to set them back on time. As early as 1436, in a memorandum to the council (Reparatio kalendarii), Nicholas proposed a reform of the calendar to correct the drift of the equinoxes — a project that foreshadowed, by more than a century, the Gregorian reform of 1582.^[70] A passionate mathematician, he devoted several treatises to the squaring of the circle, seeking in geometry itself an image of the condition of the mind before truth: the inscribed polygon that, by multiplying its sides, approaches the circle indefinitely without ever equaling it — as the intellect approaches truth without ever measuring it exactly (De docta ignorantia, I, 3, n. 10).

The table below summarizes the major works of this many-sided genius.

In 1453, the news shook Christendom: Constantinople had fallen to the Turks (see The fall of Constantinople). Under the shock, Nicholas of Cusa wrote De pace fidei (The Peace of Faith) in a single impulse, one of the most discussed texts of his work.^[71][72]

A heavenly dialogue

The book stages a heavenly assembly: under the guidance of the Word, seventeen sages of the nations — a Greek, an Italian, an Arab, an Indian, a Chaldean, a Jew, a Scythian, a Frenchman, a Persian, a Syrian, a Spaniard, a German, a Tartar, an Armenian, a Bohemian, an Englishman — and a Turk debate the religions of the world.^[73] From the very first chapter, in the angel's supplication, is uttered the famous formula: una religio in rituum varietate — “one religion in the variety of rites” (I, 6).^[74]

“There is one religion in the variety of rites.” — Nicholas of Cusa, The Peace of Faith, I, 6^[75]

What Cusa says — and what he does not say

This phrase was later appropriated by a religious relativism that is not Cusa's. The text must be read closely to avoid the misunderstanding. Nicholas does not say that all religions are equal, nor that Christ is one path among others. His dialogue is presided over by the Word of God; the “one religion” that appears beneath the rites is the one truth whose fullness is Christianity. Diversity of rites is legitimate; truth is one, and it has a name: Christ.

Such is the Catholic reading proposed here: God leaves no people without some share of light, and every sincere religious search is, obscurely, a search for Christ — but that light is fulfilled only in the true faith. De pace fidei is therefore not a manifesto of indifferentism; it is an appeal to peace through the conversion of hearts to the one truth, written by a man who, as legate in Germany, had preached the Jubilee indulgence and the crusade against the Turks.^[76] To read it as a plea for the equivalence of religions is to betray it.

The accusation of pantheism: Wenck and the Apologia

As soon as On Learned Ignorance appeared, a theologian of Heidelberg, Johannes Wenck, violently attacked Nicholas in a pamphlet, the De ignota litteratura (“On unknown learning,” 1442-1443): in his view, learned ignorance and the coincidence of opposites derive from Meister Eckhart — he quotes three German excerpts from Eckhart, drawn from the Little Book of Benediction (Liber benedictus) and German sermons 2 and 6 — and revive doctrines targeted by Eckhart's condemnation in In agro dominico (1329).^[77] This is the strong form of the charge: by making God and the world coincide, does Cusa not fall into pantheism, the confusion of God and creature? Nicholas replied in 1449 with an Apologia doctae ignorantiae (“Defense of learned ignorance”), where he clarified his thought and showed that it stood in the line of the Fathers and negative theology.^[78]

The point is decisive, and it is settled clearly: the coincidence of opposites and the contracted maximum are not pantheism. Cusa always maintains the absolute transcendence of God — God enfolds the world, but the world is not God; God is reflected in everything, but dissolves into nothing. His formula of the non aliud, the “Not-Other,” says precisely this: God is not one thing among things, not even “other” than things in the way creatures are other than one another. He is beyond the very opposition of same and other.

Bruno and an equivocal reception

The misunderstanding nevertheless has a history. A century and a half later, the apostate Giordano Bruno would seize upon Cusa's infinite universe and coincidence of opposites to build, for his part, a real pantheism in which God is confused with an infinite and eternal cosmos.^[79] Similarity of words made some believe in a filiation of doctrines. But between the contemplative cardinal and the heretic burned in 1600, the difference is radical: in Cusa, the “boundless” universe is the sign of a God who alone is truly infinite; in Bruno, it becomes a substitute for God. The same image serves adoration in one, negation in the other. That is why Cusa must be read in himself, not through those who captured him.

The judgment passed on his work

Nicholas of Cusa was never condemned: he was made cardinal, bishop, legate. The author of the Catholic Encyclopedia (1911) article considers that “the context of his writings proves that they are all strictly Christian”^[80] — an encyclopedia's opinion, not a judgment of the Church. The act that counts is the message of John Paul II of 15 May 2001, which pays tribute to Cusa and to his service of the Church.^[81]

“The context of his writings proves, however, that they are all strictly Christian.” — The Catholic Encyclopedia, on the bold formulas of Nicholas of Cusa^[82]

Nicholas of Cusa is therefore not a suspect master tolerated half-heartedly, but a faithful genius whose boldness is carried by faith. His body was buried in his Roman basilica of San Pietro in Vincoli^[83], and his heart rests in the hospital at Cues^[84]; he was never canonized, and no cause is attested in the sources consulted.

Nicholas of Cusa's itinerary speaks forcefully to the believer today.

First, he teaches the humility of intelligence. In an age intoxicated with its knowledge, learned ignorance reminds us that the highest science is not to explain everything, but to recognize what infinitely surpasses us. The true scholar is not the one who reduces God to his concepts; it is the one who, having learned everything, bows before mystery. As Saint Paul says:

“For we now see in a mirror, in an enigma, but then face to face. Now I know in part, but then I shall know even as I am known.” — Saint Paul, 1 Corinthians 13:12^[85]

Then, he shows that faith and reason do not fight each other. Cardinal and cosmologist, contemplative and mathematician, Nicholas embodies the Catholic ideal of an intelligence that seeks God with all its strength, without ever opposing laboratory and oratory. His “noble star” Earth and his icon with the all-seeing gaze come from the same pen, because they seek the same God.

Finally, he offers the example of an obedient boldness. Nicholas of Cusa dared the most audacious thoughts of his century — but always in the Church, never against her. He preferred communion to his own system, leaving conciliarism when truth required it. That is his deepest lesson: the freest intelligence is the one that accepts receiving itself from another — from the Church, and from God.

Gratitude and admiration remain: a boatman's son who became a prince of the Church, a mystic who became a scientist, a genius who became a servant. The highest flight of human reason, here, did not leave the ground of faith; it began there, and returned there.

• Pseudo-Dionysius the Areopagite (5th-6th century) — the source of the negative theology of which Cusa is the boldest heir.
• Meister Eckhart (c. 1260-c. 1328) — the great Rhineland mystic whose intuition of God beyond every concept Cusa extends — with the reservation imposed by the censure of twenty-eight of his propositions by John XXII (In agro dominico, 1329).
• John Scotus Eriugena (c. 800-c. 877) — the Neoplatonic philosopher of the early Middle Ages, another link in the lineage to which Cusanus belongs — whose Periphyseon was burned by order of Honorius III (1225).
• The Council of Florence (1431-1449) — the council of Greek-Latin union, made possible by the pontifical delegation to Constantinople — of which Cusa was part.
• The fall of Constantinople (1453) — the event that inspired De pace fidei.
• Origen (c. 185-c. 253), Eusebius of Caesarea (c. 265-339), Tertullian (c. 155-c. 220) — the “to-be-filtered” geniuses of the ancient Church, to whom Cusa offers the counterpoint: fully faithful boldness.