The Medieval Church c. AD 590 – 1517 · monasticism, scholasticism, the sacramental system · preservation and accumulation
The medieval church spans roughly nine centuries — from the death of Gregory the Great in 604 (or alternatively from the rise of Islam in the 630s and the consequent collapse of the Eastern Mediterranean Christian heartland) to the eve of the Reformation in 1517. The period is conventionally divided into three phases: the early medieval / Carolingian phase (c. 590 – 1050), during which the collapsing Western Roman world was substantially Christianised through monastic and missionary work; the high medieval phase (c. 1050 – 1300), during which the Western church reached the height of its institutional, intellectual, and artistic achievement under the developed papal monarchy, the rise of the universities, the great scholastic syntheses (Anselm, Aquinas, Bonaventure, Scotus), and the artistic flowering of Romanesque and Gothic architecture and sacred music; and the late medieval phase (c. 1300 – 1517), in which the institutional and intellectual structures of high medieval Christendom began to strain under the Avignon Papacy and the Great Western Schism, the Black Death, the rise of nominalist scholasticism, the pre-Reformation movements (Wycliffe, Hus, the Waldensians, the conciliarist movement), and the gathering pressures that would produce the Reformation. Across the entire period the Eastern Christian world followed a different trajectory: the Byzantine theological tradition through Maximus the Confessor, John of Damascus, the iconoclastic controversies (8th–9th c.), the Photian schism and the Great Schism of 1054, the hesychast controversy and Palamas (14th c.), and the eventual fall of Constantinople to the Ottoman Turks in 1453. The Reformed Christian reads the medieval period with both substantial gratitude — for the preservation of the canon and the creeds, the conversion of the European populations, the great mystical-devotional tradition, the substantive theological achievements of the scholastic period, and the pre-Reformation gospel witness in figures like Wycliffe, Hus, and the Waldensians — and substantial discernment about the accumulation of error that the Reformation would have to address: the developed papal monarchy, transubstantiation, the seven-sacrament system, the doctrine of merit and indulgences, the Marian and saint devotion that had grown beyond biblical warrant, the persecution of dissent through inquisitions and crusades. The medieval church is neither the wholesale darkness the cruder Protestant polemic has sometimes presented nor the unalloyed flowering the cruder Catholic apologetic sometimes describes; it is the long, complex, substantively Christian period in which the gospel was preserved and transmitted, alongside accumulations of error the Reformation would have to face.
WHY THIS PAGE EXISTS — The medieval period is referenced briefly across the Sola Fide pillars — the Eras survey, the Reformation page (as the immediate prelude), the Creeds and Confessions survey, the Systematic Theology pillar. None of those gives the focused historical-theological treatment of the era that a serious enquirer needs. This page does that work: (1) the timeline of the nine medieval centuries; (2) the political and ecclesial setting — the conversion of Europe, the collapse of the Eastern Mediterranean Christian heartland under Islam, the rise of Western Christendom; (3) the principal figures — Gregory the Great, Anselm, Bernard of Clairvaux, Aquinas, Bonaventure, Eckhart, Catherine of Siena, Wycliffe, Hus, à Kempis; (4) the doctrinal developments — the sacramental system, the developed Roman papal monarchy, transubstantiation, the doctrine of merit, the Marian and saint devotion; (5) worship, piety, and church order — monasticism, the mendicant orders, the liturgy, the medieval mystical tradition; (6) the controversies — iconoclasm, the Great Schism (1054), the conciliarist movement, the pre-Reformation movements; (7) the theological stakes for the contemporary Reformed reader; (8) the hard places — the persecution of dissent, the crusades, the inquisitions, the doctrinal accretions; (9) the influence on the Reformation and subsequent Christianity; (10) the modern parallels and lessons. The tone is grateful, careful, and substantively engaged. The medieval period is the longest single period in Christian history and one of the most contested in Protestant memory; the careful Reformed reading neither demonises the medieval church (which preserved the canon, the creeds, and substantial catholic Christianity through nine centuries) nor canonises the medieval church (whose accumulated errors the Reformation had to address). Both judgements have to be held together.
Read the medieval period as substantive Christian history, not as the wholesale "Dark Ages" of cruder Protestant memory. The Protestant historiographical tradition has sometimes presented the medieval period as nine centuries of spiritual darkness from which the Reformation rescued the church. This caricature is unfaithful to the historical record. The medieval church preserved the canon of Scripture, the ecumenical creeds, the substantive patristic theological tradition, and the gospel of grace (however imperfectly applied) across nine centuries. The substantial Christianisation of Northern Europe through Anglo-Saxon, Frankish, and Slavic missionary work; the substantive theological achievements of Anselm, Bernard, Aquinas, and Bonaventure; the architectural and artistic flowering of the Romanesque and Gothic cathedrals and of medieval sacred music; the pastoral ministry of countless monasteries, parishes, and household devotions — all this is substantively Christian and deserves the Reformed reader's grateful recognition. R. W. Southern's Western Society and the Church in the Middle Ages (Penguin, 1970) remains one of the great accessible introductions to the period.
Read it also as the substantive accumulation of errors the Reformation had to address. The Reformed reading does not soften the substantive doctrinal accretions that the medieval church developed beyond apostolic warrant: the developed papal monarchy from Gregory VII through Innocent III to Boniface VIII; the formal definition of transubstantiation at Lateran IV (1215); the developed seven-sacrament system articulated by Peter Lombard and consolidated by Aquinas; the doctrine of merit, the treasury of merit, and the indulgences system that would explode in the 1517 controversy; the developed Marian devotion (the doctrine of the Immaculate Conception, defined formally only in 1854 but circulating in medieval devotion from the 11th c.); the saint devotion that had grown beyond biblical warrant; the venial-mortal sin distinction; the developed doctrine of purgatory. These developments — even where they had some substantive theological foundation in the patristic tradition or in genuine pastoral concerns — were accretions the Reformation had to address. The Reformed reader reads the medieval period without softening this. Steven Ozment's The Age of Reform 1250–1550 (Yale, 1980) is the standard treatment of the long road to the Reformation.
Read the medieval theological tradition substantively, especially Anselm and Aquinas. The Reformed evangelical engagement with the medieval theological tradition has substantively recovered in the past two decades. Anselm's Cur Deus Homo (Why God Became Man, c. 1098) is the foundational medieval treatment of the atonement and a substantive ancestor of the Reformed penal-substitutionary doctrine. Aquinas's Summa Theologiae is the great medieval synthesis of patristic Christian theology with Aristotelian philosophy; while the Reformed tradition contests certain Thomistic conclusions (especially on the merit-system and the sacramental theology), the substantive theological framework of the Summa — its doctrine of God, its careful Christology, its substantial doctrine of grace — has been the object of substantial recent Reformed retrieval (Steven Duby, Matthew Levering's engagement with Reformed theologians, Carl Trueman, and others). The careful Reformed engagement with Aquinas distinguishes the substantive theological work (much of which the Reformation received) from the specific medieval Roman developments the Reformation contested. Heiko A. Oberman's The Harvest of Medieval Theology: Gabriel Biel and Late Medieval Nominalism (Harvard, 1963) is the classic Reformed-engagement scholarly treatment of late medieval theology.
Read the pre-Reformation movements as the medieval gospel witness. The pre-Reformation movements — the Waldensians from the 12th c., Wycliffe and the Lollards in 14th-c. England, Jan Hus and the Hussites in 15th-c. Bohemia, the various proto-Reformation reform movements — are the medieval expression of the same gospel concern the Reformation would consolidate. The Reformed reader reads these movements with substantial gratitude: they were the gospel witness within the medieval church, often paying with their lives (Hus was burned at the stake at the Council of Constance in 1415; the Waldensians were persecuted across centuries; Wycliffe's bones were exhumed and burned posthumously in 1428). The Reformed evangelical tradition stands in substantive continuity with the pre-Reformation gospel witness. See The Reformation.
1. Timeline and historical overview
pope
collapse of Eastern Mediterranean Christianity
controversies
Holy Roman Emperor
monastic schools
(Prince Vladimir)
(East-West)
(papal monarchy)
(begins crusading period)
(substitutionary atonement)
monastic reform
(Bologna, Paris, Oxford)
(Peter Waldo)
(papal monarchy at height)
founded
transubstantiation defined
(unfinished)
("Babylonian Captivity")
(c. one-third of Europe dies)
two and three rival popes
and Lollard movement
Hus burned 1415
papal restoration
to Ottoman Turks
printing press
(Florence reformer)
(end of the era)
The principal modern scholarly resources are R. W. Southern, Western Society and the Church in the Middle Ages (Penguin, 1970), The Making of the Middle Ages (Yale, 1953), and Saint Anselm: A Portrait in a Landscape (Cambridge, 1990); Peter Brown, The Rise of Western Christendom (3rd ed., Wiley-Blackwell, 2013); Diarmaid MacCulloch, Christianity: The First Three Thousand Years (Penguin, 2009), the substantial medieval sections; Steven Ozment, The Age of Reform 1250–1550 (Yale, 1980); Eamon Duffy, The Stripping of the Altars: Traditional Religion in England 1400–1580 (Yale, 1992); Norman Tanner, The Church in the Later Middle Ages (I.B. Tauris, 2008); Frances Young, Lewis Ayres, and Andrew Louth, eds., The Cambridge History of Early Christian Literature (Cambridge, 2004); G. R. Evans, The Medieval Theologians (Wiley-Blackwell, 2001); Heiko A. Oberman, The Harvest of Medieval Theology: Gabriel Biel and Late Medieval Nominalism (Harvard, 1963; rev. ed. 2000); Carl R. Trueman and the broader Reformed-evangelical engagement with medieval theology. For the Eastern medieval tradition: John Meyendorff, Byzantine Theology (Fordham, 2nd ed. 1979); Andrew Louth, Greek East and Latin West (St Vladimir's Seminary Press, 2007). For accessible Reformed engagement: Justo González, The Story of Christianity, vol. 1 (HarperOne, 2nd ed. 2010); Bruce Shelley, Church History in Plain Language (5th ed., Nelson, 2020); Nick Needham, 2000 Years of Christ's Power, vols. 2–3 (Christian Focus / Grace Publications, rev. ed. 2016–2019).
2. Political and ecclesial setting
The collapsing Western and the rising Carolingian world (c. 590 – 1000)
The medieval period opens with the collapse of the Western Roman Empire substantially completed (the deposition of the last Western emperor occurred in 476, more than a century before the conventional medieval start) and with the Western Mediterranean Christian world adapting to life among the Germanic kingdoms. Pope Gregory the Great (590 – 604) is a hinge figure: substantively a late patristic Latin theologian (in the Augustinian tradition); pastorally a medieval church-builder negotiating with the Lombard Germanic kings and dispatching missionaries to convert the Anglo-Saxon kingdoms of Britain (the mission of Augustine of Canterbury in 597); ecclesially a developer of the Roman administrative structure that would become the medieval papacy. The seventh and eighth centuries saw the Christianisation of the Anglo-Saxon kingdoms, the Frankish Carolingian dynasty's adoption of Catholic Christianity, the Boniface (Apostle of Germany) missionary work in the German lands, the Iro-Scottish monastic missions to the Continent, and the gradual Christianisation of much of Northern Europe. Charlemagne's coronation as Holy Roman Emperor on Christmas Day 800 was the political-symbolic founding of a Western Christian commonwealth that the high medieval period would inherit.
The rise of Islam and the collapse of Eastern Mediterranean Christianity
The most consequential geopolitical event of the early medieval period for global Christianity was the rise of Islam from the 630s onward. The Arab conquests within a single generation overran the Christian heartlands of the eastern Mediterranean — Syria-Palestine (635 – 640), Egypt (639 – 642), North Africa across the next half-century. The patriarchates of Alexandria, Antioch, and Jerusalem came under Muslim rule; the substantial Christian populations of these regions gradually became minorities; the centre of Eastern Christianity moved north to Constantinople (which survived as the Byzantine capital until 1453) and east to the Christian kingdoms of Armenia, Georgia, and Ethiopia. The collapse of the Eastern Mediterranean Christian heartland — one of the great catastrophes of Christian history — reshaped the medieval Christian world. The Western Latin church, less directly affected, became the substantial centre of Christian civilisational continuity in the high medieval period.
The high medieval Western Christendom (c. 1050 – 1300)
The high medieval period saw the Western Latin church reach the peak of its institutional, intellectual, and cultural achievement. The Gregorian Reform of the 11th c. (under Gregory VII, 1073 – 1085) substantially asserted the autonomy of the church from lay (royal/imperial) appointment of bishops and abbots and consolidated the papal monarchy. The Crusades (1095 – 1291; eight major crusades plus continuing smaller ones) attempted to recover the Christian Holy Land from Muslim rule and produced both substantive Christian-Muslim military engagement and substantive Western-Eastern Christian tensions (the Fourth Crusade's sack of Constantinople in 1204 was a particularly catastrophic event in Christian history). The rise of the universities (Bologna 1088, Paris c. 1150, Oxford c. 1167, others) transformed Christian intellectual life. The mendicant orders (Franciscans 1209, Dominicans 1216) provided substantive urban ministry and theological scholarship. The great scholastic theologians (Anselm 1033 – 1109; Peter Lombard d. 1160; Bonaventure 1221 – 1274; Aquinas 1225 – 1274; Duns Scotus c. 1265 – 1308) produced the synthesis of patristic Christian theology with Aristotelian philosophy that has shaped Western thought ever since. The high Gothic cathedrals and the medieval sacred-music tradition (Gregorian chant and its developments) are the artistic flowering of this period.
The late medieval crises and the road to the Reformation (c. 1300 – 1517)
The late medieval period saw substantial strain in the institutional and intellectual structures of high medieval Christendom. The Avignon Papacy (1309 – 1377), in which the popes resided in Avignon (in French territory) rather than Rome, was seen by contemporaries as the "Babylonian Captivity" of the church. The Black Death (1347 – 1351) killed roughly one-third of the European population, producing substantial social, economic, and religious disruption. The Great Western Schism (1378 – 1417) saw two and at times three rival popes simultaneously claiming to be the legitimate successor of Peter, with the European kingdoms divided in their allegiance. The conciliarist movement of the 1410s (the Councils of Pisa 1409, Constance 1414 – 1418, Basel 1431 – 1449) attempted to assert the authority of general councils over the papacy and produced significant theological-ecclesiological tension. The pre-Reformation movements — Wycliffe (c. 1330 – 1384) and the Lollards in England; Hus (c. 1369 – 1415) and the Hussites in Bohemia; the Waldensians in their continuing existence; the various northern German devotional reform movements — pressed substantive concerns about clerical corruption, the sale of indulgences, the use of the vernacular Bible, the doctrine of the church, and the gospel of grace that the Reformation would consolidate. The fall of Constantinople to the Ottoman Turks in 1453 ended the Byzantine Empire and brought Greek-speaking scholars (and substantial Greek manuscripts of patristic and biblical literature) to the West. The invention of the printing press by Gutenberg c. 1455 transformed the conditions for religious communication. The end of the period is conventionally dated to 31 October 1517 — Luther's 95 Theses.
3. Principal figures
Gregory the Great (c. 540 – 604)
Gregory I "the Great" — born to a senatorial Roman family, monastic founder before his papacy, pope from 590 to 604 — is the hinge figure between the patristic and medieval Western Christianity. Substantively a late patristic Latin theologian in the Augustinian tradition, pastorally a medieval church-builder negotiating with the Lombard Germanic kings, ecclesially a developer of the Roman administrative structure that would become the medieval papacy. His principal works include the Pastoral Rule (a major treatise on pastoral ministry that shaped medieval clerical practice for centuries), the Moralia in Job (an extensive allegorical commentary on Job that became the principal medieval moral-theological resource), the Dialogues (a collection of stories about Italian saints), and the substantial homily and letter corpus. His liturgical reform shaped the Western Latin Mass; his missionary work (especially the dispatch of Augustine of Canterbury to convert the Anglo-Saxons in 597) substantially Christianised Northern Europe. The Reformed reader receives Gregory's pastoral and theological work substantively while engaging critically the development of the Roman papacy his pontificate substantially advanced. Gregory the Great page.
Anselm of Canterbury (1033 – 1109)
Anselm — born in northern Italy, abbot of Bec in Normandy, archbishop of Canterbury from 1093 — is the first major Western theologian after Gregory the Great and the founder of medieval scholasticism. His Proslogion (1077) articulates the ontological argument for the existence of God — the argument from the concept of God as "that than which nothing greater can be conceived" to the necessity of God's existence — which has been the subject of substantial subsequent philosophical-theological discussion. His Cur Deus Homo (Why God Became Man, c. 1098) is the foundational medieval treatment of the atonement and the substantive ancestor of the Reformed penal-substitutionary doctrine of the cross. Anselm's careful Christological work, his substantive defence of the Trinitarian doctrine, and his integration of Augustinian theology with the dialectical method that scholasticism would later develop together make him one of the most important Christian theologians between Augustine and Aquinas. The Reformed engagement with Anselm has been substantial across the Reformation and modern Reformed periods (Calvin engages him; modern Reformed evangelical retrieval has been substantial through Carl Trueman, Steven Duby, and others). R. W. Southern's Saint Anselm: A Portrait in a Landscape (Cambridge, 1990) is the standard scholarly biography. Anselm page.
Bernard of Clairvaux (1090 – 1153)
Bernard of Clairvaux — Cistercian monastic founder, abbot of the great monastery he founded at Clairvaux, the most influential ecclesial figure of mid-twelfth-century Europe — is the principal medieval theologian of the warm contemplative-devotional tradition. His Sermons on the Song of Songs (86 sermons, unfinished at his death; substantially preserved) are the principal medieval Christian devotional treatment of union with Christ. His treatise On Loving God articulates the medieval Christian doctrine of love of God in four progressive stages. His engagement with theological controversies (particularly the dispute with Peter Abelard at the Council of Sens in 1140, where Bernard's substantive theological criticisms of Abelard's rationalist tendencies were vindicated) is also substantial. Bernard's work substantially shaped the later Reformation devotional tradition — Luther read Bernard with appreciation; Calvin engages Bernard extensively in the Institutes on the doctrine of grace; the broader Reformed evangelical reception has been warm. The Reformed reader engages Bernard substantively while distinguishing the substantive devotional and theological work from some of the high-medieval Marian and saint devotion that has grown around Bernard's name. Bernard page.
Thomas Aquinas (1225 – 1274)
Aquinas — born in southern Italy, Dominican friar from 1244, student of Albert the Great, university professor at Paris and Naples — is the principal high-medieval theological mind and the author of the Summa Theologiae, the great medieval synthesis of patristic Christian theology with Aristotelian philosophy. The Summa (begun 1265, unfinished at his death in 1274) is in three large parts: on God and creation (Prima Pars); on the moral life and the virtues (Secunda Pars in two parts); on Christ, the sacraments, and the last things (Tertia Pars, unfinished). The substantive theological framework — the doctrine of God; the Christology drawn from Chalcedon; the substantial doctrine of grace inherited from Augustine; the careful treatment of the moral and ethical questions; the substantive engagement with Aristotelian philosophical categories — has shaped Western Christian theology for nearly eight centuries. The Reformed engagement with Aquinas has been complicated: the Reformation contested certain Thomistic conclusions (the medieval Roman sacramental system; the doctrine of merit and the treasury of merit; certain elements of the doctrine of the church); but the substantive theological framework has been the object of substantial recent Reformed retrieval (Steven Duby's God in Himself, IVP Academic, 2019; Matthew Levering's various engagements; Carl Trueman; Michael Allen; and the broader contemporary Reformed-Thomistic conversation). The Reformed reader who reads Aquinas's substantive theology while exercising discernment on the specific Roman developments engages one of the great Christian theological minds. Aquinas page.
Bonaventure (1221 – 1274)
Bonaventure — born in central Italy, Franciscan from 1243, minister general of the Franciscan order from 1257, the principal Franciscan theological mind of the high medieval period — represents the Augustinian-Franciscan theological alternative to the Thomistic-Dominican synthesis. His Itinerarium Mentis in Deum (The Soul's Journey into God, 1259) articulates the Franciscan contemplative theology in compact and beautiful form. His Breviloquium is a more systematic theological work. His engagement with the dispute over the use of Aristotelian philosophy in theology was substantively more cautious than Aquinas's; the long Augustinian-Franciscan and Thomistic-Dominican debate across the rest of the medieval period reflects substantively different visions of Christian theology, both substantively orthodox. The Reformed engagement with Bonaventure has been more limited than with Aquinas, but recent Reformed-Franciscan engagement has begun.
Catherine of Siena (1347 – 1380)
Catherine of Siena — Dominican lay tertiary, mystical writer, political-ecclesial figure who intervened substantively in the late-fourteenth-century papal crises — is one of the principal women theological writers of the medieval period. Her Dialogue (a substantial mystical-theological work; she dictated it during ecstatic experiences in 1377 – 78) and her substantial letter corpus are major late-medieval religious documents. Her role in pressuring Pope Gregory XI to return from Avignon to Rome (he did so in 1377, shortly before his death and the eruption of the Great Western Schism) was substantial. The Reformed reader engages Catherine carefully — the late-medieval mystical-ecstatic tradition is not the Reformed pastoral model — but the substantive Christian witness of her life and the depth of her devotional engagement are part of the genuine medieval Christian heritage.
John Wycliffe (c. 1330 – 1384)
John Wycliffe — Oxford theologian, master of Balliol College, doctor of theology — is the principal late-medieval English reformer and the substantive theological precursor of the Reformation. His substantive theological work pressed substantive concerns: the authority of Scripture above tradition (a substantive precursor of sola Scriptura); the necessity of vernacular Bible translation (the Wycliffe Bible, produced by Wycliffe and his disciples in the 1380s, was the first complete English Bible); the substantive contestation of the developed Roman papal monarchy; substantive contestation of transubstantiation (Wycliffe held a form of "remanence" — the substance of the bread and wine remains after consecration even as Christ is also present); substantive contestation of indulgences, monastic abuses, and clerical corruption. Wycliffe was condemned in his lifetime but died of natural causes; his bones were exhumed and burned posthumously by order of the Council of Constance in 1428. The Lollard movement that followed his teaching in England was suppressed substantially in the early fifteenth century but continued underground until the Reformation. The Reformed evangelical tradition stands in substantive continuity with Wycliffe's pre-Reformation gospel witness. Wycliffe page.
Jan Hus (c. 1369 – 1415)
Jan Hus — Czech theologian, rector of the University of Prague, principal Bohemian reformer — substantially carried Wycliffe's theological convictions into the Bohemian context. His substantive contestation of clerical corruption, the sale of indulgences, the developed Roman papal monarchy, and certain elements of the medieval Roman sacramental system pressed the substantive Reformation concerns nearly a century before Luther. Hus was summoned to the Council of Constance (1414 – 1418) under an imperial safe-conduct, was tried for heresy in defiance of the safe-conduct, and was burned at the stake on 6 July 1415. His martyrdom became one of the great pre-Reformation gospel witnesses; his Bohemian followers (Hussites, divided into moderate Utraquists and radical Taborites) carried his work forward through the fifteenth century, with substantive engagement with the later Bohemian Brethren (Unitas Fratrum) that became part of the Reformation. The Reformed evangelical tradition stands in substantive continuity with the Hussite pre-Reformation gospel witness. Hus page.
Thomas à Kempis (c. 1380 – 1471)
Thomas à Kempis — Augustinian canon at Mount St Agnes near Zwolle in the Netherlands — is most likely the author of The Imitation of Christ (c. 1418 – 1427), the most-read devotional work in the Christian tradition after the Bible. The work is the principal articulation of the devotio moderna — the late-medieval Northern European devotional movement that emphasised practical piety, the imitation of Christ in everyday life, and a substantive personal engagement with the gospel. The Reformed reception of The Imitation of Christ has been substantial — Luther read it with appreciation; Calvin engages it; modern Reformed evangelical devotional life still draws on it — while exercising discernment on certain late-medieval Catholic devotional elements (some of the Marian and Eucharistic-piety material, the more rigorist ascetic instructions). The Reformed reader profits from The Imitation as one of the great medieval devotional works of the church.
4. Doctrinal developments
The developed Roman papal monarchy
The medieval Western church saw the substantial development of the doctrine of papal authority from the patristic Petrine claims (already substantively articulated in Leo the Great) into the fully developed medieval papal monarchy. Key developments: Gregory the Great's substantive consolidation of Roman administrative authority (c. 590 – 604); the Donation of Constantine (an 8th-c. forgery that purported to grant the popes vast secular authority in Italy and the West; eventually exposed as a forgery by Lorenzo Valla in 1440 but substantially relied on through the medieval period); the Pseudo-Isidorian Decretals (mid-9th c., another influential forgery providing patristic warrant for papal claims); the Gregorian Reform of the 11th c. (Gregory VII's Dictatus Papae of 1075 articulating the papal claims with extraordinary force); Innocent III's pontificate (1198 – 1216) bringing the papal monarchy to its high-medieval peak; Boniface VIII's Unam Sanctam (1302) claiming that "it is altogether necessary for salvation for every human creature to be subject to the Roman Pontiff." The Reformed tradition contests this development substantively. See The Reformation and the Leo the Great page.
The seven-sacrament system
The medieval church developed the doctrine of seven sacraments — baptism, confirmation, Eucharist, penance, anointing of the sick, holy orders, marriage — across the high medieval period. Peter Lombard's Sentences (c. 1150) is the document that formally enumerates the seven; the Second Council of Lyon (1274) and the Council of Florence (1439) gave the developed seven-sacrament doctrine formal conciliar definition. The Reformation contested this system substantively: Luther's Babylonian Captivity of the Church (1520) reduces the sacraments to two (baptism and the Lord's Supper), with penance retained as a modified practice; Calvin and the Reformed confessions consolidate the two-sacrament position. The Reformed contestation rests on substantive theological grounds — the requirement of a true sacrament that it be instituted by Christ in the New Testament and combined with a Christ-instituted promise of the gospel — that the medieval seven-sacrament system did not consistently meet.
Transubstantiation
The doctrine of transubstantiation — that in the Eucharistic consecration the substance of the bread and wine is changed into the substance of the body and blood of Christ, with only the "accidents" (appearance, taste, etc.) of the bread and wine remaining — was formally defined at the Fourth Lateran Council in 1215 and substantively articulated by Aquinas in the Summa Theologiae Tertia Pars Question 75. The doctrine drew on substantial patristic Eucharistic theology but pressed it into a particular Aristotelian metaphysical framework (substance vs. accidents) that the patristic tradition had not used. The Reformation contested transubstantiation substantively: Luther argued for "sacramental union" or "consubstantiation" (the body and blood are truly present "in, with, and under" the bread and wine, without the substance of the bread and wine being changed); Zwingli pressed a more memorialist position; Calvin articulated the spiritual real presence (the believer truly feeds on the body and blood of Christ by the Holy Spirit, with Christ's bodily presence at the right hand of the Father). The Reformed conviction is the Calvinian articulation; the contest with transubstantiation has been continuous since 1517. See Calvin.
The doctrine of merit and the treasury of merit
The medieval Roman church developed a substantive doctrine of merit — that good works performed in a state of grace genuinely merit further grace from God (in a "congruous" sense in the early medieval period; in a "condign" sense pressed harder in the high and late medieval period). The related doctrine of the treasury of merit (the surplus merit of Christ and the saints, available for distribution by the church through indulgences) was developed in the 12th and 13th centuries and formalised by Pope Clement VI's bull Unigenitus (1343). The doctrine of indulgences — the remission of temporal penalty for sin, drawn from the treasury of merit, available through specified penitential acts or (notoriously by Luther's time) monetary payments — grew on this foundation. The 1517 controversy that produced Luther's 95 Theses turned on the practical abuse of indulgences (the Tetzel campaign financing St Peter's basilica); the substantive Reformed contestation runs deeper — to the doctrine of merit itself. The Reformation conviction of justification by faith alone on the ground of Christ's righteousness imputed to the believer (not the believer's meritorious works) substantively contests the medieval merit system. See Luther and Soteriology.
The developed Marian devotion
The medieval church developed substantive Marian devotion across the period — the doctrine of Mary's perpetual virginity (substantively patristic); the doctrine of the Assumption (formally defined only in 1950 but substantively medieval); the doctrine of the Immaculate Conception (formally defined only in 1854 but substantively in medieval circulation from the 11th c. through the work of Anselm's nephew Eadmer and others, against opposition from Aquinas himself who held that Mary was sanctified after conception rather than at it); the doctrine of Mary as Mediatrix (substantively medieval and pressed substantially in late-medieval devotion); the rosary (popularised in the late medieval period). The substantive doctrinal accumulation around Mary developed beyond apostolic warrant. The Reformation contested these developments substantively: Mary is honoured as the mother of the incarnate Lord (in the strict Cyrilline-Chalcedonian theotokos sense) but is not the object of worship, prayer, or saving mediation; Christ alone is the Mediator (1 Tim 2:5). See the Cyril of Alexandria page on the proper Christological theotokos doctrine.
Purgatory and the developed afterlife doctrine
The medieval church developed substantive doctrine of purgatory — the intermediate state in which the souls of the faithful who died in a state of grace but who still bore temporal penalty for sin are purified before entering heaven. The doctrine was substantively articulated by Gregory the Great (c. 600); developed substantially in the 12th c. through Hugh of St Victor and Peter Lombard; formalised at the Second Council of Lyon (1274) and the Council of Florence (1439). The doctrine of indulgences for the dead (the use of indulgences to shorten purgatorial suffering for departed souls) grew on this foundation and was a substantive element of the 1517 controversy. The Reformation contested purgatory substantively: the doctrine lacks clear biblical warrant; the gospel of justification by faith alone leaves no temporal penalty for sin requiring purgatorial purification (Christ's perfect satisfaction is complete); the practice of indulgences for the dead was a substantive financial-and-pastoral abuse. The Reformed conviction is that believers at death are immediately in conscious presence with the Lord (Westminster Confession 32; 2 Cor 5:8; Phil 1:23), without intermediate purification. See Systematic Theology.
The substantive scholastic theological achievement
Alongside the doctrinal developments the Reformation contested, the medieval scholastic tradition produced substantive theological work the Reformation received and that contemporary Reformed evangelical theology has been recovering: Anselm's atonement theology (the substantive ancestor of Reformed penal substitution); Aquinas's doctrine of God (the substantive foundation of classical Christian theism that Steven Duby and others have been retrieving for contemporary Reformed theology); Aquinas's Christology (substantively Chalcedonian and substantively useful for Reformed Christology); Aquinas's substantial doctrine of grace (Augustinian in foundation, with substantive elements the Reformed tradition can affirm); the substantive engagement with Aristotelian philosophy that gave Western Christian theology much of its conceptual vocabulary. The Reformed evangelical retrieval of medieval theology in writers like Steven Duby, Matthew Levering's engagement with Reformed theology, Carl Trueman, Michael Allen, and others has been one of the bright spots of recent Reformed theological work. See Systematic Theology.
5. Worship, piety, and church order
Monasticism — Benedictine, Cistercian, Carthusian, Mendicant
Monasticism was the principal medieval institution of intensive Christian formation. The Benedictine Rule (c. 540, by Benedict of Nursia) was the foundational monastic document of the Latin West; Cluniac reform from the 10th c. and Cistercian reform from the 12th c. (Bernard of Clairvaux's order) renewed Benedictine monasticism repeatedly; the Carthusians (from 1084) developed a more eremitic monastic life; the Mendicant orders of the 13th c. (Franciscans 1209, Dominicans 1216, Carmelites and Augustinian Hermits later) developed urban mendicant ministry. Monasteries were the principal sites of medieval education, manuscript copying (preserving classical and patristic literature), agricultural and economic development, and intensive spiritual formation. The Reformed contestation of monasticism (the Reformation closed monasteries across Protestant territories) rested on substantive theological grounds — the rejection of the medieval distinction between "spiritual" estates (monastic) and "secular" callings as lesser; the rejection of monastic vows as binding above ordinary Christian vocation; the rejection of celibacy as a higher Christian state — while recognising the substantial historical contributions of medieval monasticism to the preservation and transmission of Christian culture. The Reformed conviction of vocation in ordinary Christian work (Calvin's doctrine; Luther's substantial recovery) is the alternative to the medieval monastic-secular distinction.
The medieval liturgy — Western Latin and Byzantine
The medieval Western liturgy — the Latin Mass, the daily Office (Lauds, Prime, Terce, Sext, None, Vespers, Compline, Matins), the liturgical year — substantially developed across the medieval period from its late-patristic foundations into the rich liturgical tradition that the Reformation inherited and substantially reformed. The Byzantine East developed its own liturgical tradition (the Divine Liturgy of St John Chrysostom, the various Eastern offices, the iconographic-liturgical engagement that the iconoclastic controversies of the 8th–9th c. eventually settled). The Reformed worship reform substantially simplified the Western Latin Mass — removing the doctrine of the Mass as sacrifice, the Latin language, much of the medieval ceremonial — while retaining the substantive elements (the call to worship, the prayer of confession, the reading and preaching of the Word, the sacraments, prayer, congregational singing). The medieval liturgical inheritance remains substantively present in the Anglican-Reformed and broader Reformed liturgical traditions.
The medieval mystical tradition
The medieval period produced a substantial mystical tradition — Bernard of Clairvaux on the Song of Songs, the Victorines (Hugh and Richard of St Victor), Bonaventure's Itinerarium, the Rhineland mystics (Meister Eckhart, John Tauler, Henry Suso), the English mystics (Richard Rolle, Walter Hilton, Julian of Norwich, the Cloud of Unknowing anonymous, Margery Kempe), the late-medieval devotio moderna (Thomas à Kempis's Imitation of Christ, Geert Groote). The tradition is substantively varied — some figures are substantively orthodox and substantively useful for Reformed devotional life (Bernard, à Kempis, Julian of Norwich's careful Trinitarian devotion); others (especially some of the more speculative Eckhartian and late-medieval mystical traditions) press in directions Reformed theology contests. The careful Reformed engagement reads the medieval mystical tradition selectively. See Systematic Theology.
Parish life and popular piety
The substantive Christian life of the medieval period was lived primarily in the parishes — the local church communities under the ministry of secular clergy (priests, deacons, etc.) administering the sacraments and providing pastoral ministry to the laity. Eamon Duffy's The Stripping of the Altars (Yale, 1992) is the major recent scholarly account of substantive English parish life in the late medieval period and is a substantive corrective to older Protestant readings that presented medieval lay Christianity as wholly corrupt or superstitious. The reality was substantive Christian piety — daily prayer, Sunday Mass attendance, household devotion, careful preparation for death, substantial almsgiving, pilgrimage — combined with substantive doctrinal errors and substantial uneven pastoral quality. The Reformed engagement is grateful for the substantive piety and clear-eyed about the doctrinal errors and the structural pastoral problems.
The medieval art and architecture
The medieval period produced one of the great artistic and architectural achievements of human history. Romanesque architecture (c. 1000 – 1200), Gothic architecture (c. 1140 – 1500), the great medieval cathedrals (Chartres, Notre-Dame de Paris, Reims, Cologne, Canterbury, Salisbury, Cologne), the development of stained-glass art, the Romanesque and Gothic sculptural tradition, the medieval illuminated manuscript tradition, the development of polyphonic sacred music (Notre-Dame school, Machaut, the ars subtilior, the Burgundian and Franco-Flemish polyphonists running into Josquin des Prez), the medieval iconographic tradition of the East — all this is substantive Christian artistic and cultural achievement. The Reformation's contested engagement with religious art (the radical Reformation's iconoclasm; the more moderate Reformed contestation of images that the Reformation associated with idolatry; the Lutheran retention of much religious art) is a complicated story; the substantive medieval artistic inheritance has been received variously across the Reformed traditions.
6. Controversies of the era
The Iconoclastic Controversies (726 – 843)
The Byzantine iconoclastic controversies of the 8th and 9th centuries were the principal Eastern Christian theological controversy of the early medieval period. Emperor Leo III (reigned 717 – 741) initiated the first phase of iconoclasm in 726, on the grounds that the veneration of icons violated the second commandment and contributed to the Christian losses to Islam (the iconoclastic emperor read the rise of Islam as divine judgement on Christian idolatry). The iconodule defence — articulated principally by John of Damascus (c. 675 – 749, working in Muslim-ruled territory outside the iconoclastic emperor's reach) and by Theodore the Studite (759 – 826) — argued that the veneration of icons is theologically grounded in the incarnation (the eternal Word became visible flesh, making material representation of Christ both possible and appropriate) and is to be distinguished from worship (proper only to God). The Seventh Ecumenical Council at Nicaea II (787) formally affirmed the iconodule position; iconoclasm revived under Leo V (813 – 820) and continued until 843, when the empress Theodora finally restored icons (the "Triumph of Orthodoxy" still celebrated on the first Sunday of Lent in the Eastern Orthodox liturgical calendar). The Reformed reception of Nicaea II is selective — most Reformed bodies do not formally receive the Seventh Council as ecumenical, holding (substantively) that the iconoclastic theological concern about the second commandment is more substantive than the Council's iconodule conclusions allow — while the broader Reformed engagement with religious imagery is varied across the tradition. See The Ecumenical Councils.
The Great Schism (1054)
The Great Schism of 1054 is conventionally dated to the mutual excommunications between Cardinal Humbert (papal legate at Constantinople) and Patriarch Michael Cerularius on 16 July 1054. The substantive issues that produced the schism had been developing for centuries: the filioque clause (the Western addition of "and from the Son" to the Nicene Creed's clause on the Spirit's procession from the Father); the question of papal primacy (Roman claims to universal jurisdiction vs. Eastern Orthodox conciliar ecclesiology); various liturgical and canonical differences (Western use of unleavened bread in the Eucharist; clerical celibacy in the West vs. married clergy in the East; differences over Saturday fasting and other practices). The 1204 sack of Constantinople by the Fourth Crusade made substantive reconciliation impossible; the 1439 Council of Florence achieved a temporary union that was rejected by the Eastern Orthodox communities after the council; the fall of Constantinople in 1453 ended the political pressure for union. The modern Catholic-Orthodox engagement has substantially advanced since the mutual lifting of the 1054 excommunications by Pope Paul VI and Patriarch Athenagoras in 1965, but the substantive theological and ecclesiological issues remain. The Reformed engagement with the Schism is detached from formal commitment to either side; the substantive Reformed contestation of medieval Roman primacy claims and of certain Eastern Orthodox sacramental theology distinguishes the Reformed tradition from both. See Leo the Great.
The Crusades (1095 – 1291 and continuing)
The Crusades were a series of substantive military expeditions, called by the medieval popes, primarily to recover the Christian Holy Land from Muslim rule. The First Crusade (1095 – 1099, called by Pope Urban II at the Council of Clermont) captured Jerusalem in 1099 amid substantial massacre of Muslim and Jewish inhabitants. The subsequent crusades met with varying military success and gradually receding territorial holdings; the Fourth Crusade (1202 – 1204) catastrophically sacked Constantinople (a Christian city) on the way to the Holy Land, deepening the Catholic-Orthodox schism; the last Crusader stronghold (Acre) fell in 1291. The "crusading" framework continued to be applied across the medieval period to various Christian military enterprises (against the Albigensians in southern France, the Baltic Crusades against pagan Slavs, the Reconquista in Spain). The Reformed reading of the Crusades is substantively critical: the substantive theological warrant for armed Christian invasion of foreign territories on religious grounds is weak; the substantive moral failures of the Crusades (the Jerusalem massacre, the sack of Constantinople, the various atrocities) cannot be softened; the substantive religious-and-political confusion of medieval Crusading is a substantial element of the Reformation's contestation of the medieval Roman Catholic developed system. The Reformed engagement with Christian-Muslim relations stands in a different framework — the proclamation of the gospel rather than the conquest of territory.
The conciliarist movement (1378 – 1449)
The Great Western Schism (1378 – 1417) produced substantive theological and ecclesiological pressure for a council to resolve the rival papal claims. The Council of Pisa (1409) attempted to depose both then-claiming popes and elect a third, but only succeeded in producing a third papal claimant. The Council of Constance (1414 – 1418) successfully resolved the schism (deposing two popes, accepting the resignation of a third, and electing Martin V in 1417) and condemned Wycliffe and Hus. The Council of Basel (1431 – 1449) pressed the conciliarist case — that general councils hold authority above the papacy — substantively further; eventually the council was substantially defeated by the restored papacy under Eugenius IV. The substantive theological question — does a general council hold authority above the papacy, or does the pope hold authority above the council? — was settled formally in favour of papal supremacy at the First Vatican Council in 1869 – 1870. The conciliarist movement is one of the substantial late-medieval contestations of the developed papal monarchy and is a substantive precursor of the Reformation's contestation. The Reformed reader engages this movement with substantial historical interest. See The Reformation.
The pre-Reformation movements — Waldensians, Lollards, Hussites
The pre-Reformation movements — the Waldensians (from c. 1170, founded by Peter Waldo of Lyon), the Lollards (followers of Wycliffe in 14th- and 15th-c. England), and the Hussites (followers of Hus in 15th-c. Bohemia) — pressed substantive Reformation concerns nearly a century or more before Luther: the substantive authority of Scripture; the necessity of vernacular Bible; the rejection of indulgences; the contestation of clerical corruption; the rejection of certain elements of the developed Roman sacramental system. The substantive cost of these movements was severe — the Waldensians were persecuted across centuries (and still exist as a small Italian Protestant community); the Lollards were suppressed substantively in the 15th c. but continued underground and provided some of the readiest reception of Reformation ideas in 16th-c. England; the Hussites were partially suppressed but produced the substantive Bohemian Brethren (Unitas Fratrum) that became part of the Reformation. The Reformed evangelical tradition stands in substantive continuity with these pre-Reformation gospel witnesses.
7. The theological stakes for the contemporary Reformed reader
The continuity of the catholic apostolic tradition through the medieval church
The Reformed conviction that the Reformation was a recovery of catholic apostolic Christianity (not the invention of a new religion) depends substantively on recognising the continuity of the apostolic tradition through the medieval church. The canon of Scripture, the ecumenical creeds (Apostles', Nicene, Athanasian, Chalcedonian), the substantive Trinitarian and Christological theology, and the substantial doctrine of grace were preserved and transmitted through the medieval period. The Reformed engagement with the medieval church is therefore grateful at this level: without the medieval preservation, the Reformation's recovery would not have been possible. See Creeds and Confessions.
The doctrine of grace through Augustine to Anselm to the Reformation
The substantive Augustinian doctrine of grace was preserved and developed through the medieval theological tradition. Anselm's Cur Deus Homo articulates the substantive Latin atonement theology that the Reformed penal-substitutionary doctrine builds on. Aquinas's substantial doctrine of grace, while pressed in some particular directions the Reformation contested, is substantively Augustinian. The substantive Reformed doctrine of grace (recovered against late-medieval semi-Pelagian drift) stands in continuity with the patristic-medieval Augustinian inheritance. See Augustine and Pelagianism.
The substantive doctrine of God and classical Christian theism
The medieval scholastic tradition (Anselm, Aquinas, and others) preserved and developed the substantive doctrine of God — the classical Christian theism articulating divine simplicity, eternity, immutability, impassibility, omnipotence, omniscience, goodness — that the Reformed dogmatic tradition substantially received. The contemporary Reformed evangelical retrieval of classical theism in writers like Steven Duby (God in Himself, IVP Academic, 2019; Divine Simplicity, T&T Clark, 2016), James Dolezal, Matthew Barrett, and others draws substantially on the medieval-scholastic inheritance. See Systematic Theology.
Christology and the Chalcedonian inheritance
The medieval Christological tradition substantively received and transmitted the Chalcedonian Christology that the Reformation explicitly received. The Reformed Christology in the Reformed confessions stands in this Chalcedonian-medieval-Reformation line. See Chalcedon and Christology.
The pre-Reformation gospel witness
The Waldensians, Lollards, Hussites, and other pre-Reformation movements pressed substantive Reformation concerns and substantively suffered for their gospel witness. The Reformed conviction that the gospel was preserved in the medieval church (even where the institutional church had accumulated substantive error) stands substantively on this pre-Reformation gospel witness. See The Reformation.
The substantive doctrinal accretions and the Reformation contestation
The substantive doctrinal accretions of the medieval period — the developed papal monarchy, transubstantiation, the seven-sacrament system, the doctrine of merit and indulgences, the developed Marian and saint devotion, purgatory — are the substantive elements of the medieval Roman Catholic system the Reformation contested. The Reformed engagement is clear-eyed: these are not minor adjustments; they are substantive theological developments that the Reformation had to address. The continued Reformed-Catholic engagement (Trent's response to the Reformation, the modern Catholic-Reformed dialogues, the contemporary Reformed engagement with Catholic theology) returns to these substantive points. See The Reformation.
8. The hard places — read honestly
The persecution of religious dissent
The medieval Roman Catholic church substantively persecuted religious dissent across the period. The Albigensian Crusade (1209 – 1229) substantially destroyed the Cathar movement in southern France with massive loss of life. The medieval Inquisitions (the episcopal Inquisitions from the 12th c., the papal Inquisition from 1231, the Spanish Inquisition from 1478) used civil and ecclesial coercion to suppress theological dissent across the medieval and early modern periods. The persecution of the Waldensians across centuries, the suppression of the Lollards in 15th-c. England, the burning of Hus at the Council of Constance (1415) — all are substantive moral failures of the medieval church that the Reformed reader names without softening. The modern Reformed engagement with religious liberty (the long Reformed political-theological tradition from the 17th-c. English Baptists onward) substantively contests the medieval Catholic (and the early Reformation Protestant) acceptance of civil coercion of religious dissent.
The Crusades and the violent religious expansion
The Crusades — the substantive military expeditions called by the medieval popes — are substantive moral failures of the medieval church that the Reformed reader names honestly. The Jerusalem massacre of 1099, the Constantinople sack of 1204, the Baltic Crusades against pagan Slavs, the Reconquista in Spain (which extended into the early Reformation period and included the substantial mistreatment of Jewish and Muslim populations under Christian rule) — all are substantive failures of Christian witness. The Reformed engagement with Christian-Muslim and Christian-Jewish relations stands substantively away from this medieval framework.
The persecution of European Jewry
The medieval period saw substantial persecution of the European Jewish population — the First Crusade's pogroms against Rhineland Jewish communities in 1096; the expulsions of Jews from England (1290), France (multiple expulsions from the 12th to 14th c.), and Spain (1492); the various blood-libel accusations and host-desecration accusations across the period; the substantive religious-economic persecution that became one of the dark continuities of European medieval-and-modern history. The medieval theological foundations for this persecution — substantive supersessionist readings of the relation of the church to Israel; the "perfidious Jews" prayer in the medieval Good Friday liturgy; the substantive medieval theological literature against Jewish religion — produced grievous moral and pastoral consequences. The Reformed engagement with the Christian-Jewish question is substantively informed by Romans 9–11 and by the Reformed engagement with the unity of the covenants; the medieval foundation has to be named honestly and contested. See OT Theology.
The doctrinal accretions and the gospel
The substantive doctrinal accretions of the medieval period — the doctrine of merit, the developed sacramental system, the developed papal claims, the developed Marian and saint devotion — were not minor cosmetic adjustments. They were substantive distortions of the gospel of grace that the Reformation had to address. The Reformed reader does not soften this. The Reformation contestation of the medieval Roman Catholic developed system was substantive theological work, not cosmetic adjustment. The substantive distance between the Reformed and Roman Catholic positions on the gospel of grace — substantively the same distance the Reformation addressed in 1517 — remains real. See The Reformation.
The institutional corruption
The substantive institutional corruption of the late-medieval church — the absentee bishops, the simony (sale of church offices), the clerical concubinage, the sale of indulgences, the pluralism (one cleric holding multiple offices), the Avignon Papacy's financial-administrative excesses, the Renaissance Papacy's substantive secular politics under popes like Alexander VI Borgia (1492 – 1503) and Julius II (1503 – 1513) — was substantive. The Reformation reformers were not exaggerating when they spoke of the need for substantive ecclesial reform; the pre-Reformation movements (Wycliffe, Hus) had also spoken substantively about this corruption decades and centuries earlier. The Reformed engagement names the institutional corruption honestly while recognising that substantive Christian ministry continued at the parish level across the period.
The treatment of women within the medieval church
The medieval church's treatment of women was substantively varied. On one hand, substantial women theological and spiritual writers (Hildegard of Bingen, Bridget of Sweden, Catherine of Siena, Julian of Norwich, Teresa of Ávila slightly later) had substantive theological and pastoral ministry; medieval monasticism provided some women with substantial intellectual and pastoral opportunity outside the household; substantial women mystics shaped medieval devotional life. On the other hand, women were systematically excluded from ordained ministry; substantive medieval theological work on women drew on inherited misogynistic patterns (some of it patristic in origin); the witch trials began in the late medieval period (substantially in the 15th c.) and would expand catastrophically in the early modern period. The Reformed engagement reads this substantively varied history honestly; the modern Reformed engagement with the place of women in the church draws on multiple substantive concerns the Reformed tradition has continued to work through.
The Eastern Orthodox-Roman Catholic-Reformed substantive divergences
The medieval period saw the substantial development of the three principal lines of Christianity that the Reformation eventually addressed: the Roman Catholic Western tradition (with the developed papal monarchy, the seven-sacrament system, the developed Marian devotion); the Eastern Orthodox tradition (with its distinctive iconographic-liturgical-monastic tradition, its conciliar ecclesiology, its hesychast contemplative tradition); and the Reformation tradition the Reformed reader inherits. The substantive theological divergences among these three traditions are real and substantive; the Reformed reader engages each substantively without committing to either Catholic or Orthodox patterns. The contemporary ecumenical engagement among the three traditions (the modern Catholic-Reformed dialogues, the Reformed-Orthodox conversations, the long historical engagement) is the current setting of the Reformed engagement.
9. Influence on later Christianity
The Reformation as recovery and contestation
The Reformation stands substantively in continuity with the substantive medieval inheritance (the canon, the creeds, the patristic theology, the substantive doctrine of grace through Anselm and Aquinas) and in contestation of the medieval accretions (the papal monarchy, transubstantiation, the seven-sacrament system, the doctrine of merit, the developed Marian devotion). The Reformation is therefore not the rejection of medieval Christianity but the selective recovery and substantive reform of the catholic Christian inheritance. See The Reformation.
The substantive doctrinal inheritance through Anselm and Aquinas
The Reformed dogmatic tradition has substantially received the substantive medieval theological inheritance through Anselm (the atonement theology that prepared the Reformed penal-substitutionary doctrine) and Aquinas (the substantive doctrine of God, the substantive Christology, the substantial doctrine of grace). The contemporary Reformed retrieval of medieval theology in writers like Steven Duby, James Dolezal, Matthew Barrett, Carl Trueman, and others has been one of the bright spots of recent Reformed evangelical work.
The institutional, devotional, and artistic inheritance
The medieval period bequeathed to subsequent Christianity the substantive institutional development of parish life, the substantial monastic-mystical-devotional tradition, the artistic-architectural-musical heritage of Western Christian civilisation. The Reformed engagement with this inheritance has been varied: the Reformation reformed monastic life, contested certain medieval art forms, simplified the liturgical inheritance, while substantially preserving much of the substantive Christian devotional heritage.
The pre-Reformation gospel witness
The Waldensians, Lollards, Hussites, and other pre-Reformation movements provided the substantive gospel witness within the medieval church that the Reformation consolidated. The Reformed evangelical tradition stands in substantive continuity with this pre-Reformation gospel witness.
The substantive Christian-Muslim and Christian-Jewish patterns
The medieval substantive engagement with Islam and with European Jewry — including the substantial failures — has continued to shape Christian engagement with these communities into the modern period. The contemporary Reformed engagement is substantively different (the rejection of crusading frameworks, the recovery of Romans 9–11 readings of the church-Israel relation, the substantive engagement with Muslim communities through gospel proclamation rather than military or coercive means) but works within the long historical inheritance.
The Eastern Orthodox living tradition
The Eastern Orthodox tradition that emerged from the medieval Byzantine and Slavic Christian world continues to the present as a substantial form of Christianity with substantial differences from both Roman Catholic and Reformation Protestant traditions. The Reformed engagement with Eastern Orthodoxy in the modern ecumenical conversation works substantively within the medieval Eastern Christian inheritance.
10. Modern parallels and lessons
"Dark Ages" caricature — old and new versions
The cruder Protestant historiographical tradition has sometimes presented the medieval period as nine centuries of spiritual darkness from which the Reformation rescued the church. This caricature is unfaithful to the historical record and has been substantially corrected by modern scholarship across the past century. Modern secular versions of the "Dark Ages" narrative (treating the medieval period as a period of substantive cultural and intellectual regression between classical antiquity and modern enlightenment) are equally unfaithful to the historical record. The careful Reformed engagement with the medieval period reads the substantive Christian achievements and the substantive failures together.
The romantic medievalism of contemporary Catholic and Anglo-Catholic apologetics
The opposite caricature — the romantic presentation of the medieval period as the high-water mark of Christian civilisation, with substantive theological-political-cultural integration that contemporary Christianity should attempt to recover — circulates substantively in some contemporary Catholic and Anglo-Catholic apologetic writing (Joseph Pearce, Anthony Esolen, some neo-traditionalist Catholic literature; the Anglican "post-liberal" Radical Orthodoxy movement). The careful Reformed engagement appreciates the substantive theological and cultural achievements of the medieval period while not committing to the romantic medievalist programme; the medieval period also had the developed papal monarchy, transubstantiation, the doctrine of merit, the developed Marian devotion, the substantive persecution of religious dissent, the Crusades, the persecution of European Jewry — all of which the contemporary Reformed reader does not endorse.
The recovery of Christian classical theism
The substantive contemporary Reformed evangelical recovery of classical Christian theism — Steven Duby's God in Himself and Divine Simplicity, James Dolezal's All That Is in God, Matthew Barrett's None Greater, the broader Reformed-classical-theistic conversation — draws substantively on the medieval-scholastic doctrine of God. The Reformed reader engaging this contemporary recovery profits from the substantial Reformed-medieval engagement. See Systematic Theology.
The Reformed engagement with Aquinas
The substantial Reformed engagement with Thomas Aquinas in the past two decades — Carl Trueman, Steven Duby, Matthew Levering's substantial Reformed-Thomistic conversation, the broader engagement — has substantially modified the older Reformation polemic against Aquinas (which had sometimes treated him as the principal source of medieval Roman theological errors). The careful Reformed engagement reads Aquinas substantively: the substantive theological framework can be received gratefully; the specific Roman developments (the sacramental theology, the merit doctrine, certain elements of the doctrine of the church) are engaged critically.
The substantive evangelical engagement with medieval mystics
The contemporary Reformed evangelical engagement with selected medieval mystics — Bernard of Clairvaux's careful Christological-devotional writing, à Kempis's Imitation of Christ, Julian of Norwich's Trinitarian piety — has substantially recovered substantial medieval devotional resources for contemporary Reformed pastoral life. The careful engagement reads selectively, exercising discernment on the substantive Marian and saint-devotion material while receiving the substantive Christ-centred devotional substance.
The pre-Reformation movements and contemporary Christian witness
The substantive courage and gospel witness of the Waldensians, Lollards, and Hussites — substantively contesting clerical corruption, indulgences, and the developed Roman system at substantial personal cost — remains a substantive model for contemporary Christian witness in contested religious-cultural settings. The Reformed reader engaging contemporary cultural pressure on Christian conviction profits from the pre-Reformation example.
The substantive ongoing Catholic-Reformed engagement
The substantive medieval-Reformation theological divergences continue to structure the substantive contemporary Catholic-Reformed engagement. The substantive Reformed contestation of the developed papal monarchy, transubstantiation, the seven-sacrament system, the doctrine of merit, and the developed Marian devotion — all medieval developments substantively contested at the Reformation — remains substantively the same. The substantive modern ecumenical engagement (the various Catholic-Reformed dialogues; the Lutheran-Catholic Joint Declaration on the Doctrine of Justification, 1999, which the Reformed tradition has engaged variously) works within this substantive medieval-Reformation inheritance. See The Reformation.
11. Where to start reading the medieval church
A four-step reading path for beginners
- Start with Bruce Shelley, Church History in Plain Language (5th ed., Nelson, 2020), the medieval chapters. The standard accessible Reformed-evangelical introduction. Read also Justo González, The Story of Christianity, vol. 1 (HarperOne, 2nd ed. 2010).
- Then R. W. Southern, Western Society and the Church in the Middle Ages (Penguin, 1970). The classic accessible scholarly account of medieval Western Christianity; substantively rewarding.
- Then selected primary sources: Anselm's Cur Deus Homo (in any standard edition); Aquinas's Summa Theologiae selections (a Reformed-friendly anthology like The Pocket Aquinas, ed. Vernon J. Bourke, Pocket Library, 1960, is a good starting point); Bernard of Clairvaux's On Loving God; Thomas à Kempis, The Imitation of Christ.
- Then Steven Ozment, The Age of Reform 1250 – 1550 (Yale, 1980). The standard scholarly treatment of the late medieval and Reformation periods; substantively rewards careful reading.
Going deeper — works a Reformed reader will find helpful
- R. W. Southern, Western Society and the Church in the Middle Ages (Penguin, 1970); The Making of the Middle Ages (Yale, 1953); Saint Anselm: A Portrait in a Landscape (Cambridge, 1990).
- Peter Brown, The Rise of Western Christendom (3rd ed., Wiley-Blackwell, 2013).
- Diarmaid MacCulloch, Christianity: The First Three Thousand Years (Penguin, 2009).
- Steven Ozment, The Age of Reform 1250–1550 (Yale, 1980).
- Eamon Duffy, The Stripping of the Altars: Traditional Religion in England 1400–1580 (Yale, 1992); Saints and Sinners: A History of the Popes (Yale, 4th ed. 2014).
- Norman Tanner, The Church in the Later Middle Ages (I.B. Tauris, 2008).
- G. R. Evans, The Medieval Theologians (Wiley-Blackwell, 2001); Anselm (Continuum, 1989).
- Heiko A. Oberman, The Harvest of Medieval Theology: Gabriel Biel and Late Medieval Nominalism (Harvard, 1963; rev. ed. 2000); Forerunners of the Reformation (Holt, 1966).
- John Meyendorff, Byzantine Theology (Fordham, 2nd ed. 1979); Andrew Louth, Greek East and Latin West (St Vladimir's Seminary Press, 2007).
- Nick Needham, 2000 Years of Christ's Power, vols. 2–3 (Christian Focus / Grace Publications, rev. ed. 2016 – 2019). The Reformed-evangelical accessible treatment of the medieval period.
- Steven J. Duby, God in Himself: Scripture, Metaphysics, and the Task of Christian Theology (IVP Academic, 2019); Divine Simplicity (T&T Clark, 2016). The contemporary Reformed retrieval of medieval-scholastic theology.
- James E. Dolezal, All That Is in God (Reformation Heritage, 2017).
- Matthew Barrett, None Greater: The Undomesticated Attributes of God (Baker, 2019).
- Carl R. Trueman's various essays and the Reformed-Thomistic engagement.
- Primary sources: Anselm, Major Works (Oxford World's Classics); Aquinas, Summa Theologiae, selected volumes from the Cambridge edition or the Blackfriars edition; Bernard of Clairvaux, the Cistercian Fathers Series translations; Thomas à Kempis, The Imitation of Christ, various modern translations; Julian of Norwich, Revelations of Divine Love; the Cloud of Unknowing anonymous; selected medieval mystics in Penguin Classics and the Classics of Western Spirituality series.
12. Conclusion: the long medieval continuity, with substantial gratitude and substantive discernment
The medieval period — the nine centuries between Gregory the Great and Luther — is the longest single period in Christian history and one of the most contested in Protestant memory. The substantive achievements of the medieval church are substantial: the preservation of the canon of Scripture, the ecumenical creeds, and the substantive patristic theological tradition; the substantial Christianisation of Northern Europe; the great scholastic theological syntheses (Anselm, Aquinas, Bonaventure); the substantial monastic-mystical-devotional tradition; the artistic-architectural-musical heritage of Western Christian civilisation; the substantial pre-Reformation gospel witness in the Waldensians, Wycliffe and the Lollards, Hus and the Hussites. The substantive accretions and failures of the medieval church are also substantial: the developed Roman papal monarchy; transubstantiation and the seven-sacrament system; the doctrine of merit and the indulgences industry; the developed Marian and saint devotion; the substantive persecution of religious dissent through inquisitions and crusades; the substantial mistreatment of European Jewry; the institutional corruption of the late-medieval church. Both judgements have to be held together; the medieval church is neither the wholesale darkness of cruder Protestant memory nor the unalloyed flowering of cruder Catholic apologetic.
The Reformed posture toward the medieval period is grateful, careful, and substantively engaged. Grateful, because the substantive achievements are real and substantial: the Reformation could not have happened without the medieval preservation of the canon, the creeds, the substantive patristic theological inheritance, and the substantive doctrine of grace through Augustine and Anselm. Careful, because the substantive accretions and failures must be named honestly and the Reformation contestation must not be softened. Substantively engaged, because the contemporary Reformed retrieval of medieval theology — particularly Anselm, Aquinas, Bernard, and the broader medieval theological tradition — has been one of the bright spots of recent Reformed evangelical work, and the Reformed engagement with the substantive Catholic-Orthodox-Protestant theological-ecclesial divergences continues to work within the substantive medieval-Reformation inheritance. The canon, the creeds, the catholic theological tradition, the gospel of grace preserved through nine centuries — the medieval inheritance the Reformed church received and the Reformed reader continues to engage. The papal monarchy, transubstantiation, the merit-and-indulgences system, the developed Marian devotion, the persecution of dissent — the substantive accretions the Reformation contested and the Reformed reader continues to engage as well. Both the gratitude and the contestation are necessary.