In the annals of medieval theology, the name of Berengar (sometimes known as Berengarius) holds a very important place. A monk of Tours and celebrated teacher, Berengar's famous denial use of a substantial change in the Eucharistic elements caused a rift in the 11th century Church that would lead to thirty years of controversy and culminate in massive developments in sacramental theology of the kind not seen since the patristic period. The Berengar controversy looks back and forward; on the one hand, the response of the Church of his day to his heresy shows shows clearly that the Church always understood Christ to be truly present in the sacrament of the Eucharist; on the other hand, the questions and problems posed by Berengar led to many important developments in theology, especially adoption of the term "Transubstantiation" to describe the change in the elements.
History of Berengar
Berengar was born sometime around 999 in the city of Tours; it is unknown whether his origins were humble or noble. Tours had been a very important ecclesiastical center ever since it was graced by the presence of St. Martin in the 4th century and Gregory of Tours in the 6th. During the time of Charlemagne it became the center of the Carolingian Renaissance due to the famous monk-scribe Alcuin, who was Abbot of Marmoutier Abbey in Tours. The city was also the capital of the province of Touraine from the 9th century on, so that by the time Berengar was born, the city of Tours was an important political and ecclesiastical hub, populated by some of the most creative political and religious thinkers of the high middle ages. It was an atmosphere ripe for intellectual inquiry.
Berengar completed primary studies in Tours and then went on to the cathedral school at Chartres where he studied under the famous Fulbert of Chartres. He was distinguished by his quick thought and penetrating intellect, though he does not always seem to have been in agreement with his master Fulbert, who seemed worried by an independent streak that was emerging alongside Berengar's other more admirable qualities.  After his higher education was completed, Berengar took over the famous school of St. Martin at Tours and earned a reputation throughout the Church at large as a gifted teacher and brilliant theologian. He was Archdeacon of Angers in 1037, but was allowed to continue teaching at Tours. Popular, erudite, and demonstrating a penetrating theological insight tempered with a bit of cutting-edge speculation and a disposition towards rationalism, Berengar was the celebrity theologian of the 11th century even as Abelard would be in the 12th. He was the Hans Urs von Balthasar of his day.
But as in the case with Abelard and Balthasar, Berengar's opinions eventually got him into trouble. Prior to the time of Berengar there had been a lively debate going on in the French church over the manner in which Christ was present in the Holy Eucharist. Berengar would ultimately assert that the presence of Christ in the Eucharist was merely spiritual, not physical, a teaching that would erupt into the biggest controversy in the French church of the 11th century.
Before looking at the Eucharistic controversy as it unfolded in the life of Berengar of Tours, we need to look at the context of the controversy.
Background: The Carolingian Eucharistic Controversy
The debate dated back to the mid-9th century and the reign of Charles the Bald, surrounding a book entitled De Corpore et Sanguine Domine written by the learned St. Paschasius Radbertus. St. Paschasius had undertaken to show what was the true doctrine of the Eucharist, drawing on the teaching of the Fathers and the Saints. In his work, Paschasius draws on citations from the saints, especially Ambrose, Augustine and Chrysostom, as well as an exegesis of John 6 and 1 Corinthians 11, and seasons these with accounts of Eucharistic miracles to make his point that in the Eucharist we have nothing other than the real, historic Body of Christ itself, the same Body that was born of the Virgin, suffered on the cross and was resurrected. The book was presented to Emperor Charles the Bald in 844.
Without going into the particular nuances of St. Paschasius' doctrine (in some points he identifies Christ's sacramental presence too closely with His natural body), it suffices to say that the book aroused some opposition in the Church. Charles asked another respected ecclesiastic, Ratramnus of Corbie, to write a rebuttal. Ratramnus insisted that Christ's body was truly present in the Eucharist, but only in a spiritual manner, and as such the Eucharistic body is not the same body as that which was born of Mary, suffered and was Resurrected. Leading ecclesiastics and theologians each took sides; Rabanus Maurus, Walafrid Strabo, Christian Druthmar, and Florus Magister all supported the view of Ratramnus, while the influential Hincmar of Rheims and Haimo of Halberstadt supported St. Paschasius. In general, St. Paschasius seems to have been supported more by the bishops, Ratramnus by the theologians.
The leading supporter of the "spiritual" view of Ratramnus was none other than the eminent theologian and Neoplatonist philosopher John Scotus Eriugena. No doubt influenced by Platonic theories of forms and ideas, Eriugena had supported the notion that what is received at the Eucharist are forms or "figures" of Christ; contemporary Hincmar of Rheims says this assertion was among Eriugena's greatest errors.  Eriugena's support of Ratramnus lent his theory great weight, but St. Paschasius perhaps had even a weightier supporter in Pope Sylvester II (999-1003), who with the Roman Church, believed and taught a miraculous transformation of the elements at the priestly consecration - the pope even wrote a treatise defending the interpretation of St. Paschasius. 
The controversy was never effectively resolved in the 9th century. The Viking invasions of the latter 9th century (Paris was attacked the very year after St. Paschasius presented his treatise to Charles the Bald) and the weakening and subsequent extinction of the Carolingian monarchy brought an end to the scholarly debates among monks that had characterized the Carolingian Renaissance. Though the debate ended, it was never really settled, and French ecclesiastics and theologians continued to maintain their own distinctive opinions on the matter.
Despite the variety of opinions on the matter, it is important to note that the Carolingian Eucharistic controversy was not over whether or not the Church would accept the teaching that Christ is Present in the Eucharist. Both sides, St. Paschasius and Ratramnus and their supporters and detractors, all believed in the "Real Presence" of Christ, but they debated the meaning of the term "real" and in what nature Christ was truly present. St. Paschasius asserted the Body was the true, historic body, and seemed to understand this in a carnal sense; Ratramnus seemed to sense the inherent problem with this and posited a spiritual presence instead, akin to the way that the Holy Spirit is present in a believer's soul but in a superior way. Both sides agreed in a "Real Presence"; neither side taught a communion that was purely symbolic.
Essentially, the Carolingian Eucharistic controversy was the Church's first attempt to work out the distinctions between sacramental form and matter, as well as the more important distinctions between Christ's modes of presence. St. Paschasius knew that the presence of Christ was real in a sense that was more than just a spiritual mode, but Ratramnus rightly suspected that Christ's Real Presence should not be understood in a carnal sense, which seemed to be the extreme that St. Paschasius was leaning towards; this suspicion caused Ratramnus to wrongly deny any change in the elements. What both theologians were looking for was a thoroughly worked out doctrine of a sacramental mode of presence, as opposed to a spiritual or historical.
Four Condemnations of Berengar
It was at the St. Martin School of Tours that Berengar apparently began teaching the doctrine of Ratramnus on a purely spiritual presence without a substantial change in the elements. As the dispute of the 9th century had never been really settled, the teaching of Berengar began attracting attention from other theologians who were troubled by it. This led the teaching of Berengar to be examined by two prelates, Hugues, Bishop of Langres, and Adelman, Bishop of Liège. The two bishops apparently could not come to an agreement on the orthodoxy of Berengar's teaching, which itself is testimony to the imprecise nature of sacramental theology at the time. Adelman appealed to the authority of John Scotus Eriugena in support of Berengar.
But at this point a more eminent ecclesiastic was drawn in to the debate, none other than the famous Lanfranc of Bec, who was at that time Abbot of Bec Monastery . Lanfranc combined saintliness and erudition in a manner that prefigured Aquinas, and his school at Bec was one of the most renowned in Christendom. Lanfranc, hearing Berengar supported by an appeal to Eriugena, condemned Eriugena's opinion as heretical and espoused the doctrine of real change in the elements as put forward by St. Paschasius. The debate of the 9th century was being re-opened.
Around this time (1050), Berengar's teaching apparently was dividing the church regionally and he was called to appear before some local conferences at Brionne and Chartres. The records of these proceedings are lost, but it appears that Berengar appeared in person to defend his doctrine but was unsuccessful. In Easter of 1050, Lanfranc went on a journey to Rome to participate a local council of the Roman Church. This council was not connected with Berengar initially; it had to do with trying charges of simony and other matters connected with the burgeoning Gregorian Reform movement. The Council was extremely well-attended, and with fifty-five bishops and thirty-two abbots in attendance, Lanfranc brought the matter of Berengar to the attention of Pope Leo IX and the Council. Berengar's teaching was soundly condemned by the Council and Pope Leo ordered him to appear before a regional Council at Vercelli the same year.
At this time, for reasons not entirely clear, the French King Henri I denied Berengar permission to attend the Council of Vercelli and had him imprisoned. The Council of Vercelli (convened September, 1050) examined Berengar's doctrine in absentia and condemned it as heresy. At this point Berengar's teaching on the Eucharist had been condemned four times: once at Brionne, once at Chartres, once in Rome and once at Vercelli.
The Decline, Fall and Redemption of Berengar
At the time (1050), Berengar's condemnations did not detract from his broad base of support. One of the most eminent theologians in favor of Berengar's teaching was Eusebius Bruno, Berengar's disciple and Bishop of Angers; the powerful Count of Anjou also supported him. St. Paschasius, Ratramnus and Eriugena had been in good standing with the Church during the Carolingian Eucharistic controversy, and at first it was not clearly perceived why Berengar's opinions could not likewise be tolerated. But the Church of the 11th century was not the Church of the 9th, and whereas sacramental theology was still in a very formative stage is Ratramnus' day, by the time of Berengar it was developed with much more precision, such that Berengar's teachings were much more outside the pale of orthodoxy.
Berengar was again condemned by a regional synod summoned by the king in 1054. After this, Berengar appears to have repented; he signed formulas of faith at the Council of Tours (1055) and Rome (1059) affirming that after the consecration the "real and sensible" Body and Blood of Christ are present in the Holy Eucharist. However, Berengar would go back on his oaths and attack the formulary of Rome, which caused much of his support to evaporate, including that of his friend and disciple, Eusebius Bruno.
The remainder of Berengar's life is a sad tale; his doctrine is condemned so soundly and so repeatedly that it would be impossible to state that the Church's stance this point was ambiguous; he was condemned in 1075, 1076, 1078 and 1080; Ratramnus' book was also condemned during the controversy and later put on the Index.
Berengar finally signed a very explicit profession of faith in 1080, was reconciled with the Church and spent the last eight years of his life doing penance on the island of St. Cosme, home to a small priory in the midst of the Loire River outside of the city. There he died in union with the Church in 1088.
The Heresy of Berengar and its Importance
There are several things we can draw from the heresy of Berengar. First, it is interesting to note that, throughout the dispute, most of those who supported Berengar were secular princes (like the Count of Anjou) and lesser theologians; his opposition came mainly from bishops and the hierarchy, although the most eminent theologians of the day (Lanfranc, for example) were unanimous in their condemnation of Berengar. No great theologian of the age supported him. As in the case with St. Paschasius and Ratramnus, and we might add, in modern cases of widespread dissent like Humanae Vitae, the secularists and middling theologians stood on the side of dissent while it fell to the bishops, no doubt guided by the "sure charism of truth" that the bishops possess collectively in union with the pope, to state the truth clearly, no matter how unpopular it might have been to the theologians.
It is from the standpoint of Eucharistic apologetics, however, that the controversy over Berengar's teaching really takes on importance. Anti-Catholic writers will typically state that belief in transubstantiation was invented at the Fourth Lateran Council (1215), or will at least suggest the 11th century as the time when the Church first started teaching a change in the elements. The Berengar controversy blows away these assertions; as we have seen, Berengar was merely adding his two cents in a controversy that went back to the mid-9th century. The 9th century dispute between St. Paschasius and Ratramnus was not over the introduction of a novelty into the Church's theology. Both Paschasius and Ratramnus accepted that Christ was "really present" in the Eucharist, but the debate was on what manner of presence this was.
A Tradition had been handed on from the patristic age that the sacrament of the Eucharist was the Body and Blood of Christ; Christians, without interruption from the time of the Fathers onward, held that the manner in which Christ was present in the sacrament was a Real Presence. The point is nobody ever doubted the Real Presence, and the heresy of Berengar did not constitute a denial of the Real Presence in the strict sense. Berengar sought to explain the manner in which the Real Presence was effected, just as Ratramnus did before him. The fact that Berengar did not accept the concept of a substantial change in the elements at the time of consecration is no evidence that the Church at his time or before did not believe in the Real Presence; nobody ever seriously doubted the Real Presence, even if they did question the manner in which that Presence became Real - was it truly miraculous, or was it a spiritual transformation that, while supernatural, was not necessarily miraculous?
As the liturgy of the Church developed in the early Middle Ages, the consecration came to be regarded as the focal point of the Eucharistic mystery, and provides reason for the Western churches' emphasis on the consecration over the epiclesis as the moment when the Body of Christ becomes present. The subsequent developments in sacramental theology, including the institution of the Feast of Corpus Christi, the addition of the elevation of the host after consecration and the adoption of the term "Transubstantiation" in the mid-12th century, and the emerging distinctions of a sacramental mode of presence show that Berengar stood outside the direction that the Church's theology had been developing. And, if we apply the principle of Cardinal Newman that earlier Catholic teachings can be more clearly understood in light of subsequent developments, we see that the teachings of Ratramnus, Eriugena and Berengar on the "spiritual" presence of Christ in the Eucharist without a substantial change in the elements are outside the pale of orthodoxy, even in their own day, which is why men like St. Paschasius and Lanfranc of Bec, as well as the papacy itself, responded so vehemently against Berengar's hypotheses. Eucharistic doctrine might not have been perfectly worked out in the 11th century, but in the teaching of Berengar, with its adamant denial of a physical presence, the Church of his day knew something was wrong, which was why his teaching was unanimously condemned eight times during his life and even once after his death (1095). These facts do not make any sense if the Church was the one innovating with the insistence of a change in substance; but they do make perfect sense if Berengar was the one teaching novelty. It is a classic case of doctrine in a state of development, demonstrating how earlier teachings can be interpreted in light of later developments to identify the golden thread of orthodoxy that runs through the Church's teaching in all ages.
On the positive side, Berengar's heresy led to a further development of the concepts of what medieval theologians would describe as the sacramentum tantum (sacramental sign) and the sacramentum et res (the mystical reality), as well as to a further crystallization of the concepts of form, matter and accidental properties in the Eucharistic species. Perhaps most importantly, the controversy led the way to understanding the concept of Christ's sacramental mode of Presence in the Eucharist. The sacramental mode of being is more specific and particular than the omnipresence of the Word in all places and times throughout the Universe, which is predicated of the fact that God is a pure spirit and is eternal in power; nevertheless, it is different from His physical, historic presence on the earth, because those who encounter Christ in the sacrament encounter Him in a real way, but not in a carnal way. We truly receive the Body, Blood, Soul and Divinity of Christ, but not in a carnal sense in which we are gnawing on bone marrow or picking pieces of hair out from between our teeth. St. Paschasius had known from Tradition that Christ is truly and really present, but he lacked the vocabulary or the specificity to distinguish Christ's Real Presence from his fleshly, historic existence on the earth, which is why many who read his treatise found something awry in it. The sacramental mode of presence that was elucidated by the post-Berengarian theologians helped explain how the Church could at once affirm Christ's true, substantial Presence in the Eucharist in a special way different from His omnipresence while at the same time denying that Christ is present in a carnal manner in the Eucharist.
Negatively, we can see in the heresy of Berengar an emergence of the rationalist trend that would sour the latter Scholastic period. Though there is nothing known for certain, contemporaries of Berengar mentioned that he also denied the extent of the Church's spiritual power, the legitimacy of infant baptism, and the indissolubility of marriage; while we do not know if these charges are accurate, if so, they demonstrate a trend in Berengar's thought towards denying the objective spiritual realities brought about by the sacraments (objective baptismal regeneration, the bond if matrimony, etc), what later theologians would call the ex opera operato manner in which the sacraments produce their effects. This rationalist critique of the objective nature of the sacraments would rear its head again in the 14th century and come to fruition with Luther's insistence that faith alone (a completely subjective element) is the operative principle behind any effect wrought by grace.
Thus, though the heresy of Berengar split French church during the 11th century, it was the occasion of great developments in medieval sacramental theology that would culminate in the theology of Peter Lombard and Aquinas in the 12th and 13th centuries.
 M. Clerval, Les Ecoles de Chartres au Moyen Age, Chartres, 1895, cited in"Berengarius of Tours." The Catholic Encyclopedia. Vol. 2. New York: Robert Appleton Company, 1907. 23 Jan. 2013 <http://www.newadvent.org/cathen/02487a.htm>.
 Hincmar of Rheims, De praedestinatione Dei et libero arbitrio, 31
 This work, also entitled De Corpore et Sanguine Domine, appears to have been written by the Pope as a private theologian
 He would later become Archbishop of Canterbury and predecessor to St. Anselm.
 The term was, ironically, first coined by Hildebert of Lavardin, believed to be a one-time disciple of Beregar."Berengarius of Tours." The Catholic Encyclopedia. Vol. 2. New York: Robert Appleton Company, 1907. 24 Jan. 2013 <http://www.newadvent.org/cathen/02487a.htm>.