Born in 785, Radbertus was orphaned and abandoned on the steps of St Mary’s convent in Soissons (France), where he was raised by the nuns, developing a close bond with the Abbess Theodrara (a cousin of Charlemagne).
Radbertus took the Benedictine habit, but subsequently decided that, having spent his entire life inside convents and monasteries, he needed to experience the wider world, so he left his monastery and for a while enjoyed a worldly lifestyle – all of which served to convince him that he really was called to the life of the cloister.
Radbertus elected to enter the Abbey of Corbie where two of Theodrara’s brothers, Adalard and Wala, were monks, (Adalard was the Abbot, and Wala was later to succeed him in that role), and he duly devoted himself to a life of prayer, study and monastic observance.
His knowledge of Greek and Hebrew – together with the family connections of Adalard and Wala with Charlemagne) meant that Radbertus soon became a prominent figure in the Carolingian Renaissance, and to this end he was sent along with Adalard to establish monasteries in Saxony.
Charlemagne’s evangelistic program in Saxony had hitherto involved beheading 4500 hostages in order to persuade the wider population to accept forced baptism, and the efforts of Radbertus and Adalard to evangelize by establishing centers of prayer and study represented a welcome counterbalance to Charlemagne’s heavy-handed (not to mention brutal) approach.
Always a humble man (he described himself as the “dishwater” of monastic life) Radbertus developed a reputation both as a preacher and as a public lecturer. As director of the schools of Corbie (he had helped to found a New Corbie in Westphalia), he was also responsible for a flowering of Carolingian scholarship as represented by (among others) Blessed Adalard the Younger, and Saints Anscharius, Hildemar, and Odo.
He also exercised the function of master of novices, and so became instrumental in shaping the moastic and spiritual development of monks in the Corbie schools, where, in spite of all his academic and administrative responsibilities, he was exemplary in his attendance in choir and in his observance of the rule.
In 844 he became Abbot, but the additional administrative burdens, together with political tensions within the Corbie monasteries, meant that this was an unhappy time for him, and he resigned in 851, retiring to the abbey of Saint-Riquier in order to follow a life of prayer and study before returning to Corbie in order to die (some time between 860 and 865).
Radbertus was the author of a large corpus of theological writings, the most significant of which was the hugely influential De Corpore et Sanguine Domini – a full-length treatise on the Eucharist (the first in Western theology) which drew sharp criticism from (among others) his own abbot, Ratramnus (who succeeded Wala in that role).
Taking his lead from St Ambrose of Milan, Radbertus insisted that the true, historical body of Jesus Christ is literally present in Eucharist, in such a way that, in receiving Christ’s true body and blood, the communicant is united with Christ physically and directly.
Radbertus affirmed that the image of God is located in the whole human person – body and soul (and not just soul) – with the result that salvation is to be seen in terms of union between the whole human person and the whole person of Christ (body, blood, soul and divinity) who makes himself efficaciously, literally and physically present (and communicable) in the Eucharist.
Critics such as Ratramnus felt that Radbertus went too far in emphasizing the sheer fleshliness of Christ’s eucharistic presence, and preferred to focus on the idea of a metaphorical and spiritual presence, but Radbertus’s rejection of the dualistic separation of body and soul (which some Latin theologians had imported from Greek theology) meant that, for him, the opposition of physical presence and spiritual presence was a false distinction.
His sound instincts in this regard served to preserve the best traditions of patristic writing on the subject (St Irenaeus, St Ambrose), and to prepare the way for a more complete articulation of the idea of the Real Presence by St Thomas Aquinas and other mediaeval authors.
The rebuttal penned by Ratramnus was written at the instigation of the King, Charles the Bald, who was initially unhappy with aspects of De Corpore et Sanguine Domini, but Charles eventually came round to a more positive assessment, with the result that Radbertus’s approach to understanding the Real Presence came to exercise a growing influence on the development of Latin eucharistic theology.