signs, the faithful receive the body of Christ not in veritate, but in figura, in mysterio, in virtute (figure, mystery, power). Ratramnus opposed Capharnaitic tendencies but in no way betrayed a symbolist understanding such as that of 11th-century Berengarius. Radbertus, on the other hand, developed the realism of the Gallican and Roman liturgy and the Ambrosian theology of the identity of the sacramental and historical body of the Lord. The dispute ended with Radbertus's letter to Frudiger, in which he stressed further the identity of the sacramental and historical body of Christ, but met the opposing view to the extent of emphasizing the spiritual nature of the sacramental body. Friedrich Kempf comments: "Since Paschasius had identified the Eucharistic and the historical body of the Lord without more precisely explaining the Eucharistic species, his teaching could and probably did promote a grossly materialistic 'Capharnaitic' interpretation". The question of the nature of the Eucharist became virulent for a second time in the Western Church in the 11th century, when Berengar of Tours denied that any material change in the elements was needed to explain the Eucharistic presence. This caused a controversy which led to the explicit clarification of the Catholic doctrine of the Eucharist. In 1215, the Fourth Lateran Council used the word transubstantiated in its profession of faith, when speaking of the change that takes place in the Eucharist. It was only later in the 13th century that Aristotelian metaphysics was accepted and a philosophical elaboration in line with that metaphysics was developed, which found classic formulation in the teaching of Saint Thomas Aquinas. It was only then that Scholasticism cast Christian theology in the terms of Aristotelianism. The metaphysical aspects of the real presence of Christ in the Eucharist were firstly described since the time of the Latin juvenile treatise titled De venerabili sacramento altaris (On the reverend sacrament of the altar). During the later medieval period, the question was debated within the Western Church. Following the Protestant Reformation, it became a central topic of division amongst the various emerging confessions. The Lutheran doctrine of the real presence, known as the "sacramental union", was formulated in the Augsburg Confession of 1530. Luther decidedly supported this doctrine, publishing The Sacrament of the Body and Blood of Christ—Against the Fanatics in 1526. Saying that "bread and body are two distinct substances", he declared that "out of two kinds of objects a union