The Eucharistic theology of any theologian can in principle be placed between two extremes: on the one hand is the ultimate realism - the complete identity between the body of Christ and the Eucharistic gifts, and on the other is the ultimate symbolism - the Eucharistic gifts only represent the body of Christ. The aim of this paper is to interpret the dogma of transubstantiation, which is closer to the extreme of realism. We first study its origin. It was developed in the theological treatises of the High Middle Ages. Its supreme philosophical-theological interpretation was given by st. Thomas Aquinas, and at the Council of Trent it has a central place in defining the Eucharistic doctrine. After the council, few Catholic theologians advocated any of the aforementioned extremes. With the advancement of science in the 20th century, the notion of substance was challenged, resulting in a discussion about transubstantiation dogma in the 1960s. In this discussion B. Welte, P. Schoonenberg, and E. Schillebeeckx are theologians with symbolist tendencies. In doing so, they rely on personalist philosophy and the philosophy of Martin Heidegger. Among those who, despite of the scientific knowledge of the 20th century, notice the permanently valid realistic core of the studied dogma, we present the thoughts of K. Rahner, R. Spaemann and J. Ratzinger.