Martin Luther and Ulrich Zwingli are considered the vital figures of the Protestant Reformation. In this essay I will focus on the theological roots of the disagreements between Luther and Zwingli. It is noteworthy that both Luther and Zwingli were exposed to different influences which naturally affected their theological views. Zwingli was more radical, he was a republican and he was also a true Swiss patriot. Where Luther believed that the Gospel should be defended through the preaching of the Word, Zwingli was an advocate of using the sword in defense of the Fatherland and the Gospel. The root of the disagreements between Luther and Zwingli, an issue on which they could not find common ground, is the Eucharist. This is due to the clash between Zwingli's rational approach to understanding the Eucharist and Luther's more mystical approach to the Scriptures which leads to this. Subsequently, despite the face-to-face meeting at Marburg Castle, the obstinacy of both parties left them still in conflict with each other's interpretation. I will discuss how their views differ, especially regarding the Eucharist. First, both Luther and Zwingli had different philosophical educations and backgrounds. Luther was educated in the theories of William of Occam and was influenced by the belief that the truths of revelation are profound and go beyond reason. This belief held that it is not possible to explain the truths of revelations through reason. In contrast, Zwingli was educated in Thomism, in the works of Thomas Aquinas, who believed that the truths of revelation and reason were more in agreement than Occam. Furthermore Thomism emphasized the priority of divine grace and man as an instrument of divine predestination while Occam emphasized... in the middle of the paper... however Zwingli still refused on the grounds that this was still too close to the Roman transubstantiation. In conclusion, the difference in approach to the Scriptures heavily affects the interpretation and understanding that both Luther and Zwingli have of the Eucharist. For Luther, if Christ is not present at the Supper, then there is no place for the body of Christ as an essential element of our redemption. However, the ubiquity of Christ solves this problem. This belief is very mystical compared to Zwingli who argues that the belief that Christ is present at the Alter leads to forms of idolatry in which earthly objects are held above heavenly ones. Zwingli remains faithful to Aquinas's influence of reason and interprets the elements of the Eucharist to mean the body and blood of Christ rather than suggesting that Christ is present in his body in the bread..