Article I: On the Existence of the Sacrament of the Eucharist

S. Th. III, q. 73, a. 1.

203. Thesis. The Eucharist is a true and properly so-called sacrament of the New Law. - Thus it is declared by the Fourth Lateran Council, c. 1, and Florence, decree for the Armenians; and it is defined by Trent, sess. 7, can. 1; nor is it denied by Protestants, a few excepted.¹

¹ The Quakers and Unitarians deny it: these say that it is a mere commemoration of the supper.

It is proved: 1. From the fact that the definition of sacrament belongs to the Eucharist. For it is a) a sensible sign through the species of bread and wine and the words of consecration; b) of a sacred thing: for the species no longer signify the substance of bread and wine, but the body and blood of Christ; c) insofar as it sanctifies men: for the body and blood of Christ are ordered to the spiritual refreshment of the soul, according to John VI, 48-59: He who eats this bread shall live forever; whence it is a practical sign of sanctification; d) instituted in perpetuity by Christ the legislator of the New Law (Luke XXII, 19).

2. From perpetual tradition, which is clear from the Rituals, the Fathers, and the practice of the Church.

3. By reason of fittingness: just as for bodily life generation is required, through which man receives life, and increase, by which he is brought to the perfection of life, so also nourishment is required, by which he is preserved in life; and therefore just as for spiritual life there must be Baptism, which is spiritual generation, and Confirmation, which is spiritual increase, so also the sacrament of the Eucharist, which is spiritual nourishment.