Thomas Aquinas

“ Art. 2 - Whether a determinate quantity of bread and wine is required for the matter of this sacrament? Objection 1: It seems that a determinate quantity of bread and wine is required for the matter of this sacrament. Because the effects of grace are no less set in order than those of nature. But, "there is a limit set by nature upon all existing things, and a reckoning of size and development" (De Anima ii) . Consequently, in this sacrament, which is called "Eucharist," that is, "a good grace," a determinate quantity of the bread and wine is required. ”

“ Since the mixing of water with the wine is not necessary for the sacrament, it does not matter, as to the essence of the sacrament, what kind of water is added to the wine, whether natural water, or artificial, as rose-water, although, as to the propriety of the sacrament, he would sin who mixes any other than natural and true water, because true water flowed from the side of Christ hanging on the cross, and not phlegm, as some have said, in order to show that Christ's body was truly composed of the four elements ”

“ Sometimes there is such corruption of the bread that the species of bread is lost, as when the continuity of its parts is destroyed, and the taste, color, and other accidents are changed; hence the body of Christ may not be made from such matter. But sometimes there is not such corruption as to alter the species, but merely disposition towards corruption, which a slight change in the savor betrays, and from such bread the body of Christ may be made: but he who does so, sins from irreverence towards the sacrament. ”