“A sacrament is so termed because it contains something sacred. Now a thing can be styled sacred from two causes; either absolutely, or in relation to something else. The difference between the Eucharist and other sacraments having sensible matter is that whereas the Eucharist contains something which is sacred absolutely, namely, Christ’s own body; the baptismal water contains something which is sacred in relation to something else, namely, the sanctifying power: and the same holds good of chrism and such like.” -St. Thomas Aquinas
