CATECHESIS, in a general sense, denotes an instruction
Catechetic instruction given any person in the first rudiments of an art or science; but more particularly of the Christian religion. In the ancient church, catechetics was an instruction given vita voce, either to children, or adult heathens, preparatory to their receiving of baptism. In this sense, catechets stands contradistinguished from mythagogica, which were a higher part of instruction given to those already initiated, and containing the mysteries of faith. Those who give such instructions are called catechists; and those who receive them, catechumens.