In Late Antiquity, the term “catechism” (Latin catechismus from Greek katéchesis, “oral instruction”) came into use for the instruction of adult catechumens; when infant baptism was introducted in the 2nd/3rd century, it was applied to the instruction of the faithful (Catechetics). In the early modern era, the term came to be applied to systematically organized works designed for elementary religious instruction. Other terms used included ench(e)iridion (Greek, “small handbook”), instituti…