§ 3.  Catechumens.  The term Catechumen denoted a person who was receiving instruction in the Christian religion with a view to being in due time baptized.  Such persons were either converts from Paganism and Judaism, or children of Christian parents whose Baptism had been deferred.  For though the practice of Infant-Baptism was certainly common in the Early Church Cf. Iren. II. c. xxii. § 4:  “Omnes enim venit per semet ipsum salvare; omnes, inquam, qui per eum renascuntur in Deum, infantes, et parvulos, et pueros, et juvenes, et seniores.  Cf. Concil. Carthag. iii. Epist. Synod. (Cypriani Ep. lix. vel lxiv. Routh. R. S. iii. p. 98.), it was not compulsory nor invariable.  “In many cases Christian parents may have shared and acted on the opinion expressed by Tertullian in the second century, and by Gregory Nazianzen in the fourth, and thought it well to defer the Baptism of children, cases of grave sickness excepted, till they were able to make answer in their own name to the interrogations of the baptismal rite Dict. Chr. Antiq. “Baptism,” § 101.  Tertull. De Baptismo, c. xviii.  “And so, according to the circumstances, and disposition, and even age of each individual, the delay of Baptism is preferable; principally, however, in the case of little children.”  Cf. Gregor. Naz. Orat. 40 De Baptismo, quoted by Bingham, xi. c. 4, § 13..”