Section — Prümmer, Manuale Theologiae Moralis
§ 1. On Infants and Impuberes as Subjects of Law
188. Notions. Before the first seven-year period has been completed, a man is called an infant, or child, or little one; from the seventh year until legal puberty has been attained (that is, until the fourteenth year of age has been completed, if he is male, and until the twelfth year of age has been completed, if she is female), a man is called impubes;59 then until majority (which is usually granted when the twenty-first year of age has been completed) he is called minor or underage;60 afterward, however, major or of age. An infant and an impubes are also called by the common name pupils. To a pupil a tutor is given; but to a minor a curator is given.
59 With regard to delicts, several writers perceive no serious reason why puberty in girls should be placed earlier than in boys; and therefore they demand the age of 14 years both for boys and for girls. Thus also Vermeersch, Theol. mor. I, n. 283.
60 Cod. iur. can. c. 88.
189. Principle 1. Infants are not held (unless something else is expressly provided by law) to human laws, even if they have in fact already attained the use of reason.
Thus the opinion today is certain.61 The reason is that infants before the first seven-year period has been completed are judged not yet habitually to enjoy the use of reason, and therefore are not subject to human laws, as was said. But if in an exceptional case infants have already obtained sufficient use of reason before the first seven-year period has been completed, certainly it is best that they be induced to the observance of ecclesiastical law proportioned to their own state, for example, of assisting at Mass, of abstaining from meats; yet no strict obligation of observing these laws exists. Wherefore the Angelic Doctor teaches:62 "The legislator attends to that which is held commonly and occurs in the greater number." There is also the common adage: "Those things which happen rarely legislators disregard."
Note. The precepts of confessing mortal sin and of receiving holy communion are not merely ecclesiastical precepts, but also divine. For this reason an infant who is certainly conscious of a mortal sin committed is held to confess; likewise an infant who has sufficient discretion must receive the Eucharist; nevertheless, in the rigor of law he is not held to observe the precept of the Eucharistic fast, since it is merely ecclesiastical.
61 Ibid., c. 12. Very rarely does the law expressly oblige infants; for example, it forbids their entrance into cloister, cc. 598 and 600.
62 S. theol. II-II, q. 147, a. 4.
190. Principle 2. Impuberes are held to human laws, and especially ecclesiastical laws, fitting to their state, provided, however, that they have in fact attained the use of reason and no special exemption has been granted to them from written or customary law.
The reason is that impuberes are judged to have sufficient habitual use of reason. If, however, in an exceptional case a man after the first seven-year period does not have the ready use of reason, he is not obliged by human laws.
There are some laws, both ecclesiastical and civil, to which impuberes are not subject, for example, the law of ecclesiastical fasting, several penal laws. Wherefore impuberes are excused from penalties latae sententiae, and should rather be corrected by educative punishments than by censures or other graver vindictive penalties.63 But from incurring episcopal reserved cases, impuberes are not exempt by common law; not rarely, however, they are exempt by the particular law of some dioceses.
63 Cod. iur. can. c. 2230.