Chapter — Slater, Manual of Moral Theology
Chapter III. The Subject of Orders
To be able to receive Orders validly, the subject must be of the male sex and baptized (Can. 968). It has always been understood in the Church that women cannot receive Christian Orders. Moreover, an adult must have at least an habitual and express intention to receive ordination (unless indeed he is an imbecile and has never had the use of reason).
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Many qualities and conditions are requisite for the lawful reception of Orders about which something must here be said; the fuller treatment of this matter belongs to canon law.
As we saw when treating of the clerical state, one who aspires to Orders must be of good life and must be called by God.
At least the Orders which are sacraments should be received in the state of grace, and Canon 1001 prescribes that before receiving the first tonsure and minor Orders the ordinand should devote at least three whole days to spiritual exercises, and before receiving sacred Orders he should devote at least six whole days to them.
In order that one may be lawfully ordained Canon 974 requires: (1) The reception of the sacrament of Confirmation; (2) moral conduct agreeably to the Order to be received; (3) the canonical age; (4) the required knowledge; (5) the reception of the lower Orders; (6) the observance of the interstices; (7) a canonical title if there is question of major Orders.
The subdiaconate may not be conferred before the completion of the twenty-first year of age, the diaconate before the completion of the twenty-second, and the priesthood before the completion of the twenty-fourth (Can. 975).
No one, whether secular or religious, is to receive the first tonsure before beginning his course of theology (Can. 976).
The subdiaconate may not be given except at the end of the third year of the course of theology, the diaconate only at the beginning of the fourth year, and the priesthood only after the middle of the fourth year (Can. 976, sec. 2).
Orders should be conferred by degrees, so that ordinations leaps and bounds are altogether prohibited (Can. 977).
Canon 978 prescribes that the interstices are to be observed, and during them those who have been promoted should exercise themselves in the Orders received according to the directions of the bishop.
The interstices between the first tonsure and the Order of door-keepers and between the minor Orders are left to the prudent judgement of the bishop; one year should elapse between the Order of acolytes and the subdiaconate; three months between the subdiaconate and the diaconate.
Without special leave of the Roman Pontiff minor Orders may never be given with the subdiaconate or two sacred Orders on one and the same day, and any custom to the contrary is reprobated; it is also forbidden to give the first tonsure together with one of the minor Orders, or all the minor Orders at once.
A bishop must have completed his thirtieth year.
By common law sacred Orders should be conferred during Mass on the Saturdays in Ember Week, or before Passion Sunday, or before Easter Sunday. For grave reason a bishop can confer them on any Sunday or holiday of obligation.
The first tonsure may be conferred on any day and at any time; minor Orders on Sundays and on doubles, in the morning (Can. 1006).
Those who receive sacred Orders must communicate in the Mass of ordination (Can. 1005).
The Church does not wish her clergy to have to beg or to exercise some unbecoming trade in order to gain a livelihood, so she requires that to be admitted to sacred Orders a cleric must have a title, as it is called, or a certain guarantee of decent support. Various titles are recognized by ecclesiastical law, such as a benefice, pension, patrimony, poverty for religious, a common table, the Mission, and others. If a cleric already ordained loses the title of his ordination he should find another, unless in the bishop’s judgement his decent support is otherwise provided for (Can. 980).
Before ordination regulars must be solemnly professed, unless they have a special privilege by which simple profession suffices.
After ordination a priest pays homage to the bishop and solemnly promises obedience to his ordinary. He undertakes no new burden by this promise; he simply binds himself anew to pay canonical obedience to the bishop in all matters subject to his authority; and a secular priest obliges himself not to leave the diocese for which he was ordained without the leave of his bishop.
p. ii, 186–187