Summa Theologiae Moralis, vol. I: De Principiis

S. Th. II-II, q. 16.

789. By natural-divine law the precept of faith is given, obliging under grave obligation, as is clear

1) by reason: for it being supposed that God reveals, reverence toward him demands that we believe him;

2) from Scripture, imposing the act of faith as a means of justification, and establishing the command: He who does not believe shall be condemned (Mk. XVI, 16; Jn. III, 16 and at the same time I Jn. III, 23; cfr. prop. 16 condemned by Innocent XI; C. Vat., sess. 3, c. 3, can. 1).

Which precept is both negative, by which we are forbidden to deny faith or to doubt about it, and this obliges always; and affirmative, by which we are obliged to elicit the act of faith, and this does not oblige always.

790. The virtue of faith itself and the precept oblige us to elicit the act of faith, and indeed under grave obligation:

A. per se, i.e. in the circumstances common to the condition of all men. For it is altogether necessary, indeed and the greatest precept, to tend toward the supernatural last end; which however we do not do except by acts of faith, hope and charity. Now this is most necessary¹

1) at the beginning of the use of reason, when man is bound to turn himself to God and to choose for himself the last end;

2) at the moment of death (i.e. towards the end of life), when he is about to reach the end;

3) several times in life. For it is not enough that we tend to God once or twice, but during our whole life we must acknowledge our dependence on God; whence these acts must be elicited more frequently². Which some determine by saying: at least once a year, others every month (S. Alphonsus), or even every week (Scotus), others finally probably three or four times a year.

If at the beginning of the use of reason, the supernatural end were unknown for defect of the proposal of faith, man will be bound to the act of faith as soon as it is sufficiently proposed.

B. per accidens, i.e. on the occasion of some special circumstance:

1) when a temptation against faith arises which is hoped to be overcome only by an act of faith; which however does not suit the scrupulous who torment themselves by repeating that act, whence they themselves may despise these temptations by diverting them to other things;

2) when faith has been lost, which is done by the sin directly contrary, namely infidelity, because the tendency toward the last end thus taken away must be renewed and restored;

3) while we manifest faith outwardly, e.g. in the profession of faith, otherwise that manifestation would be pretense.

791. Other virtues and precepts oblige us sometimes to elicit the act of faith, at least implicitly:

1) when temptations against other virtues arise, which are hoped to be overcome only by an act of faith;

2) when one must or intends to receive the sacraments;

3) when one must or intends to exercise an act of another virtue which cannot be exercised without faith, e.g. prayer, hearing Mass, contrition for sins, etc., and so we are obliged to faith when we are obliged to hope or charity.

But in these cases the obligation does not arise from the precept of faith itself; whence, omitting this act, we do not sin against this virtue, but only against the other precept by which it was required.

792. In the positive divine law there is no explicit precept of believing in God. — For, as S. Thomas has it, a. 1: "Law is not imposed by any lord except over his subjects; and therefore the precepts of law presuppose the subjection of each one receiving the law to him who gives the law. Now the first subjection of man to God is through faith, according to that of Heb. XI, 6: He who approaches God must believe that he is; and therefore faith is presupposed to the precepts of law; and on this account Exod. XX, 2, that which is of faith is set before the precepts of the law, when it is said: I am the Lord thy God... and afterwards immediately begins to speak of the precepts.

But because in faith many things are contained ordered to faith, which we believe God to be, which is the first and principal among all things to be believed..., therefore, presupposed faith in God, by which the human mind is subjected to God, precepts can be given about other things to be believed".

Nevertheless

a) "in the old law the secrets of faith were not to be set forth to the people; and therefore, presupposed faith in one God, no other precepts are given in the old law about faith";

b) but, supposed subjection to God through faith in one God, in the new law precepts about other things to be believed were added, such as about the incarnation, by which one is God and man. Whence Christ says, Jn. XIV, 1: You believe in God; believe also in me (ad 2);

c) indeed presupposed faith in one God, even in the old law prohibitive precepts were given, by which men were forbidden from particular defects and sins through which faith could be corrupted (ad 3);

d) indeed presupposed the subjection of man to God through faith, in the old law there were already given precepts pertaining to the confession of faith or to the doctrine of faith, but not however to faith itself (ad 4).

The precepts which pertain to the doctrine of faith pertain to the intellect and to knowledge, which are read more abundantly in the New Testament both in the evangelical and in the apostolic doctrine (a. 2).

793. Practical admonitions. — 1. The precept of faith is satisfied even if the act of faith is not elicited ex professo and explicitly, but only implicitly, fulfilling another precept, e.g. by receiving a sacrament, which cannot be fulfilled without faith (cfr. n. 791).

2. Penitents are not to be examined nor interrogated about the fulfillment of this precept: for those who live Christian lives have more frequent occasion of exercising it; for others however, from those things which they confess, it is easily clear whether they have fulfilled it or not.

3. Priests are especially to exhort the faithful to exercise faith frequently; and in danger of death, with the sick reciting the act of faith.