Summa Theologiae Moralis, vol. I: De Principiis

S. Th. II-II, q. 18; de Virt., q. 4, a. 2 and 4.

816. The proximate subject of theological hope is the will. — It is proved: a habit resides where its act is; but the act of hope is a movement of the appetitive power; since however theological hope has as object not a sensible good but a divine good, it is not in the irascible appetite but in the will. Therefore the habit of theological hope also is in the will.

From this it follows that the act of hope is free, because it is an act of the will. Nor should one say: man necessarily wills his beatitude; therefore he necessarily hopes. For although man necessarily wills his beatitude considered in the abstract, he nevertheless freely chooses this or that, in the case God, as the object in which he constitutes his beatitude in the concrete.

817. The remote subject of hope can be known from the fact that the object of hope is a good, future, arduous, possible of attainment. Hence

1) hope does not remain in the blessed, because beatitude is not future for them. Nor can they hope for future glory of the body, because it has not the notion of the arduous;

2) in Christ there was not the virtue of hope, because beatitude was never future for him; he could however hope for the glory of the body which was arduous for him, inasmuch as it had to be merited by his passion. But he did not hope for it by theological hope, whose object, future beatitude, was lacking; the primary object being removed, the habit does not remain; — on the contrary, hope was in the B. Virgin;

3) in the souls of purgatory hope remains, because future beatitude is for them and arduous, inasmuch as it is to be obtained through pains. Nor does it hinder that beatitude is certain for them, for certitude is not contrary to the nature of hope;

4) in the damned hope does not remain, because beatitude is impossible for them.

818. Hope is infused together with sanctifying grace, faith and charity; it is lost a) directly by sins directly contrary, namely by despair, and by that presumption which removes the motive of hope; b) indirectly it is lost, when its foundation is destroyed: faith, which is done by the sin of infidelity.

819. The hope of wayfarers is certain. — For although certitude essentially belongs only to the act of the intellect, nevertheless the acts of other powers can participate in it inasmuch as they are moved by the intellect infallibly toward something. The act of hope therefore is certain with a certitude derived from the certitude of faith. Hence:

a) Hope is absolutely certain and infallible on its part, i.e. on the part of the motive, for by faith it is certain that the omnipotence of God does not fail in helping; whence faith moves the will, so that it is without any fear, diffidence, hesitation that something necessary for salvation fails on God's part, but that it firmly adheres to God helping.

b) However on our part, i.e. on the part of the subject hoping, hope is not certain because, although God will not fail us, nevertheless our free will can fail, put an obstacle of sin, and so fail God.

On our part therefore hope has only a conditional certitude by which we are certain of obtaining eternal life, if we use the means of salvation and persevere until the end. Whence hope stands together with fear that something may fail on our part, on account of our fragility and instability. Therefore the Apostle, I Cor. X, 12: "He who thinks he stands, let him see that he does not fall", and Phil. II, 12: "With fear and trembling work out your salvation".

Which however is per accidens in relation to the nature of hope, for it does not arise from its object or motive, but from the conditions of the subject in which hope inheres. Whence simply hope is certain. Which the Scriptures teach Ps. XXX, 2; Eccli. II, 6, 12-13; Rom. V, 2; Heb. VI, 18, 19; II Tim. I, 12.

The whole doctrine is set forth by the Council of Trent, sess. 6, c. 9 and 13, can. 18 and 16.