1080. Presumption is rash, therefore, for the following reasons: (a) because it leads one to expect what is impossible according to the absolute or ordinary power of God (e.g., to share in some divine attribute, to sit at the right hand of Christ in glory), or (b) because it makes one expect to obtain supernatural goods in ways other than those ordained by God (e.g., to obtain forgiveness without repentance, to obtain glory without merits or grace).
1081. The nature of presumption as compared with temptation of God and blasphemous hope is as follows: (a) they are alike, inasmuch as all three wrongly expect something from God; (b) they differ, for presumption looks towards salvation and one’s own happiness, whereas temptation of God seeks rashly some sign from God as a proof that He is wise, good, powerful, etc., or that the person is innocent, holy, etc., and blasphemous hope expects that God will help one in working revenge or committing other sin.
1082. The Malice of Presumption.-(a) It is a sin, because it is an act of the will agreeable to false intellectual judgments, namely, that God will pardon the impenitent or grant eternal life to those who have not labored for it. (b) It is a mortal sin, since it does grave injury to the divine attributes. We cannot hope too much in God, but we can expect what a perfect God cannot grant; in this latter respect—that is, in its contempt of God’s majesty and justice—consists the offense of presumption. (c) It is a sin against the Holy Ghost, because it makes one despise the grace of God, repentance, etc., as if they were not necessary.
1083. The gravity of presumption as compared with other sins, is as follows:
(a) It is graver than sins against the moral virtues, because it is directly against God. Thus, theological presumption, being injurious to the power of God, is a more serious offense than moral presumption, which is an exaggeration of the power of man.
(b) It is less grave than despair, for, while presumption is a disregard of God’s vindictive justice, despair is a disregard of His mercy, and God’s vindictive justice is due to the sins of man, His mercy to His own goodness.
(c) Presumption is less grave, therefore, than unbelief and hatred of God, which, as said above, are more wicked than despair (see 1070).
1084. Presumption and Unbelief.—(a) Presumption is joined with unbelief whenever it proceeds from a speculatively false judgment about matters of faith. Persons, however, who are in error (e.g., Pelagians, Lutherans, Calvinists, etc.), may be in good faith, and hence guiltless of the formal sin of presumption. Examples: Caius expects to win heaven by his own unaided efforts (Pelagian presumption). Balbus expects to be equal in glory to the greatest Saints, and to be saved by the merits of Christ without repentance or observance of the Commandments (Lutheran presumption). Titus expects to be saved on the strength of wearing scapulars, practising certain devotions, or giving alms, while he wholly disregards church duties and important Commandments (Pharisaic presumption). Sempronius thinks that all members of his sect are predestined, and hence concerns himself little about the Commandments, being persuaded that all must end well with the elect (Calvinistic presumption).
(b) Presumption is committed without unbelief, when it proceeds from a practical judgment that one should act as if salvation were obtainable without merits or repentance, or as if natural efforts were alone sufficient, although speculatively one does not accept such errors (see 1067). The same is true when presumption springs from a failure to consider the divine justice or the established means of obtaining salvation.
1085. Presumption and Loss of the Virtue of Hope.—(a) Presumption properly so-called (i.e., hope of the impossible) takes away the virtue of hope, for it removes the motive and reasonableness of the virtue; now, the essence of true hope is a reasonable expectation, just as the essence of faith is assent to divine authority. Hence, he who expects future blessedness unreasonably (i.e., through his own efforts alone or through exaggerated mercy exercised by God), is not hopeful, but presumptuous.