What do they mean by “presumption”?
From the Catholic Encyclopedia:
Presumption
(Latin praesumere, "to take before", "to take for granted").Presumption is here considered as a vice opposed to the theological virtue of hope. It may also be regarded as a product of pride. It may be defined as the condition of a soul which, because of a badly regulated reliance on God's mercy and power, hopes for salvation without doing anything to deserve it, or for pardon of his sins without repenting of them. Presumption is said to offend against hope by excess, as despair by defect. It will be obvious, however, to one who ponders what is meant by hope, that this statement is not exact. There is only a certain analogy which justifies it. As a matter of fact we could not hope too much, assuming that it is really the supernatural habit which is in question.
Suarez ("De spe", disp. 2a, sect. 3, n. 2) enumerates five ways in which one may be guilty of presumption, as follows:
The root-malice of presumption is that it denies the supernatural order, as in the first instance, or travesties the conception of the Divine attributes, as in the others. Theologians draw a sharp distinction between the attitude of one who goes on in a vicious career, precisely because he counts upon pardon, and one whose persistence in wrongdoing is accompanied, but not motivated, by the hope of forgiveness. The first they impeach as presumption of a very heinous kind; the other is not such specifically. In practice it happens for the most part that the expectation of ultimate reconciliation with God is not the cause, but only the occasion, of a person's continuing in sinful indulgence. Thus the particular guilt of presumption is not contracted.
- by hoping to obtain by one's natural powers, unaided, what is definitely supernatural, viz. eternal bliss or the recovery of God's friendship after grievous sin (this would involve a Pelagian frame of mind);
- a person might look to have his sins forgiven without adequate penance (this, likewise, if it were based on a seriously entertained conviction, would seem to carry with it the taint of heresy);
- a man might expect some special assistance from Almighty God for the perpetration of crime (this would be blasphemous as well as presumptuous);
- one might aspire to certain extraordinary supernatural excellencies, but without any conformity to the determinations of God's providence. Thus one might aspire to equal in blessedness the Mother of God;
- finally, there is the transgression of those who, whilst they continue to lead a life of sin, are as confident of a happy issue as if they had not lost their baptismal innocence.
The desire to undertake, or the actual undertaking of, what is above one's capacity. It is a result of pride, which makes a person overestimate his abilities and blinds him to his deficiencies. It also leads one to expect graces from God without doing anything to obtain them, and even when acting the opposite, as when sinning, the person presumes that forgiveness is assured. (Etym. Latin praesumere, to suppose, take for granted.)