From Iota Unum

40. A new attitude towards error.

The attitude to be adopted in regard to error is on the other hand a definite novelty, and is openly announced as being a new departure for the Church. The Church, so the Pope (in the speach opening Vatican II) says, is not to set aside or weaken its opposition to error, but "she prefers today to make use of the medicine of mercy, rather than of the arms of severity." She resists error "by showing the validity of her teaching, rather than by issuing condemnations." This setting up of the principle of mercy as opposed to severity ignores the fact that in the mind of the Church the condemnation of error is in itself a work of mercy, since by pinning down error those laboring under it are corrected and others are preserved from falling into it. Furthermore, mercy and severity cannot exist, properly speaking, in regard to error, because they are moral virtues which have persons as their object, while the intellect recoils from error by the logical act that opposes a false conclusion. Since mercy is sorrow at another's misfortune accompanied by a desire to help him (Summa Theological II, II, q30a1), the methods of mercy can only be applied to the person in error, whom one helps by confuting his error and presenting him with the truth; and can never be applied to his error itself, which is a logical entity that cannot experience misfortune. Moreover, the Pope reduces by half the amount of help that can be offered, since he restricts the whole duty of the Church regarding the person in error to the mere presentation of the truth: this is alleged to be enough in itself to undo the error, without directly opposing it. The logical work of confutation is to be omitted to make way for a mere didascalia (direct instruction) on the truth.

...men did not change their minds regarding their errors, but became entrenced in them instead, and gave them the force of law. The public and universal acdceptance of these errors became obvious with the adoption of divorce and abortion.