Conflict of duties or choice of a lesser evil
The pastoral note of the French episcopate of November 1968 undermined Humanæ vitæ by invoking the notion of conflict of duties or, what is the same, the notion of conflict between two evils from which one would choose the lesser of two evil.
In fact, the common expression of “lesser evil” is only found among the traditional authors to say that it can be tolerated in the case of an “act with double effect”. What tolerance means is that eventually it is alright not to prevent the occurrence of a lesser evil when one wants to provide a greater good or prevent a greater evil (Mt 13, 24-30: The Master of the harvest tolerates the growth of the cockle, because lest perhaps gathering up the cockle, one roots up the wheat also together with it). So, one can execute an act (for example, give an analgesic to a very sick person), that will carry a good which we desire (soothe the pain), but that will also have a bad unwanted effect (narcosis can speed up the moment of death). In other words, evil, in this case, is not a means that is desired but a consequence tolerated. But, we can never do evil (euthanized a sick person) to obtain a good (the shortening of his pain). For a good end does not excuse an evil means (Rm 3, 8).
Yet, it can be difficult, in some cases, to draw a line between a medical act whose end is to soothe pain and the act whose end is to cause death. Or, in the same field, to distinguish between euthanasia and the rejection of the use of intensive medication. The question is out of order when the act is, in its essence, contrary to the norm that the soul carries, image of God Creator: we can never execute an act intrinsically evil, contrary in itself to the law inscribed by God in the heart of man (kill the innocent, destroy innocent populations, carry out an act of generation distorted from its end). In this way, abortion is never allowed, even for therapeutic reasons. In this way also, a policy of nuclear deterrence that includes the intention, even conditional, to kill innocents (non soldiers), is immoral. Thus, disposing of marriage so to make procreation impossible is in itself a grave violation of moral law.
Don Pio Pace