With respect to the abortion issue, the principle in question is the moral impossibility for a Catholic to cooperate in an act or an institution that is "intrinsically evil." Now, something that is "intrinsically evil" is not just a bad thing - it is a heinous thing, trumping all other moral considerations, and we can never legitimately commit the act ourselves or approve of it in anyone else. Casting a vote for a candidate who forcefully advocates the killing of innocent unborn babies shows approval or unacceptable toleration of that heinous crime against humanity, and Catholics can never do it in good conscience. The Catechism of the Catholic Church calls such an attitude and action "formal cooperation" in evil (#2272). This does not mean that I commit the evil myself. It means that I agree with it and have made it possible for a person in public office to continue and/or advance that evil in my society.
Formal cooperation in the evil act of another is a sin, and depending on the gravity of the person's evil act, formal cooperation in it can be a mortal sin. Since procured abortion is an intrinsically evil act, and all promotion of it fits into the same moral category, voting for a person who forcefully advocates it must be a mortal sin. Add to the sin of formal cooperation in evil the sin of disobedience to legitimate Church authority. To date the USCCB and more than a dozen US bishops and state bishops' conferences have clarified these principles for Catholics, and their teachings couldn't be clearer.
Further, add the sin of scandal that a regrettable number of priests and religious are giving by their appalling disingenuousness about Church teachings both in and out of the pulpit. Catholic parents and teachers equally give scandal when they do not teach their children the principles that undergird moral behavior or properly form their consciences according to the Truth that is in Christ.
Some ask if a Catholic may vote for someone whose policies would advance an agenda that is mostly in line with the Catholic Church's teaching? Also, what if the Catholic disagrees with the candidate's position on abortion but still wants to vote for this candidate for other reasons consistent with our values? Here the Church uses the term "proportionate reason" to indicate that there must be some kind of balance in the candidate's position that indicates it is likely that a greater good would be accomplished for society despite the evil he or she advocates. Proportionate reasoning usually has to do with positions that are not intrinsically evil in themselves or that, if they are, would constitute such a minimal part of the platform that they would be "outweighed" somehow in the grand scheme of the candidate's public service. According to the above principle, however, the degree to which the candidate would promote something as heinous as abortion can literally nullify all the other "good" that he or she would do for humanity! When the fundamental right to life is denied in society, all other rights and goods are therefore threatened. The very moral foundation of a people is eroded. So the answer has to be no, it is not legitimate to disagree on abortion and still vote for a radical abortion candidate.
May a Catholic vote for an "imperfect" candidate if the radical abortion candidate is worse? The Church says yes, but only if the vote is not expressed as an agreement with the "imperfect" elements of the candidate's policies and only if the vote is intended to limit the evil that other candidate would inevitably do.
It is truly regretful that we have gotten to the point where we might have to surrender some of our basic values in the voting booth because we have not successfully insisted on the very best candidates for public office to serve the common good. That is a discussion for another day, but I anticipate that if Catholics do not assert Catholic values forcefully in elections and public policy from here on out, we may be faced in future elections with no choice whatsoever that can morally satisfy the Catholic conscience. Heaven help and guide us all on November 4th.
SL Action Items
Bishop Robert W. Finn: Freedom of Choice Act Would Remove All Limitations on Abortions
Sincerely Yours in Christ,
Rev. Thomas J. Euteneuer,
President, Human Life International