The Principle of Double Effect is used to determine when an action which has two effects, one good and one evil, may still be chosen without sin. This principle is attributed to St. Thomas Aquinas, who used it to show that killing in self-defense is justified (Summa Theologiae I-II q64 art. 7).
With respect to voting, it would allow under certain conditions the toleration of the unintended evil of another for a proportionate reason. All four conditions must be satisfied:
- The action must be morally good, or indifferent, as to object, motive and circumstances.
- The bad effect(s) may only be tolerated, not directly willed.
- The good effect must be caused at least as directly as the bad.
- The good effect(s) must be proportionate to compensate for the bad effect(s).
Catechism of the Catholic Church 1755
A morally good act requires the goodness of the object, of the end, and of the circumstances together. An evil end [motive] corrupts the action, even if the object is good in itself (such as praying and fasting "in order to be seen by men"). The object of the choice can by itself vitiate an act in its entirety. There are some concrete acts - such as fornication - that it is always wrong to choose, because choosing them entails a disorder of the will, that is, a moral evil.
Catechism of the Catholic Church 1756
It is therefore an error to judge the morality of human acts by considering only the intention that inspires them or the circumstances (environment, social pressure, duress or emergency, etc.) which supply their context.
Voting is a morally good action, but voting for any candidate, for any office, is typically to accept the good the candidate will do if elected, along with any evil he intends to do or may do. In determining the bad effects that may have to be tolerated, primacy of consideration belongs to the Non-Negotiables (life, marriage and family, religious freedom), since complex negotiable issues involve opinions about means, not essential goods/intrinsic evils.
Catechism of the Catholic Church 1737
An effect can be tolerated without being willed by its agent; for instance, a mother's exhaustion from tending her sick child. A bad effect is not imputable if it was not willed either as an end or as a means of an action, e.g., a death a person incurs in aiding someone in danger. For a bad effect to be imputable it must be foreseeable and the agent must have the possibility of avoiding it, as in the case of manslaughter caused by a drunken driver.
Catechism of the Catholic Church 1756
... There are acts which, in and of themselves, independently of circumstances and intentions, are always gravely illicit by reason of their object; such as blasphemy and perjury, murder and adultery. One may not do evil so that good may result from it. [intrinsically evil means are different than unwilled effects]
"One may not do evil that good may come of it," is an ancient axiom of morality. As noted under the subject of moral cooperation, we may not formally will another’s evil, provide immediate material support for it, or even mediate material support. We may, however, tolerate it as remote mediate material cooperation, but only when there is a serious proportion, as discussed under no. 4 below.
Such unintended evil effects are morally different than using evil means to achieve an end. Something that is used as a means is by its nature intended.
Catechism of the Catholic Church 1737
An effect can be tolerated without being willed by its agent; for instance, a mother's exhaustion from tending her sick child. A bad effect is not imputable if it was not willed either as an end or as a means of an action, e.g., a death a person incurs in aiding someone in danger. For a bad effect to be imputable it must be foreseeable and the agent must have the possibility of avoiding it, as in the case of manslaughter caused by a drunken driver.
The directness meant in this principle refers to causality, not time. In the Catechism’s example the same action which provides care for the child also causes the harm to the mother. In the use of medicine or radiation for treatment, the bad effects often occur before the good of health is attained. Yet, in both cases, the effects proceed as directly from the cause.
This is the principal of proportionality. It forbids the toleration of effects that are not seriously proportionate to the good effects that are expected from the action.
Establishing a just wage for workers is desirable by Catholic social teaching. However, this good effect can never be proportionate enough to compensate for the evil of abortion, the attack on marriage and family, or the loss of religious freedom (the Non-Negotiables). These are categorically and qualitatively different goods.
Therefore, a basket of non-negotiables improving the quality of life of hundreds of millions cannot justify the toleration of the killing of one million human beings annually through abortion. This is an absurd calculus, that those who employ it would reject if applied in many historical contexts in which millions were killed to achieve economic and other political objective.
The Nota Bene of then Joseph Cardinal Ratzinger at the end of his July 2004 letter to the U.S. Bishops on "Worthiness to Receive Holy Communion" is often cited in a proportionalist fashion to equate a basket of lesser issues with the greater and essential issues. He wrote,
A Catholic would be guilty of formal cooperation in evil, and so unworthy to present himself for Holy Communion, if he were to deliberately vote for a candidate precisely because of the candidate’s permissive stand on abortion and/or euthanasia. When a Catholic does not share a candidate’s stand in favor of abortion and/or euthanasia, but votes for that candidate for other reasons, it is considered remote material cooperation, which can be permitted in the presence of proportionate reasons.
It is clear that he was speaking within the context of the Catholic moral tradition outlined above, and not in support of a utilitarian ethic.
The need for a sufficient proportion of good effects in order to tolerate the evil effects using the Principle of Double Effect must be distinguished from the condemned moral theories of consequentialism and proportionalism. Popular especially among European and American theologians after Vatican II, they argued that in determining moral lawfulness the end (intention) could justify an otherwise evil act (proportionalism), or, the foreseen good effects could justify an action that previously has been judged to be morally evil.
These theories denied that any act was intrinsically evil by its object alone, apart from its intention and circumstances. Even abortion, contraception, adultery and other intrinsic evils, which the entire moral tradition has condemned, could, in some cases, be morally good by reason of their intention or consequences.
Pope St. John Paul II, in his Encyclical Veritatis Splendor, specifically condemned these theories.
... "consequentialism" or "proportionalism." The former claims to draw the criteria of the rightness of a given way of acting solely from a calculation of oreseeable consequences deriving from a given choice. The latter, by weighing the various values and goods being sought, focuses rather on the proportion acknowledged between the good and bad effects of that choice, with a view to the "greater good" or "lesser evil" actually possible in a particular situation.
The teleological ethical theories (proportionalism, consequentialism), while acknowledging that moral values are indicated by reason and by Revelation, maintain that it is never possible to formulate an absolute prohibition of particular kinds of behaviour which would be in conflict, in every circumstance and in every culture, with those values.
Veritatis Splendor 76
... Such theories however are not faithful to the Church's teaching, when they believe they can justify, as morally good, deliberate choices of kinds of behavior contrary to the commandments of the divine and natural law. These theories cannot claim to be grounded in the Catholic moral tradition. ... The faithful are obliged to acknowledge and respect the specific moral precepts declared and taught by the Church in the name of God, the Creator and Lord.
