Fifth commandment

"You shall not kill."

This commandment demands respect for human life. Jesus expanded it to prohibit unjust anger, hatred and vengeance, and to require Christians to love their enemies. The basis of all Catholic teaching about the fifth commandment is the sanctity of life ethic, which Kreeft argues is philosophically opposed to the quality of life ethic, a philosophy which he characterizes as introduced by a book entitled Die Freigabe der Vernichtung des Lebensunwerten Lebens (The Permission to Destroy Life Unworthy of Life) (see Life unworthy of life) and which he asserts was the "first to win public acceptance ... by German doctors before World War II—the basis and beginning of Nazi medical practices."This interpretation is supported by modern medical journals that discuss the dilemma posed by these opposing philosophies to physicians who must make life or death decisions. Some bioethicists characterize the use of the "Nazi analogy" as inappropriate when applied to quality of life decisions; some call this rhetoric "odiously wrong".The Church is actively involved in the public debates over abortion, capital punishment and euthanasia, and encourages believers to support pro-life legislation and politicians.