This commandment demand respect for human life and is more accurately translated as " thou shalted not murder . " Indeed , killing may , under limited circumstances , be justified within Catholicism . 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 argue is philosophically opposed to the quality of life ethic , a philosophy which he characterize 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 assert 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 ; Arthur Caplan called this rhetoric " odiously wrong " . The Church is actively involved in the public debates over abortion , capital punishment and euthanasia , and encourage believers to support legislation and politicians it describe as pro @-@ life .