The phrase “sanctity-of-life” has played an important ideological role in public controversy about abortion and euthanasia in the United States of America. In 1984, President Ronald Reagan proclaimed January 22—the anniversary of the U.S. Supreme Court’s “Roe v. Wade” (1973) decisionFootnote 1—as the first “National Sanctity of Human Life Day.” Following Reagan, the proclamation was made annually by Republican Presidents George H.W. Bush and George W. Bush. It was not issued by Democratic President Bill Clinton and has not been issued by President Barack Obama. Since 1995, conservative members of Congress, including 2012 presidential candidate Ron Paul, have made several attempts to introduce a “Sanctity of Life Act” (2011) in order to establish rights of personhood for all human life beginning from conception.

As on the political battlefield, the phrase has also emerged as a key principle in contemporary Anglo-American bioethics, especially in the debates about end-of-life issues and abortion (Kohl 1974). According to George Khushf’s literature search (1996) it seems that Presbyterian preacher John Sutherland Bonnell was one of the first who started the phrase’s bioethical usage. In his plea against euthanasia, entitled “The Sanctity of Human Life” (1951 p 201) he contributed only a single sentence with the phrase: “Christianity has never ceased to emphasize the sanctity of human life and the value of the individual, even the humblest and lowliest, including the afflicted in mind and body.” Without explicating the phrase’s origin and its logic of argumentation Bonnell used it as a self-evident prohibition against killing innocent humans. Whether it may serve as a principle fundamental to the human right to life—like human dignity (Bayertz 1996)—has been doubted, not only because of its religious origin (Clouser 1973, Engelhardt 1996 p 203 ff.), but also because of the question of whether an absolute prohibition against killing can be regarded as adequate in the biomedical field of end-of-life questions (e.g. Fletcher 1951). Some decades later, philosopher and bioethicist Peter Singer (1994, 1999), and his colleague Helga Kuhse (1987) led the opposition against so-called “sanctity-of-life ethics” and predicted the rise of the new quality-of-life ethic with regard to questions of abortion and end-of-life decision-making. In response, the Roman Catholic theologian Donald Demarco has called Singer an “Architect of the Culture of Death” (2003).

Although the phrase “sanctity-of-life” plays an important role in both political and academic arenas, its meaning and origin is rather unclear. Neither analytical examinations (e.g. Clouser 1973, Frankena 1975) nor intense applied bioethical debates have brought a consensus. In this paper I offer a reconstruction of the history of the idea of “sanctity-of-life”. “Sanctity” is often misunderstood as an ontological feature of biological human life, which is confusing. Instead, the idea can be reconstructed in the sense of “sanctifying” one’s life by living it in a special spirit. Thus, the phrase denotes a mode of acting instead of an obscure property of physical life. If the historical reconstruction of this idea is convincing, I hope the ethical argumentation can proceed more fruitfully on that basis.

In sections 1 and 2 of the paper, I briefly examine paradigmatic modern theological and philosophical positions that struggle with the concept’s exact bioethical meaning. In section 3, I discuss how the concept’s Jewish and Christian conceptual history leads to the more general virtue-ethical concept of self-moralization found in Kant’s secular virtue ethics. Because Kant’s argumentation on suicide, especially in his Lectures on Ethics, plays a prominent role in the bioethical sanctity-of-life debate, I analyze this argumentation in more detail. In section 4, I examine Kantian ethics as an example that shows how the religious concept of sanctity-of-life can be fruitfully secularized and introduced into a secular ethical debate. Here I compare Kant’s model of secularization with Paul Ramsey and Ronald Dworkin’s translation of “sanctity” into ex- or intrinsic value. Finally, in section 5, I sketch out how and to what limited extent the concept of sanctity-of-life may contribute to a rights-based bioethical debate about end-of-life questions.

1 “Sanctity-of-life”—A Mysterious Concept in the Bioethical Debate

In his literature review, Khushf wondered why, although “both advocates and detractors designate ‘sanctity of life’ as an ancient principle of the Judeo-Christian and Hippocratic traditions”, they failed to cite any literature earlier than the twentieth century (Khushf 1996 p 294). He noticed that current writers use the term in ways that do not easily and directly map to earlier traditions he found in his literature search. At the same time the new “old” principle has been defined in the “New Dictionary of Medical Ethics” (1997 p 228) as follows: “This essentially religious concept has its basis in the notion that life is a gift from God. An additional factor within Christianity is the belief that humans are created in the image of God. In non-religious circles the term is used to indicate the utmost respect with which human life should be treated.” At a conference on “Sanctity of Life and Human Dignity,” in Bielefeld, Germany in October 1992, Catholic theologian and ethicist James Keenan, SJ sought to provide insight into the history and semantics of the sanctity-of-life principle, but had to admit “that the concept’s origin has not been recorded nor its development narrated […]. More surprising is the fact that we do not seem to know where the term came from, what its roots are, and why it has been appropriated elsewhere. Worse, this lack of knowledge becomes a particular asset for those who oppose the values that the concept purports to protect.” (Keenan 1996 pp 1–2) Thus Keenan assumed that the critics of the sanctity-of-life principle “create their own straw man”. With this in mind, Keenan has tried to counter those critical positions with a reconstruction of “sanctity as absolute inviolability” of physical human life based on the Catholic natural law tradition (Keenan 1997). As Keenan has observed, the meaning of sanctity as inviolability of physical human life is used especially in the writings of Pope John Paul II. (Keenan 1996 pp 3–4), and is also generally accepted by most of its theological (e.g. Ramsey 1968, Thomasma 1999) and philosophical (e.g. Frankena 1975, Dworkin 1993) defenders. Keenan has offered his interpretation despite the fact, as he has noted, that the term sanctity-of-life does not appear even “in the four most important modern documents from the Roman Catholic Church’s teachings on matters dealing with killing.” (Keenan 1996 p 4)

Like Keenan, many Christian (e.g. Fletcher 1951, Thomasma 1999 p 59f, Kopfensteiner 1999 p 202, Götz 2000 p 280) as well as Jewish (Green 1999 p 28, Kass 2002, Weingarten 2004, 2007) ethicists feel uneasy with the so-called “vitalistic”Footnote 2 smell of sanctity-of-life when used as a bioethical principle. “Vitalism” is the term they use to criticize ethically “naturalistic philosophy” that “assumes that physiological life is sacrosanct” (Fletcher 1951 p 206) or endows it with value in and from itself. Theologically speaking, they maintain: “Although life is indeed the gift of God, it is not merely a biological gift, and morally neutral.” (Weingarten 2007 p 333).

2 The Naturalistic “Straw Man” in the Bioethical Debate

One of the most influential philosophical critiques is delivered by Helga Kuhse in her book “The Sanctity-of-Life Doctrine in Medicine” (1987). She largely adopts the position of William Frankena (1975). In contrast to Fletcher (1951 p 206), Frankena claimed that wherever the sanctity-of-life principle is rooted, either in the Pythagorean background of the Hippocratic oath or in the Judeo-Christian tradition or elsewhere,Footnote 3 that it was Christian theology that made it especially influential. Kuhse follows Frankena’s conviction that the sanctity-of-life principle primarily aims at the protection of the bodily life of a human individual, but both struggle with the problem of so-called “vitalism” (Frankena 1975 p 44) and with “speciesism” (Kuhse 1987 pp 13–14, 210–212). Frankena carefully examined a variety of positions about respect for life: “absolute” (all life-shortening acts are morally wrong) and “qualified” forms (some life-shortening acts might be permissible, 1975 p 32), “direct” and “indirect” forms of respect for life for its own sake or for life as a condition for other good (1975 p 34), religious and moral foundations of the doctrine (p 31), “intrinsic” (valuable in and from itself) and “related” (valued by another, e.g. God) (p 40), “comprehensive” (all forms of life) and “non-comprehensive” (only human life) forms with regard to the extension, and so on. While Frankena recognized that all these forms can be held also by religiously-bound scholars, Kuhse determines that the theory of “the absolute prohibition of the intentional termination of life has its source in theology” (Kuhse 1987 p 15), but admits not being interested in the “specifically religious sense” (p 2) of the term. She defines the doctrine’s “absolute” formula as follows: “It is absolutely prohibited either intentionally to kill a patient or intentionally to let a patient die, and to base decisions relating to the prolongation or shortening of human life on considerations of its quality or kind.” (p 11) Then she argues that medical practitioners and also the Vatican’s Declaration of Euthanasia make implicit use of quality-of-life considerations and deny any difference between killing and letting die when proposing “to refrain from preventing death”. In consequence, says Kuhse, they do not assert the “absolute,” but only a “modified” type of the “sanctity-of-life doctrine” which leads, however, to its complete theoretical inconsistency. Thus the focus of her book questions the distinction between killing and letting die, and tries to show that the latter is an intentional act, which implicitly relies on quality-of-life judgments. Since her study on the “sanctity-of-life doctrine,” she has, with other bioethicists such as Peter Singer, promoted the program of “unsanctifying human life” (Kuhse 2001) in order to drop “the ‘sanctity-of-life’ doctrine and work out a quality-of-life ethic instead” (Kuhse 1987 p 220, see also Singer 1994, 1999)—a contradistinction which Warren Reich (1978 p 831) early critized as “a misleading dichotomy”.

Before examining sanctity-of-life versus quality-of-life with regard to end-of-life decision-making issues, it is necessary to understand how far the idea of sanctity-of-life is actually correctly determined to mean absolute inviolability of physical human life. To resolve some of this confusion, the meaning of the theological idea sanctity-of-life needs to be illuminated in order to get rid of naturalistic misunderstandings. Otherwise endless lamentations about the ”extreme vagueness of the sanctity-of-life doctrine” (Kuhse 1987 p 3, fn 3; already Clouser 1973 p 119) and fruitless “straw man”-debates will continue burdening bioethical considerations. Is there, then, a plausible non-naturalistic history of the idea of sanctity-of-life, and if so, is it of any importance for bioethical discussions?

3 The Non-naturalistic Theological Alternative

Frankena’s and Kuhse’s examinations share with most sanctity-of-life interpretations the focus on the element “life”. Here, we find many suggestions and speculations about what kind of life could be meant: merely biological, a body-mind unit, a more Cartesian-like life of pure mind or a biographical life (see the overview in Zimmermann-Acklin 2002 pp 165–173). Even authors who are dealing with the whole phrase (e.g. Clouser 1973; Engelhardt 1996), are not interested in a theological reconstruction of its meaning, since they find it inappropriate for pluralistic societies. But reconstructing the history of a religious idea in order to understand its original meaning is one thing; defending religious fundamental arguments is quite another one. Thus, I shall firstly take seriously the religious element “sanctity” in order to find out what sort of life could be meant in the expression sanctity-of-life. If this approach delivers a plausible reconstruction of the original meaning of the concept, we can, in a second step, look for reasonable possibilities to secularize the concept ‘within the limits of reason alone’ (Kant 1960).

3.1 The Jewish Foundations: Kiddush haShem Through Kiddush haChayim

Leon Kass, the Jewish scholar and former chairman of the President’s Council of Bioethics, gave decisive hints when wondering—like his Christian and secular colleagues: “What is it that makes what kind of life sacred? […], the phrase ‘sanctity of life’ does not occur either in the Hebrew Bible or in the New Testament. Life as such is not said to be holy (qadosh), as is, for example, the Sabbath. The Jewish people are said to be a holy people, and they are enjoined to be holy as God is holy.” (Kass 2002 p 235) Kass’s last sentence alludes to Lev 19:2: “Be holy, for I, the LORD, your God, am holy!”,Footnote 4 which Moses Maimonides holds not as a single commandment beside the others in the Jewish belief, but as the quintessence of all of them. Biblical exegetical analyses show a distinct use of grammatical modes of the Hebrew root “qds” (Kornfeld and Ringgren 1989; Lenzen 2002 pp 43–48).Footnote 5 Depending on whether it is referring to God, human beings or things, the grammatical conjugation of the Hebrew verbal root qds draws a clear distinction between modes of being and modes of acting. Only God can be qualified “holy” in the sense of an unalienable quality of being (qds niphal). And only God can make his people holy (qds hiphil), that is, enable his people to preserve their given sacredness through acting (qds hitpael) according to their elected relationship to God. With that, the precondition is given for praising God`s holy name through daily moral acts and therefore with the right attitude in liturgy as it is said in Lev 22:32: “do not profane my holy name; in the midst of the Israelites I, the LORD, must be held as sacred. It is I who made you sacred.”

The exegetical examination shows that only God Himself is intrinsically holy in the Hebrew Bible, that is, holy by Himself and permanently holy without any alteration. Creatures like humans receive their sacredness extrinsically from God. In contrast to God, creatures can lose their sacredness: non-human creatures through inadequate cultic use, human creatures because of acting inadequately. In consequence, there is an inner connection between preserving the received state of holiness through acting in a morally good way and praising God’s holy name, or—to express it in Jewish theological terminology: there is an inner relation between Kiddush HaChayim (sanctifying one’s own life) and Kiddush HaShem (‘sanctifying God’s Name’).

The following quotation shows that the strong connection between Kiddush HaShem, praising the Lord’s holy name, and Kiddush HaChayim, preserving the sacredness of one’s life, is still present in the Jewish community today. In 2006, Rabbi Joseph Telushkin published the first volume of his “Code of Jewish Ethics” entitled “You Shall be Holy”, in which he underlines three meanings of “Kiddush Hashem (‘sanctifying God’s Name’):

  • “A Jew should conduct his life in such a way that non-Jews will think, ‘If that is how Judaism causes Jews to act, then Judaism is a wonderful religion and Jews are good people.’

  • Non-observant Jews will witness the righteous behavior of religiously committed Jews and, as a result, be brought nearer to God and Judaism.

  • Jews should be willing to die as martyrs if oppressors try to coerce them to give up their faith.” (Telushkin 2006 p 456)

Leading a spiritually and morally blameless life is the prevailing idea over mere cultic observance and over the extreme possibility of martyrdom. Basically, Kiddush HaShem is an optimistic attitude to life, nourished by grateful trust in God, who wants his people to flourish in and with their earthly lives. Sacrificing one’s own physical life is only an extreme possibility of performing the Kiddush HaShem, only when a Jewish person is threatened by being cut off from the vivid source of her life—her faith in God. The concept of Kiddush HaShem through Kiddush HaChayim is not at all concerned with biomedical end-of-life questions—even the extreme case of martyrdom is no biomedical case—but a religiously based concept of the private moral conduct of life. Remarkably, Kiddush HaChayim’s theological background is not creation as is usually assumed (Ramsey 1968, BoH 1997, Zimmermann-Acklin 2002 p 174–187), but election. This is another significant clue that the sanctity in question is not a quasi “ontological” property of a being “inherited” through its divine origin, but a spiritual and moral quality of acting in responsibility towards God resulting from an interpersonal God-human relationship. Jewish scholars like the physician Michael A. Weingarten seem to be more sensitive to this aspect than contemporary Christian scholars when he states: “Holiness as a biblical concept is ascribed first and foremost to God and to His Name. In the Bible, man is adjured to become holy, in imitation of God in whose image he is formed. ‘Be holy, for I your Lord God am holy’ (Lev 19:2). The common Christian understanding of this is, that because God is holy, therefore Man, created in His image, is also holy. The Jewish understanding is different […]. Holiness, an attribute of God, is not to be identified automatically in those created in His image. Man’s holiness, then, is not so much a state as an achievement.” (Weingarten 2004 p 11) Therefore, Weingarten assumes that the misleading ontologizing interpretation of the “sanctity of life” should be critically reassessed as a “sanctification of life”.Footnote 6 In Hellenistic times this projected quality of acting was translated in terms of virtue ethics that expressed the right religious attitude towards God in one’s own actions.

3.2 The Christian Reception: “Be Holy!”

Since sanctity-of-life is widely accepted by Christian clinicians and lawyers as well as theologians, it has to be asked whether there is a Christian tradition of the concept that has kept its meaning in mind. There are clues of the concept’s Christian history up to its secularization in Kant’s Doctrine of Virtue. The most obvious Christian reception of the Jewish core doctrine Kiddusch HaShem was mediated by Jesus Christ himself when teaching his disciples the Lord’s prayer: “Hallowed be your name.” (Mt 6:9 // Lk 11:2) The concluding moral message of the interrelationship between Kiddush HaShem and Kiddush HaChayim and the illuminating transformation process of the relation between cult and morals can easily be demonstrated by the Christian reception of Lev 19:2 in the first letter of St. Peter, where we encounter again all aspects of the examination above: “Therefore, gird up the loins of your mind, live soberly, and set your hopes completely on the grace to be brought to you at the revelation of Jesus Christ. Like obedient children, do not act in compliance with the desires of your former ignorance but, as he who called you is holy, be holy yourselves in every aspect of your conduct, for it is written, ‘Be holy because I [am] holy.’” (1 Petr 1:13–16) 1 Petr 1:16 quotes from Lev 19:2 and makes an appeal for Christian conduct, like, e.g. Revelation 22:11, where Christians are admonished to keep their holy state of life. That is the background, still vivid in Jeremy Taylor’s 1667 book “The Great Exemplar of Sanctity and a Holy Life,” that Khushf (1996 p 296) cites and recognizes that this use of “sanctity-of-life” is at odds with the current bioethical use of the principle, since Jesus Christ is offered as the perfect example of the sanctity of his own life because of his perfect obedience to God’will. This motif of living a sanctified life, ideally fulfilled in Christ, can still be followed up to Immanuel Kant’s Religion Within the Limits of Reason Alone (1960 p 60, Ak 6:66): “The law says: ‘Be ye holy (in the conduct of your lives) even as your Father in Heaven is holy.’ This is the ideal of the Son of God which is set up before us as our model. But […] the act itself, of conforming our course of life to the holiness of the law, is impossible of execution in any given time.”

The idea of sanctity-of-life as a life lived in dedication to God can also be found in a special Catholic tradition. Here the term serves in a narrower sense as one of the four criteria by which church fathers and church teachers can be identified. Besides the right doctrine (doctrina orthodoxa), its long tradition or meaningfulness (antiquitas / doctrina eminens) and its acceptance by the church (approbatio Ecclesiae), we encounter the church fathers’ sanctitas vitae as the Latin origin of the term in question, which can be traced at least back to the 16th century (Feige 1997 p 435).

In contrast to the clerical Catholic tradition, the Reformed doctrine of sanctification underlined the unmerited “gift of the Holy Spirit”, that “continuously sanctifies” every Christian individual “(delivering us also from the power of sin), so enabling us to produce good works” (Coats 1921 p 182). Rejecting the Catholic liturgical understanding of sacrifice, the Reformed theologians pushed forward the moralizing of sacrifice in terms of the individual’s dedication of one’s life to God. John Calvin in particular developed his ethics in the 3rd book of his Institutio as the “tertius usus legis”, the third and most important use of the divine law besides the political and pedagogical. Based on Rom 12:1 and Lev 19:2, Calvin’s ethics are designed as a sanctification doctrine (Jacobs 1968 pp 103–107). Furthermore, Calvin’s doctrine of predestination signals the way by replacing the mechanical category of cause and effect with freedom’s category of reason and consequence in order to express the supernatural dependence of the human’s will when living a sanctified life from God’s gift of grace (Jacobs 1968 pp 109–111). With this change of categories, Calvin paved the way for Kant’s categories of freedom in the Critique of Practical Reason, which categorize human acts. Whereas Calvin showed that a sanctified human will is in perfect harmony with God’s will, Kant showed that a truly free human will is in accordance with the Categorical Imperative’s “ought”. With the last remarks we recognize one model of secularizing the Christian doctrine of sanctity-of-life: its moralization in the Kantian Ethics. Kant strived for this secularization since he was struggling with the problem of imputability of one’s deeds as did John Locke with his concept of person in the famous 27th chapter “On Identity” in his Essay Concerning Human Understanding.

This background explains why Kant significantly omits the religious foundation when citing Lev 19:2 via 1Petr 1:15–16: “Be holy!” in the secular Doctrine of Virtue (Kant 1996 6:446). Kant admonishes the moral subject to strive for moral perfectibility. However, it is no longer the commandment of God, but of “the purity (puritas moralis) of one’s disposition to duty, namely, in the law being itself alone the incentive, even without the admixture of aims derived from sensibility” (ibid). Consequently, Kant turns around the Calvinistic sanctification’s succession of grace and morally good human acting by making good moral acting a precondition for at least a reasonable hope of grace and beatitude.

3.3 Kant on Suicide and the Human Body as a Sanctuary

Kant’s argumentation about suicide in his Lectures on Ethics is often regarded as a candidate for the modern bioethical use of the term sanctity-of-life in end-of-life debates (Zimmermann-Acklin 2002 p 161, Cholbi 2008). Although the Lectures on Ethics are student’s notes, they allow interesting insight into Kant’s way of teaching. As in his Religion, he shows himself well acquainted with a religiously coined language and religious metaphors. While arguing about morally prohibited suicide, he uses the biblical language “something holy, that has been entrusted” to man. He also calls it “a thing inviolable” “in his own person” (1997 27:372). That fits well with Kant’s official secular argumentation against suicide in the Doctrine of Virtue § 6, where suicide is called the annihilation of the “subject of morality in one’s own person” and “debasing humanity in one’s person (homo noumenon), to which man (homo phaenomenon) was nevertheless entrusted for preservation” (1996 6:423). A little later in the given passage about suicide in the Lectures, Kant speaks about “life” that “has been entrusted” to man and that suicide would “violate the sacred trust assigned to him” (1997 27:372).Footnote 7 But when quarreling with the Stoic’s defense of suicide, Kant underlines that he disagrees not because physical life were valuable in itself. For Kant, the reason is that physical life is a necessary condition for a human moral subject to conduct a moral life (1997 27:371). So bodily life is a means, moral life the end.

In St. Paul’s reference to the body as “a temple of the holy Spirit within you, whom you have from God” (1 Corinthians 6:19) Kant could have found support for calling bodily life a “sanctuary”, although he does not explicitly refer to that biblical text. Nevertheless, “the holy” “humanity” which “has an inviolability in his person” corresponds with St. Paul’s “the holy Spirit within you”. That again corresponds easily with the passage in the Critique of Practical Reason (1993 5:131–132) suggested by Zimmermann-Acklin (2002) to elucidate the ‘life as a sanctuary’ passage in Kant’s Lectures on Ethics, “[…] that humanity in our person must itself be holy to us, because man is subject to the moral law and therefore subject to that which is of itself holy, and it is only on account of this and in agreement with this that anything can be called holy.” These sentences perfectly illustrate how the moral law replaces God’s spirit in Kant’s secular ethics. For Kant, the moral law is therefore the only entity “which is of itself holy.” Everything’ else receives its kinds of holiness by following the moral law, as in religious ethics fulfilling God’s will. Physical human life serves as a sanctuary—a temple in St. Paul’s words—because the claim of the moral law is embodied in the human being as the consciousness of the (idea of) humanity or homo noumenon.

4 Two Ways of Translating Sanctity-of-life

4.1 Secularization as Self-moralization: Immanuel Kant’s Model of Internalization

What results can be drawn from Kant’s engagement with the sanctity-of-life tradition? Kant’s conceiving bodily human life as a sanctuary contains three interesting aspects: first, that Kant does not defend a biologically based ethical naturalism, since physical life is not characterized as intrinsically holy, but projected only as the fundamental natural condition for conducting a moral life. As such, physical life participates in the inviolability of the moral integrity of the agent who is dedicated to fulfill the “intrinsic” “holy” moral law. Therefore, Kant can even deliver casuistic reflections upon the ultimate possibility of morally justified self-killing acts if morally higher values could be realized. But dealing with self-sacrifice as a kind of “moral martyrdom” only in the context of duties to oneself underlines that this can never be a duty demanded by others. That leads to a second, often neglected aspect:

Duties to oneself are not addressed in the Doctrine of Right, only in the Doctrine of Virtue. That is meaningful because the Doctrine of Right refers only to interpersonal duties, not to intrapersonal duties. In § 6 Doctrine of Virtue, Kant explicitly refrains from dealing with suicide “as a violation of one’s duty to other people” (1996 6:422) like spouses, children or fellow citizens, which may be possible reasons in a normative ethical or in a juridical debate. But looking at one’s physical life as a “sanctuary” is restricted to the subject’s moral self-relationship, that is, to the moral first-person perspective. Although duties to oneself have objective moral validity for Kant, it is their nature that they cannot be prescribed by another person or judged from an external position. Only the moral agent oneself can and shall take these duties into account by recognizing and constituting oneself as a moral subject. Realizing this inner act of recognition of one’s own responsibility makes the moral subject irreplaceable. With that, Kant confidently transfers the biblical sanctity-of-life concept into a secular virtue-ethical self-relationship between the empirical person (homo phaenomenon) and the ideal moral personality (homo noumenon).

Finally, the understanding of human bodily life as an instrument for leading a moral life is not only significant with regard to physical self-preservation and therefore to end-of-life situations. In addition, the duty to self-preservation considers life as the basic good that enables leading a moral life in general in the full range of the basic motif: praising God through living a holy life (Kiddush haShem through Kiddush haChayim). The question of suicide is therefore only the extreme point, where the moral question of how to live a life emerges. Thus, reducing the sanctity of human life to mortal questions fundamentally impoverishes its meaning.

These observations drawn from the suicide issue fit Kant’s secularized demand to strive for moral self-perfection by purifying one’s own moral motivation regarding life conduct: “Be holy”. Moral motivation is not accessible for external moral judgment for two reasons: Epistemologically, somebody`s purity of motivation cannot be referred to, because it is not an empirical object of knowing; morally, it must not be addressed, since this would be inconsistent with the duty of respecting another human being’s moral sovereignty. In Kant’s virtue-ethical maxim, merely “one’s own [natural and moral] perfection”, and only “the happiness of others” are demanded, and not vice versa (see Kant 1996 6:387–394). So the first-person perspective exemplifies the fact that sanctity-of-life is not an empirical feature of another physical or mental or biographical life, but a sanctifying moral way of living that questions no one but oneself.

Hence, the theological history of the idea of sanctity-of-life already offers a model of its secularization through internalization by Kant. Kant adopts the commandment from Lev 19:2 as a call for moral self-perfection, but drops the theological foundation. With that, he replaces the God-human relationship with the relation the moral agent as a homo phaenomenon has to her own consciousness as the homo noumenon, in which the moral law’s claim is present as a fact of reason. That is how the external interpersonal relation between God and the human being is turned into the internal or intrapersonal relation of the human moral agent herself—a process described as the secularization of human moral consciousness by Kant (Kittsteiner 1995). “Be holy!” can only work as a call for moral self-perfection under the precondition of an intrapersonal relationship of the moral self whose theoretical structure Kant develops in the Doctrine of Virtue § 3 (1996 6:418) when scrutinizing how duties to oneself could be possible. Since it is not logically impossible to think of ourselves this way, the human being can be thought of as having the unique ability to put oneself under obligation. Therefore, being human means not only being alive, but being able to conduct a moral life and take responsibility. According to Kant (1996 6:417–418), the internal possibility of self-obligation is the necessary precondition for the possibility of any external obligation towards others. Obligations to others presuppose self-obligation.

Insofar as moral self-perfection strives for the purity of motivation, it is only the moral agent herself who can “sanctify” her moral life through the purification of her moral motivation. How much the agent succeeds in her own “sanctification” can, therefore, not be judged from an external third-person’s perspective, but only through internal self-examination. So, internalization serves as a way of secularizing the concept sanctity-of-life as a concept of moral self-evaluation of one’s deeds.

4.2 On Extrinsic and Intrinsic Values—Theological and Secular Ways of Externalization

In his influential article about “The Morality of Abortion” (1968) the Protestant theologian Paul Ramsey claimed that “from an authentic religious point of view” (p 70) any sanctity or dignity of the life of human beings derives from God and not from biological processes or from any social or political order. While maintaining that a “life’s sanctity consists not in its worth to anybody” (p 72), Ramsey rejected the idea that any human being’s value could become dependent on contingent processes of valuing. Speaking positively, Ramsey’s defense of the divine origin of human’s sacredness is a defense of the inalienability of human dignity and the inalienable, pre-positive right to life (p 74). When, on the other hand, Ramsey claims that human dignity is “’an alien dignity,’ an evaluation that is not of him but placed upon him by the divine decree” (pp 73–74), there is no contradiction; instead, here he focuses on refuting the concept of an intrinsic biological or natural value of human life and its “vitalistic” interpretation, because human life receives its value externally from God. So far, Ramsey’s theological argumentation for the divine origin of human dignity or human life’s sacredness is consistent with our reconstruction of the sanctity-of-life.

However, since Ramsey was especially interested in human life’s value as an argument against abortion, he interpreted the sanctity doctrine from an ontologized creational theological perspective. In this perspective “sanctity” or the dignity of being in the image of God become ontological features in which the human creature participates as the holy Creator’s handiwork. Ramsey did not clearly exclude that ontological understanding when dealing with God as “the origin of a human life”, which should be handled “as a divine loan” (Ramsey 1968 pp 74–75).

The creational ontologizing perspective, which is often taken by Christian theologians (see 3.1), has misleadingly given way to a secular view of life-as-a-donation bestowed from outside the agent, instead of a view of the moral quality of the agent’s internally-generated attitude and life conduct. Therefore Ramsey’s argumentation suggests a kind of theological naturalization from an external third-person perspective—a quasi ‘objective’ view on somebody’s life as if seen by God. The claim that human life has ‘objective’ religious value provokes criticism, because agnostics or atheists do not share the religious foundation. Logically, the concept’s theological meaning and moral content vanishes proportionally with a vanishing belief in the existence of the Creator. Finally, when this source of value is rejected, the question remains: “What’s Special About Human Life?” (Kuhse 1987 p 211, similar Singer 2005 p 83) This question is raised more pointedly, the more the background of an interpersonal God-human relational moral metaphysics is replaced by a scientific, naturalistic background in which “human” is defined as homo sapiens rather than as a moral agent who is capable of (self-)obligation.

Hence, we have to analyze whether the intuition of a certain inalienable value of human life might be conceived with an elaborated concept of “intrinsic value” that avoids a naïve fact-value fallacy. Such a paradigm can be found in Ronald Dworkin’s chapter “What is sacred?” in his book “Life’s Dominion” (1993). There he refers to a concept of sanctity-of-life as an intuition that human life should not be wasted. He uses it as a religious equivalent for the secular idea of inviolability of human life (1993 p 25, p 73) and subsumes it under the concept of an “intrinsic value”. According to Dworkin, the idea of sanctity-of-life applies also to human entities like fetuses, which he does not regard as persons with interests or rights (see pp 68–69; similar already Clouser 1973). He assumes “that conservatives and liberals all accept that in principle human life is inviolable in the sense […], that any abortion involves a waste of human life and is therefore, in itself, a bad thing to happen, a shame” (1993 p 84), an “insult to the sanctity of life” (p 86). Referring to economic terminology, Dworkin holds that conservatives rank “divine or natural investments” higher, in contrast to liberals, for whom the frustration of “human investments” has more gravity (1993 p 91). With the help of these assumptions, Dworkin tries to explain the gap between the parties within the public abortion debate despite the fact that almost all of them were equally convinced of the sanctity-of-life. Since he is not interested in the meaning and origin of the concept itself, he is not concerned with the problem of so-called “vitalism” with regard to the conservative opinion of natural investments.

When Dworkin calls the sanctity-of-life an “intrinsic value” he distinguishes it from “instrumental” values (the usefulness for something else) and from “subjective” or “personal” values, which are of value for an individual. According to Dworkin, “intrinsic value” means “what we value only once it already exists” (1993 pp 71–73). Within the framework of Dworkin’s investment theory, Ramsey or Frankena would call that argumentation an extrinsic value concept, because human life is bestowed with value by other humans who evaluate a certain “creative process” (1993 p 78)—a divine, natural, or a human engagement—as a valuable investment. Dworkin leaves the concept of sanctity-of-life evaluatively vague since he uses it for some human entities, which are, in his eyes, not persons with rights. He designs sanctity-of-life as a concept that ascribes value to other human physical lives from an external point of view. The criterion of evaluation is the economic grade of investment instead of the moral grade of moral self-perfection. Thus, Dworkin’s “intrinsic value” theory is, like Frankena’s and Kuhse’s secular extrinsic value theory and like Ramsey’s extrinsic creational value theology, another example of ontologizing the “sanctity” to an externally received feature of biological human life, but without bestowing all human beings with a right to life.

5 A (Bio-)Ethical Outlook: What is Sanctity-of-life Useful for?

Finally, what is the outcome of the examination of the history of the idea of sanctity-of-life—bioethically and ethically? What purpose does it serve and what purpose should it not be asked to serve?

First, we see that for a variety of bioethicists, secular or religiously bound, liberals or conservatives, the sanctity-of-life concept disappoints with regard to end-of-life decisions. It delivers no criterion and no norm with which to decide upon euthanasia issues. One reason for this, I have argued, is that it does not relate to the physical conditions of human life, but rather to the agent’s own moral attitudes and the virtue-ethical quality of acting. The fact that the concept is met with wrong expectations makes it understandable that many bioethicists find the term ‘sanctity of life’ more confusing than clarifying and seek to replace it by ‘value of life’.

Second, although it touches peripherally the problem of the moral justification of suicide, the sanctity-of-life idea should not be reduced to functioning as a bioethical principle. Arguments might perhaps indirectly be drawn from the sanctity-of-life motif for reflections on the moral justification of (assisted) suicide in biomedical contexts, but these ethical deliberations do not derive solely from a so-called sanctity-of-life principle. Normative bioethical argumentation about (assisted) suicide has to consider more than the isolated and perhaps academic question of whether there might be ethically justified cases of really free suicidal acts. With regard to end-of-life care, research in hospice ethics and palliative care ethics has shown that it is absolutely necessary to establish excellent supportive and patient-centered care for terminally ill and dying people to help ensure that the quality of care they are missing does not lead to a patient’s desire for (assisted) suicide.

Third, the sanctity-of-life is not a doctrine of the basic human right to life, since it is a virtue-ethical concept and not a rights concept. Sanctity-of-life does not simply refer to a value of biological existence, but to a spiritual and virtue-ethical way of how to use one’s own physical existence. Hence, it is not a claim about other persons, but only a claim about one’s self. The rights-perspective is an interpersonal issue, sanctity-of-life in its secular form, however, denotes a virtue-ethical intrapersonal relationship. This insight, drawn from the concept’s history, opens a more fruitful avenue for ethical reflections on questions of self-responsibility, moral autonomy, self-reliance, truthfulness as well as further considerations on moral agency, moral attitudes and virtue-ethical issues which are often overlooked in bioethics. The old biblical, Jewish and Christian concept of sanctity-of-life, which we recovered in Kant’s virtue-ethical imperative “Be holy!”—that is: Strive for increasing truthfulness in your acts and decisions and bear the responsibility for what you are doing and willing!—cannot and must not replace normative ethical deliberations or a rights-based ethic. But it may be a keystone in the process “Toward a Virtue-Based Normative Ethics for the Health Profession” (Pellegrino 2001 p 113) and a necessary element in an ethic of “response-ibility” that completes a “rights-based morality” (Tauber 2011). From this perspective, the idea of sanctity-of-life is an ethically useful concept.