The Right to Life is, in a sense, the most Fundamental and Basic Absolute Natural Right (Urgrundrecht)
The right to life is not only a natural and an “absolute right,” as also the right to the freedom of religion or the right to choose one’s wife freely upon her consent, but it is also an, or even in a certain sense the, absolutely foundational concrete human right (Urgrundrecht). This does not exclude that other fundamental human rights, rooted in the dignity of the awakened actual conscious life, have another kind of priority and more specifically “personal character” precisely because they exist only on the level and dignity of the rational conscious life of the human person.
That nonetheless the right to life is in a certain sense the most foundational and fundamental one, one can see through the following reflection: all other human rights presuppose necessarily human life and human existence while the right to life itself has, among the concrete human rights, no more fundamental foundation in other rights of the human person but constitutes rather their ground. Of course, it belongs to human persons in virtue of not just having plant or animal life but of being a living being of rational nature, a living person endowed with the dignity that pertains to it, which is the foundation or other more universal human rights that make a valid claim (founded on this universality of theirs) to being the Urgrundrecht.
Thus also the right to life has its root in the nature, existence and dignity of human life. Hence it could be considered to have itself a more abstract and universal root that is the common root of all natural and fundamental human rights: in the right to have one’s personal dignity respected, which could be regarded as the most universal basic human right. Thus logically speaking, and covering all levels of human dignity and the root of the human rights grounded in them, the most universal formulation of the Urgrundrecht, in which all the concrete rights, such as the right to life, the right to freedom, the habeas corpus and all other basic human rights have their root, is the right to be respected in all rights that pertain to human dignity.
We could still distinguish two senses of this right: (1) one that is most general, as just formulated, and comprises the right to life, (2) the other one being more restricted to a certain manner of adequately being treated as a human being that refers to a more limited set of acts and attitudes of being “treated with dignity” that does not include the respect for the right to life but reaches from sheer rules of politeness to countless forms of respectful dealing with human beings.
Art. 1 GG (Grundgesetz) of the German Basic Law states that the respect of human dignity is the highest obligation of the entire activity of the state and thus implicitly the claim to be treated in ways that correspond to human dignity is considered by the Grundgesetz to be the Urgrundrecht that has not been created through the Basic Human Rights Catalogue, but is considered by it to be part of a pregiven and trans-positive order of rights. Immediately after the judgment that the respect of human dignity is the highest obligation of the state, the GG formulates the right to free unfolding of one’s personality and the right to life as the two most fundamental concrete basic human rights. But as the right to free unfolding of one’s personality presupposes that one lives, the right to life can be considered to be the most basic concrete human right.
We cannot see, as the earlier Martin Kriele, such an absolutely foundational human right in the habeas corpus, or with Kant, in the right to freedom, or with Jellinek, in the right to religious freedom, however important these rights are in themselves and in the history of human rights and are, as we shall see, an Urgrundrecht in a third sense, but rather either in the right to life or in a more abstractly conceived right that grounds all other human rights including the right to life, such as the right not to be harmed in one’s basic rights, as Hugo Grotius held.
For in the first place, any right to freedom, habeas corpus as well as any other right presuppose the right to life because they would come to naught without it.
Secondly, a right to freedom just as the “habeas corpus” right (which only refers to a small portion of the rights to freedom and forbids to incarcerate and to hold a prisoner without due process), unlike the right to life that all human beings without exception possess, apply only to a small sector of human persons, for example not to small babies or comatose patients, and can under circumstances of emergency or national peril be temporarily suspended.
Thirdly, these rights exist only on the level of the second dimension and source of human dignity, the dignity of an awakened human person, and even only of a conscious person of a certain maturity. (Babies and small children do not have the habeas corpus right and also their “right to freedom as long as they do not infringe on other persons’ rights” only comes to actual existence and application as they grow up; likewise, their “right to freedom from any other will imposing any necessity on them“ (Kant) is non-existent or at least purely potential in the not yet or no longer rationally conscious agent; how could a baby that has to be fed and diapered or a comatose patient have this kind of right to freedom and independence? It is even very limited until children come of age, and therefore it is not true to claim with Kant that the right to freedom is the only original right a person possesses in virtue of his humanity. It is not a right that man possesses in virtue of his humanity but only in virtue of his conscious and mature awakened being, and even then it may be questioned, and was for centuries questioned, whether every human person in every class and sector of society and regardless of all previous commitments and bonds entered by his or her parents, possesses this right to freedom and unbounded autonomy. Even any standing under parental, military, or other authority restricts this right. In contrast, the right to life (as likewise that of not being just treated as a means, that Kant himself so clearly formulates in one of his personalist formulations of the first categorical moral imperative, or the right not to be sexually abused, mutilated, intentionally infected with diseases, etc.), and the right not to be treated unworthily of a human person are truly rights of every human person from conception to natural death, and are fully grounded in the ontological dignity of a person, i.e. of a substance of rational nature and thus can be regarded as the most basic human rights and, inasmuch as human life is the very existence of a human person, the right to life can be regarded as the most basic of all basic human rights.
Of course, there is a sense in which those rights that are grounded in the actualized lived personal existence, fulfill the idea of rights more fully inasmuch as a legal claim to something, a right, seems to make full sense only when we are faced with a consciously awakened person and not when we deal with unconscious subjects of rational nature like the unborn who are not yet awakened fully consciously to their personhood. In this respect those mentioned rights that are rooted in conscious rational life of persons, such as the “right to freedom” so much emphasized by Kant, or the “right to religious freedom” regarded by Jellinek as the most basic human right seem to have an advantage as candidates for being the most basic human right (Urgrundrecht) because they entail the experienced and fully personal claim to some goods. But quite apart from the fact that also the right to life does not only belong to the unconscious persons of embryos and comatose patients but also to awakened human beings who experience this right as a most basic one, it seems that it is in a sense the most basic one inasmuch as all other human rights presuppose it and also because it is, while fully belonging to the rational conscious state of the person, precisely inalienable and not dependent on it.
 See also Josef Seifert, Sein und Wesen (Heidelberg: Universitätsverlag C. Winter, 1996); the same author a less developed version of this work, “Essence and Existence. A New Foundation of Classical Metaphysics on the Basis of ‘Phenomenological Realism,’ and a Critical Investigation of ‘Existentialist Thomism’,” Aletheia I (1977), pp. 17-157; I,2 (1977), pp. 371-459.
 In the German GG art 1, in which the distinction between moral obligations and legal obligations to respect human rights is not clearly drawn, this right is not explicitly formulated but only the obligation to protect human life.
 Art 1
(1) Die Würde des Menschen ist unantastbar. Sie zu achten und zu schützen ist Verpflichtung aller staatlichen Gewalt.
(2) Das Deutsche Volk bekennt sich darum zu unverletzlichen und unveräußerlichen Menschenrechten als Grundlage jeder menschlichen Gemeinschaft, des Friedens und der Gerechtigkeit in der Welt.
(3) Die nachfolgenden Grundrechte binden Gesetzgebung, vollziehende Gewalt und Rechtsprechung als unmittelbar geltendes Recht
 Art 2
(1) Jeder hat das Recht auf die freie Entfaltung seiner Persönlichkeit, soweit er nicht die Rechte anderer verletzt und nicht gegen die verfassungsmäßige Ordnung oder das Sittengesetz verstößt.
(2) Jeder hat das Recht auf Leben und körperliche Unversehrtheit. Die Freiheit der Person ist unverletzlich. In diese Rechte darf nur auf Grund eines Gesetzes eingegriffen werden
 Cf. Wolfgang Waldstein, Das Menschenrecht zum Leben. Beiträge zu Fragen des Schutzes menschlichen Lebens, (Berlin: Duncker & Humblot, 1982.
 Immanuel Kant, Metaphysik der Sitten, Kants Werke, Akademie‑Textausgabe (Berlin: Walter de Gruyter & Co., 1968), Bd. VI, AA 06 229 ff.; 231 ff.; 237 f.:
VI237 Freiheit (Unabhängigkeit von eines Anderen nöthigender Willkür), sofern sie mit jedes Anderen Freiheit nach einem allgemeinen Gesetz zusammen bestehen kann, ist dieses einzige, ursprüngliche, jedem Menschen kraft seiner Menschheit zustehende Recht, …
 Martin Kriele puts in his earlier writings a special emphasis on the „habeas corpus-Grundrecht,” and declares the „habeas corpus” as source and real origin of human rights, See Martin Kriele, Recht Vernunft Wirklichkeit (Berlin: Duncker & Humblot, 1990), „Habeas Corpus als Urgrundrecht“, pp. 79 ff.; see also ibid., pp. 71-235. He corrected and limited this thesis in his later article on „Freiheit und Befreiung.” See Martin Kriele, „Freiheit und ‘Befreiung’: Zur Rangordnung der Menschenrechte“ (1988), in: Martin Kriele, Recht Vernunft Wirklichkeit (Berlin: Duncker & Humblot, 1990), S. 204-235. There he counts the habeas corpus among the most insignificant group of human rights which can be suspended, not being immune to emergency states (they are not „notstandsfest”). Secondly, he points out that the violation of these rights cannot count under all circumstances as „grave violation.” See also Josef Seifert, „Die vierfache Quelle der Menschenwürde als Fundament der Menschenrechte”, in: Burkhardt Ziemske (Hrsg.), Staatsphilosophie und Rechtspolitik. Festschrift für Martin Kriele zum 65. Geburtstag (München: Verlag C.H. Beck, 1997), S. 165-185.
8. Already Hippocrates formulated the principle “primum non nocere”. See Hugo Grotius, who lists in his de imperio summarum potestatum circa sacra. Critical edition with introduction, english translation and commentary by Harm-Jan van Dam, volume I. Studies in the history of Christian Thought (Leiden: brill,2001), p. 328. The following basic human rights, rather as basic natural obligations: “priore modo [as natural law/right without any human action: “absolute non obstante quocumque facto humano”] naturale est deum vereri, amare parentes, innocenti non nocere. ...”
 As also Kriele points out in a later article. See Martin Kriele, Recht Vernunft Wirklichkeit (Berlin: Duncker & Humblot, 1990), pp. 71-235, especially ibid., „Freiheit und ‘Befreiung’: Zur Rangordnung der Menschenrechte” (1988), in: Martin Kriele, Recht Vernunft Wirklichkeit (Berlin: Duncker & Humblot, 1990), pp. 205 ff., where he distinguishes thee levels of human rights: tot he weightiest and most fundamental ones correspond „grave violations” such that international responses are required (such as genocide, enslavement); the second layer would be „notstandsfeste Bürgerrechte”, human rights which also apply in cases of states of emergency (such as not to be tortured and arbitrarily killed, discriminated because of race, gender, religion, or social background, freedom of conscience and religion, etc.) Finally there are other civil rights such as the habeas corpus (against arbitrary incarceration), the right to be heard by independent judges, the rights of prisoners, foreigners, minorities, etc., which can be suspended under certain circumstances.
 A right to „Freiheit (Unabhängigkeit von eines Anderen nöthigender Willkür), sofern sie mit jedes Anderen Freiheit nach einem allgemeinen Gesetz zusammen bestehen kann,” as Kant calls it. See Immanuel Kant, Grundlegung zur Metaphysik der Sitten, Kants Werke, Akademie‑Textausgabe (Berlin: Walter de Gruyter & Co., 1968), Bd. IV VI237.
 “ist dieses einzige, ursprüngliche, jedem Menschen kraft seiner Menschheit zustehende Recht”.
 See our explanation of personhood and personal dignity in Josef Seifert, The Philosophical Diseases of Medicine and Their Cure, ch. 2.
 Some authors regard the freedom of religion as Urgrundrecht. In possibly the first explicit declaration of human rights, the Bill of Rights of Virginia (1776), art. 16 this right is explicitly guaranteed, as well as in art. 10 of the French Déclaration des Droits de l’Homme (1789). In the American Bill of Rights (1791), in the First Amendment it ist he first one mentioned among a list of basic human rights. According to Georg Jellinek it ist he „Urgrundrecht.“ See Georg Jellinek, Die Erklärung der Menschen-und Bürgerrechte (Leipzig: Duncker and Humblot, 1895/1904), (Heidelberg, 1996), pp. 18 and 90.