This paper is a survey of Hippocrates and the presence of his principal clinical-medical, philosophical-medical, and ethical ideas and beliefs in the documents of the Church and in works of theology. It therefore carries on from the study already conducted into references to Hippocrates in papal documents, works which have already been published. ,  In this paper I will dwell upon those passages in the speeches and addresses of popes Pius XII, Paul VI, John Paul I and John Paul II which emphasize th e ethical importance of this famous physician of ancient Greece.
This collection of quotations and citations is not an exercise in medical history which aims at creating a collection of documents. Nor is it an attempt to engage in a kind of literary history. It is, rather, a collection of ethical observations and guidelines which are to be found in surviving ancient Greek texts and which correspond in certain ways and forms with Christian ideas and beliefs.
We can safely state that during the grea t periods of the history of Western civilization there have always been examples of the influence of the ideas and ethical principles of Hippocrates.
At the time of early Christianity, the essentially Christian basis and character of central Hellenic ideas was demonstrated by the fact that in the preamble to the Hippocratic oath the introductory words "Apollo soter" came to be replaced by the phrase "Christus medicus."
The doctrine of Hippocrates could easily be transplanted into the patristic and scholastic traditions because it well corresponded to the integral and personalist ideas of Christianity and because of the authority of "Christus medicus," the phrase the doctor employed to swear to uphold the ethics of the medical profession.
This broad-ranging subject can only be dealt with here by analyzing key moments. Indeed, the research which lies behind this paper perhaps indicates that an overall and general picture may well not be possible.
There are also various other questions which mu st be addressed, and most specifically the actual authenticity of the ideas which are propounded in the works attributed to Hippocrates and of the texts which constitute the Corpus.
1. Hippocrates in Papal Documents
In the works of Petrus Hispanus, a medical doctor with academic qualifications who then became the doctor to Pope John XXI, we can find two comments on Hippocrates  namely De Regimine Auctorum and Prognostica.
In our times, and more precisely in 1954, Pope Pius XII defined the medical-ethical significance and meaning of the works of Hippocrates in the following way:
"The works of Hippocrates are without doubt the noblest expression of a professional conscience which above all else calls for respect for life and self-sacrifice in relation to sick people and also pays attention to personal factors: self- control, dignity, reserve. He knew how to present moral norms and to integrate them into a broad and harmonious program of study, and he th us gave a present to civilization which was more even more magnificent than that made by those who built empires." 
Pope Paul VI had similar observations to make and sought to warn doctors about the dangers which were inherent in the advances in medical science:
"It is clear that these new inventions should not in any way prejudice the exercise of a medical ideal which has guided medicine for millennia and has been expressed in a tradition based the oath of Hippocrates, a figure who was a defend er of life. A pollution of this cardinal principle would involve a fatal step backwards which would have disastrous consequences. This is something which you will be aware of more than any other category." 
Under the title of "The Illustrious," Pope John Paul I wrote a number of imaginary letters to important historical figures, one of whom was Hippocrates-" a contemporary of Socrates and like him a philosopher." Pope John Paul I called the Greek physician:
"The author of a famous oath...of an e thical code of unending worth. Doctors swear by this oath to prescribe suitable treatment for their patients and to protect them from injustice and above all else from what is harmful. They solemnly promise to never induce an abortion; they undertake to go to a home solely in order to treat sick people and promise that they will not take bribes. In addition, they swear to uphold the sacredness of the professional secret." 
With this list of ethical-medical undertakings and promises Pope John Paul I blessed the incorporation of the ancient Greek code of professional conduct into the outlook and approach of the Christian medical doctor.
As early as 1978 John Paul II referred to Hippocratic ethics during a reception for the Association of Italian Catholic Doctors. He warned those present against the dangers of using medicines and drugs which "not only contradict Christian ethics but every form of natural ethics and which are in open contradiction with those professional duties expressed in the famo us oath of the ancient pagan doctor." 
In his address to the members of the General Assembly of the World Union of Doctors John Paul II, when discussing the question of genetic engineering and its capacity to reduce the human being to an object, proffered the following injunction: "Let all medical doctors be faithful to the Hippocratic oath which they take when they graduate."  During his speech to the members of the International Congress on the Humanization of Medicine held in 1987 John Paul II spoke about the need for men to be aware of their true duties in the exercise of their profession: "You should be deeply convinced of this truth because of a long tradition which goes back to the intuitions of Hippocrates himself."  And when nominating the members of the Pontifical Academy for Life John Paul II made an explicit reference to Hippocrates when he spoke about the need to "carry on the Hippocratic tradition." 
On November 26, 1994 Pope John Paul II referred again to Hippocrates when he spoke about a Vatican codex which contains the Hippocratic oath transcribed in the form of a cross, the symbol of the Christian understanding of human nature, of holiness, and of the mystery of human life. 
Under the unifying influence of the model of Christus medicus, Hellenistic naturalism and Semitic personalism were fused together in early Christianity, and this was a direct result of a new diagnostic approach to the origins and causes of illness. Without doubt it is to Hippocratic t hought that we must attribute the move towards a sense of ethical responsibility which in turn gave rise to the creation of medical oaths which had preambles with a monotheistic character and conclusions with explicit reference to a transcendental reality, to God, before whom such oaths was sworn. 
2. Hippocrates in the Patristic and Scholastic Traditions
During the patristic age there was an abundance of quotations from the authentic works of Hippocrates and from the Corpus, and these have survived to us. Indeed, Cyprian of Carthage, Gregory Nazianzen, Gregory of Nyssa, and Eusebius of Cesarea all held to a theory of the natural sciences about the origins and causes of illness which went back to Hippocrates. However there were also magical and demoniacal theories.
It should also be observed that Eusebius makes repeated reference to Hippocrates in a chapter on the theory of illness, in reflection upon free will, and knew the ancient Greek's theory of diet. He was also familiar with the motto: "nature is the best physician." Eusebius also invokes Hippocrates when stressing the importance of prognosis and in expounding the idea that the soul is of primary importance in the relationship between the body and the soul , . In discussing the Patristic tradition reference should also be made to the ethical-medical chapters of the Didaché of the first century after Christ: you must not induce the abortion of a child and you must not kill a newly-born baby. 
Research into Hildegard of Bingen (1098-1179) has drawn a blank as far as references to Hippocrates are concerned. Heinrich Schipperges writes:
"Hildegard of Bingen does not offer an explicit theory in this matter. He does not repeat the oath of Hippocrates and he does not speak about medical ethics. We do no t find direct references to the goals of health care and no methods are offered in relation to caring for the sick person. There is nothing which offers instruction and nothing of a dogmatic character which could give rise to a theory on duties and their categorization. However his works are a contribution to Medieval deontology and are all the more valuable because such works were absent at the time. But because they are often not presented in a serious way they cannot be considered seriously." 
H onorius Augustodunensis, who died after 1150, wrote the following of Hippocrates: "per medelam corporum deducit ad medelam animarum." 
Knowledge about Hippocrates and about the Corpus was kept and handed down by Nestorian-Syrian Christianity. This branch of Christianity dedicated space in its schools and monasteries to the conservation and transmission of philosophical and scientific learning, and gave especial room to the Aristotelian part of this inheritance: not only Aristotle him self but also Euclides, Hippocrates, Galenus and Archimedes. The philosophical, mathematical and medical works of these authors were first translated from Greek into Syriac and then into Arabic.  The concept of "potentia" can be attributed to the Greek concept of "dynamis" which is also to be found in the Corpus Hippocraticum where it is used with reference to illness. 
The recent computer work on the writings of Thomas Aquinas gives us greater confidence and security in re lation to our subject. In discussing the meteorology of Aristotle, Aquinas makes a number of references to Hippocrates. He does so when discussing the meaning and role of stars in the cosmic order, theological questions, metaphysical principles, scientific theories, astronomy and astrology. 
3. Pastoral Medicine
Another category of sources where we find Hippocrates cited and quoted in church and theological documents is that of textbooks dedicated to pastoral medicine. Indeed there is a close relationship between the Corpus hippocraticum and theology not only because the Hippocratic writings constitute a tried and tested system of diagnosis and treatment but also because of their human image, their essential Christian basis, and their stress upon the notable similarities between sick and healthy people.
We should also take note of the ethical-medical chapters of the Didaché and the way in which they correspond to the writing and ideas of Hippocrates. The Greek physician is referred to on two occasions: when the behaviour of the marriage partners during pregnancy is discussed, and where there is a debate about the therapeutic opportunities offered by folk medicine in cases of epilepsy, something, of course, which today appears highly disputable. 
In 1893 E.W.M . di Olfers referred to Hippocrates in his book on pastoral medicine. He was much ahead of his time in his definition of epilepsy as a "holy disease" in the same way that every other illness is holy, and observed, in addition, that it was no more holy than any other. 
August Stohr makes repeated reference to Hippocrates, in part because he wants to attack a certain form of medicine proposed by the ancient Greeks, a form of medicine which has much in common with the therapeutic treatment of t he soul. In addition Stohr refers to Hippocrates when he discusses the classical idea of sex res non naturales and dwells upon diet and upon general customs and habits of an individual's life. , 
When considering the middle of the twentieth century we can cite Albert Niedermayer who makes frequent references to the Corpus Hippocraticum and to its ethical-medical high-point, the famous Hippocratic Oath. Like many other authors (Lichtenthaeler and others) he believes that this oath forms an authentic part of the Hippocratic writings.
In the work of Niedermayer there are arguments in favour of Hippocrates but also controversial statements, especially in the gynaecological field.
Albert Niedermayer has clear ideas about the importance of Hippocrates: "Even though he was a pagan he could today-some two thousand years after Christ's preaching of the Gospel-act as an example and model for doctors who proclaim themselves Christians."  Albert Niedermayer anticipated later overa ll and Wholistic approaches to medicine when he expressed his belief that a true and authentic doctor has a vision of his profession which "has at its base a fusion of biological, anthropological, medical-human, social, and ethical-metaphysical considerations, elements, and factors." 
Professor of Pastoral Medicine at the University of Vienna
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