The idea of the Church as a divinely ordained living organism, or 'Body of Christ'

The idea [or metaphor] of the Church as a divinely ordained living organism, or 'Body of Christ', was commonplace in early medieval ecclesiology.

https://en.wikipedia.org/wiki/Body_of_Christ

The importance of the organism in the political theory of John of Salisbury
https://doi.org/10.1017/S0143045900003355  https://goo.gl/ZXAh8Q

also in

Michael Wilks (1994). The World of John of Salisbury. Blackwell. ISBN 978-0-631-19409-5. pp 303-17

THE PHYSIOLOGICAL SIGNIFICANCE OF THE ORGANIC METAPHOR IN JOHN OF SALISBURY'S "POLICRATICUS"

Cary J. Nederman
History of Political Thought
Vol. 8, No. 2 (Summer 1987), pp. 211-223
Published by: Imprint Academic Ltd.
Stable URL: http://www.jstor.org/stable/26213292

John of Salisbury: Policraticus (Cambridge Texts in the History of Political Thought) - Internet Archive

John of Salisbury and Pseudo-Plutarch
Author: H. Liebeschütz
Source: Journal of the Warburg and Courtauld Institutes, Vol. 6 (1943), pp. 33-39
Published by: The Warburg Institute
Stable URL: http://www.jstor.org/stable/750420...
In Books V and VI [of the Policraticus John of Salisbury] leaves the Bible and arranges his material in terms of a new frame of reference: res publica is symbolized by the human body, and it is in terms of this image that John presents his analysis of the social organism. The head of the body politic is the king; the soul is the priest; the senate is the heart; the judges and administrators of the provinces are the eyes, ears and tongue; the knights are the hands and the peasants are the feet. It is the duty of the prince to keep the organism in good health, and in this the priesthood is pledged to help him; the relationship between church and state being expressed in terms of the relationship between soul and body. And it is this metaphor which determines the orders of the chapters in these two books.

There is no new feeling here for the character and organic unity of the state. John is expressing the common mediaeval conception of society as ecclesia, coming under two authorities, the spiritual and the secular, which have to work together in harmony.
...

The head of the body politic, the king or prince, is literally the "Head" of state.

Some Notes on John of Salisbury's Theory of Kingship as outlined in Policraticus Book IV

John of Salisbury outlines what he thinks the worldly and religious duties of a King ought be in his Policraticus Book IV. This book was dedicated by him to Becket whilst he was Henry II's Chancellor. John was in exile at the time when he wrote it, 1159.

John of Salisbury uses the terms "Prince" meaning  "Head of the Secular State" (King/Emperor/Prince), and "Republic" meaning the State (or Kingdom) itself.

Johannes (Sarisberiensis); Carey J. Nederman Ed and Tr (26 October 1990). John of Salisbury: Policraticus. Book IV: Cambridge University Press. pp. 27–. ISBN 978-0-521-36701-1.
https://goo.gl/ajrBwX

The Old Testament view of Kingship
Deuteronomy 17:14-20
https://goo.gl/eZVZan

The fourth book in Policraticus makes reference to the law of good kingship to be found in Deuteronomy.

14 When thou art come unto the land which the Lord thy God giveth thee, and shalt possess it, and shalt dwell therein, and shalt say, I will set a king over me, like as all the nations that are about me;

15 Thou shalt in any wise set him king over thee, whom the Lord thy God shall choose: one from among thy brethren shalt thou set king over thee: thou mayest not set a stranger over thee, which is not thy brother.

16 But he shall not multiply horses to himself, nor cause the people to return to Egypt, to the end that he should multiply horses: forasmuch as the Lord hath said unto you, Ye shall henceforth return no more that way.

17 Neither shall he multiply wives to himself, that his heart turn not away: neither shall he greatly multiply to himself silver and gold.

18 And it shall be, when he sitteth upon the throne of his kingdom, that he shall write him a copy of this law in a book out of that which is before the priests the Levites:

19 And it shall be with him, and he shall read therein all the days of his life: that he may learn to fear the Lord his God, to keep all the words of this law and these statutes, to do them:

20 That his heart be not lifted up above his brethren, and that he turn not aside from the commandment, to the right hand, or to the left: to the end that he may prolong his days in his kingdom, he, and his children, in the midst of Israel.

Some Notes

The Mediaeval conception of society is as ecclesia

It comes under two authorities, the spiritual and the secular, which have to work together in harmony.

The entirety of a king's authority is derived from God.

All law is a gift from God

The influential orator [Cicero], would seem to support this and to subject all men to its obedience because all law is a sort of discovery and gift from God, the teaching of the wise, the corrective to excesses of wilfulness, the harmony of the city, and the banishment of all crime.

Thus Chrysippus asserted that Law has power over all divine and human affairs, for which reason it presides over all good and all evil and is ruler and guide of things as well as of men.

All kings are obligated from necessity to observe the Law.

The king is not above the Law.

The Prince is a minister [servant] of priests and their inferior.

That the Prince is a minister [adjudtor, advocatus or assistant] of priests, and is their inferior; and what it is for rulers to perform their ministry faithfully.

The sword [of state] is accepted by the Prince from the Hand of the Church.

The Prince is therefore a sort of minister [servant] of the priests and one who exercises those features of the sacred duties that seem an indignity in the hands of priests. For all duties of sacred law are in fact the affairs of the religious and the pious, yet that duty is inferior which executes the punishment of crime and which seems to be represented by images of executioners.

That the authority of Divine Law consists in the Prince being subject to the Justice of Law.


The Prince is said to be an absolutely binding law unto himself, not because he is licensed to be iniquitous, but only because he should be someone who does not fear the penalties of law but someone who loves justice, cherishes equity, procures the utility of the republic, and in all matters prefers the advantage of others to his private will.

The prince is the public power and a certain image on Earth of the divine majesty. Beyond doubt the greatest part of the divine virtue is revealed to belong to the Prince,

Samuel deposed Saul by reason of disobedience, and substituted for him the humble son of Jesse atop the the kingdom.

http://biblehub.com/kjv/1_samuel/15.htm

Constantine [the Great] Emperor of the Romans ... when written accusations involving the crimes of priests ... to [him], he accepted them and placed them unopened in the fold of his toga. ... As he was a human subject to the verdict of priests, he himself then said it was not for him to examine divine cases which none except God could adjudicate. Those rolls which he had accepted he consigned to the flames uninspected.

1 Corinthians 2:15 King James Version (KJV)
The secular power is judged by the spiritual, the latter by no one
"But he that is spiritual judgeth all things, yet he himself is judged of no man."

References

Bernard of Clairvaux De Consideratione III, I, I https://goo.gl/eHymUc

John of Salisbury, ep. 44. Patr. Lat. 199, col. 274. 5 https://goo.gl/tbJBpF

Gosselin (M.) (1853). The power of the Pope during the Middle Ages, Volume II. J. Murphy. pp. 210–.

Medieval Sourcebook: John of Salisbury: Policraticus, Book Four (selections)

Kingship defined in the Old Testatment in the Bible

John of  Salisbury makes a reference in his book Policraticus on the Theory of Christian Kingship defined in the Old Testament in the Bible

Deuteronomy 17:14-20  https://goo.gl/3aeDFp and https://goo.gl/EqTo7c

In effect when the People of Israel arrive in the Promised Land they may set a leader above them, a King. The King will be "God Chosen" (appointed and crowned by the Church). from amongst their own people (he must not be a foreigner). When he is appointed [anointed and crowned] King he may not amass goods and wealth of huge value [gold and horses]  Nor should he acquire many wives. The Priests of the Levitical Tribe [The Church] should after his appointment [coronation] set down in writing all the laws of the kingdom, which he should read and study all his life whilst he is King.  He should "learn to fear the Lord his God, and keep His words and ceremonies, that are commanded in the law" and follow them religiously all his life, "that his heart be not lifted up with pride over his brethren [his own people]".

References

John of Salisbury Policraticus

Book IV Chapter 4

That the authority of divine law consists in the prince being subject to the justice of law.

Johannes (Sarisberiensis); Cary J Nederman ed and tr (1990). John of Salisbury: Policraticus. Cambridge University Press. pp. 35–. ISBN 978-0-521-36701-1.  https://goo.gl/xXbQ4Q

Internet History Sourcebooks Project Policraticus, Book Four (selections)

Pope Alexander III's Letter to Thomas Becket confirming Primacy of Canterbury

This was an attempt by the Pope to end the rivalry between the ecclesiastical provinces of York and Canterbury [and the See of London] in Canterbury's favour.

Roger (of Wendover); Matthew Paris (1849). Roger of Wendover's Flowers of History: Comprising the History of England from the Descent of the Saxons to A.D. 1235; Formerly Ascribed to Matthew Paris. 

Pope Alexander wrote to archbishop Thomas as follows:—

" In accordance with the example of our predecessors Pascal and Eugenius of blessed memory, we grant to you and your successors the primacy of the church of Canterbury, as fully as it was possessed by Lanfranc, Anselm, and their predecessors. Whatever dignities or privileges are known to belong to that church, we confirm to you by this present letter, as your predecessors have enjoyed them by the authority of the apostolic see, ever since the days of St. Augustine."

References

Primacy of Canterbury - Wikipedia

Canterbury–York dispute - Wikipedia

Saint Thomas (à Becket) (2000). The Correspondence of Thomas Becket, Archbishop of Canterbury, 1162-1170: Letters 1-175. Clarendon Press. pp. 272–. ISBN 978-0-19-820892-1.

Saint Thomas (à Becket) (2000). The Correspondence of Thomas Becket, Archbishop of Canterbury, 1162-1170: Letters 1-175. Clarendon Press. pp. 40–. ISBN 978-0-19-820892-1.

Saint Thomas (à Becket) (2000). The Correspondence of Thomas Becket, Archbishop of Canterbury, 1162-1170: Letters 1-175. Clarendon Press. pp. 63–. ISBN 978-0-19-820892-1.

Canterbury–York dispute - Wikipedia

STAUNTON, MICHAEL. "The Lives of Thomas Becket and the Church of Canterbury." In Cathedrals, Communities and Conflict in the Anglo-Norman World, edited by DALTON PAUL, INSLEY CHARLES, and WILKINSON LOUISE J., 169-86. Boydell and Brewer, 2011. http://www.jstor.org/stable/10.7722/j.ctt81q16.16.

Robert Somerville (1977). Pope Alexander III and the Council of Tours (1163): A Study of Ecclesiastical Politics and Institutions in the Twelfth Century. Council of Tours: University of California Press. pp. 35–. ISBN 978-0-520-03184-5.

Paul Dalton; Charles Insley; Louise J. Wilkinson (2011). Cathedrals, Communities and Conflict in the Anglo-Norman World. Boydell Press. pp. 169–. ISBN 978-1-84383-620-9.

The Confirmation of Becket’s Primacy: In apostolice sedis, Lateran, 8 April 1166’, Journal of the Society of Archivists, ix (1989), pp. 197–209.

Richard Hurrell Froude; James Bowling Mozley (1839). Remains of the Late Reverend Richard Hurrell Froude: v. 2.   The Question of Canterbury's Primacy and the Council of Westminster October 1163 J. G. & F. Rivington. pp. 62–.

Jean Truax (15 May 2017). Archbishops Ralph d'Escures, William of Corbeil and Theobald of Bec: Heirs of Anselm and Ancestors of Becket. Taylor & Francis. pp. 7–. ISBN 978-1-351-95752-6.

Gilbert Foliot and His Letters. CUP Archive. pp. 91–.

Gilbert Foliot and His Letters. CUP Archive. pp. 151–.

King Henry II's Letter to Reginald of Cologne [Rainald of Dassel]

Extract from

Roger (of Wendover); Matthew Paris (1849). Roger of Wendover's Flowers of History: Comprising the History of England from the Descent of the Saxons to A.D. 1235; Formerly Ascribed to Matthew Paris. 1168: King Henry II's letter to Reginald of Cologne: H. G. Bohn. pp. 556–.

King Henry II was exploring the option of  abandoning Pope Alexander III in favour of the schismatic anti-popes of the Holy Roman Empire.

King Henry, incensed against pope Alexander for having granted the primacy of England to the archbishop of Canterbury, sent the following letter to Reginald the schismatic archbishop of Cologne, an enemy to Alexander:— "I have long wished to have a just cause for withdrawing myself from pope Alexander and his perfidious cardinals, because they presume to maintain against me my rebellious subject, Thomas archbishop of Canterbury. Wherefore, with the consent of my barons and clergy, I am about to send as ambassadors to Rome the following eminent men of my kingdom—the archbishop of York, the bishop of London, the archdeacon of Poictiers, Richard de Lucy, and John of Oxford; to declare plainly and publicly to pope Alexander and his cardinals, on the part of myself and all my subjects throughout my dominions, that they must no longer maintain the cause of that traitor, but release me from him, so that I may, with the consent of my clergy, appoint another archbishop to the see of Canterbury, and that they must annul immediately all the acts of the said Thomas. They will also demand that the pope shall swear publicly, for himself and his successors, to observe all the royal customs of my grandfather king Henry, entire and inviolate, for ever. But, if they shall refuse their consent to any of my requests, neither I, nor my barons, or clergy, will obey them any longer; but will openly take part against the pope himself and his cardinals, and expel from the kingdom any one, who from that time shall espouse his cause. We therefore request of you, as our dear friend, to send to us immediately, without delay, brother Arnold the Hospitaller, on the part of the emperor and yourself, to escort my ambassadors through the emperor's dominions.—Farewell!"

It was reported by the clerks and notaries of the king, that Gilbert bishop of London dictated this letter at the king's request, to ruin the cause of the pope, the archbishop of Canterbury, and the whole English church: wherefore, also, it happened one night that whilst Gilbert was lying awake in bed, and meditating without compunction how he might bring confusion on the archbishop, by means of this iniquitous letter, he heard a terrible voice saying over him in loud and plain terms:

« 0 Gilbertus Foliot,
Dum revolvis tot et tot,
Deus tuus est Astaroth! "

References

Wilfred Lewis Warren (1973). Henry II. University of California Press. pp. 492–. ISBN 978-0-520-02282-9.

Frank Barlow (1990). Thomas Becket. University of California Press. pp. 136–. ISBN 978-0-520-07175-9.
Constitutions of Clarendon: Henry II's Dealings with the Holy Roman Empire, 1165-6

Richard Hurrell Froude; James Bowling Mozley (1839). Remains of the Late Reverend Richard Hurrell Froude. J. G. and F. Rivington. pp. 127–.
http://elfinspell.com/KingsLettersHenryIId.html

https://en.wikipedia.org/wiki/Rainald_of_Dassel

https://sourcebooks.fordham.edu/source/hoveden-becket.asp

J. A. Giles (1846). The Life and Letters of Thomas À Becket: Now First Gathered from the Contemporary Historians. King Henry's letter to Reginald archbishop of Cologne.: Whittaker. pp. 316–.

Paul Webster; Marie-Pierre Gelin (2016). The Cult of St Thomas Becket in the Plantagenet World, C.1170-c.1220. Chapter 6: Matilda, Duchess of Saxony (1168-1196) and the Cult of Becket: Boydell & Brewer. pp. 113–. ISBN 978-1-78327-161-0.
http://vidimus.org/issues/issue-112/books/

Michael Staunton (2001). The Lives of Thomas Becket. Manchester University Press. pp. 139–. ISBN 978-0-7190-5455-6.

Joseph Patrick Huffman (2009). The Social Politics of Medieval Diplomacy: Anglo-German Relations (1066-1307). University of Michigan Press. pp. 57–. ISBN 0-472-02418-3.

England and the Empire in the Early Twelfth Century
K. Leyser
Transactions of the Royal Historical Society
Vol. 10 (1960), pp. 61-83
Published by: Cambridge University Press on behalf of the Royal Historical Society
DOI: 10.2307/3678774
Stable URL: http://www.jstor.org/stable/3678774

Joseph Patrick Huffman (16 November 2009). The Social Politics of Medieval Diplomacy: Anglo-German Relations (1066-1307). 2 Renovatio Regnorum et Archepiscoporum: University of Michigan Press. pp. 57–. ISBN 0-472-02418-3.