Classical Canon Law

by Philip Jones

No originality is claimed for this paper.  It is based on a review of English-language commentaries, and is intended to provide clarification for those unfamiliar with the subject, including the author.  The commentaries referred to are listed at the end.

The years 1140 to 1375 are known as the ‘classical period’ of canon law, because it was during this time that canon law ‘attained its definitive shape and most enduring characteristics’ (Brundage, p.48).  Gratian’s Decretum inaugurated classical canon law.

The Decretum

Gratian was by no means the first canonist at Bologna.  The study of canon law at that university (the oldest in Europe) had started in the wake of the ‘investiture controversy’ between the papacy and the emperor, which had erupted in the century before the classical period started (Ullmann, p.164).  There were early attempts to create a canonical jurisprudence by Pope Urban II (Pope 1088-99) and Ivo of Chartres (d.1115) (1947 report, p.20).

Ivo of Chartres identified two kinds of law:

(1) law laid down by God in the Bible or in ‘natural law’ and

(2) law made by the Church in the course of history.

The purpose of both laws was the salvation of souls.  Ivo’s work, the Panormia, was the principal text book of canon law before Gratian’s Decretum (1947, p.23).

Another early canonist, Bernold of Constance (d.1100), made the discovery that ‘many of the divergences in [canonical] texts … were due to their historical context: they did not represent contradictions in the law so much as the application of the law in a changing historical scene’ (1947 report, p.21).  Bernold also discovered a ‘hierarchy of texts … a canon of a general [ecumenical] council was to be followed in preference to a canon of a local synod, and [papal legislation] in preference to the canon of a general council’.  These discoveries anticipated Gratian’s work.

Little is known of Gratian personally.  He may have been a monk, as the Decretum apparently shows a ‘strong emphasis on and detail concerning monastic affairs’ (Christensen, p.x).  The Decretum was probably written c.1140, and there is evidence that Gratian was already deceased by the 1160s.

The Decretum has 3800 texts, arranged in three sections:

(1) the nature of law and authority, including Church discipline and orders

(2) a discussion of 36 fictional cases (similar to ‘moots’)

(3) sacraments and worship (p.ix).

Gratian”s source material was enormous, ‘from the Decalogue to the enactments of contemporary Councils’, and included scriptural and patristic texts, papal documents and ‘rulings of a millennium’s worth of councils and synods’ (p.xii).  However, Gratian probably consulted only a relatively small number of existing collections for his material.  Early canonists made particular use of the writings of the great Latin fathers, Cyprian, Ambrose, Augustine and Gregory the Great (1947 report, p.22).

Helmholz gives an account of one of Gratian’s fictional cases (pp.39-40).  Is it lawful for a bishop to appoint his own successor by will?  There was some authority to support such an appointment.  The Pope had on one occasion permitted an Archbishop of Mainz to name his successor.  St. Peter, the first Bishop of Rome, had, according to tradition, nominated Clement to succeed him.

On the other hand, an early Council had ruled that a bishop was not at liberty to choose his successor.  The Bible records that Moses was given a special power to choose his successor, but he had picked someone from outside his own tribe.

From these authorities Gratian deduced the admirable principle that the appointment of a bishop should not be governed by familial connections but by merit.  He therefore concluded that it would be unlawful for a bishop to appoint his own successor by will.

Gratian’s method was to harmonize the law by identifying distinctions between apparently contradictory rules, distinctions which now seem obvious, but which were hardly understood in his day:

(1) one rule was later in time, and so superseded an earlier rule

(2) different rules might apply in different places

(3) a rule made by a superior authority overrode one made by an inferior authority

(4) one rule was of general application, while another was intended to apply only by way of an exception to the general rule (Reichel, p.105).

The full title of the Decretum is Concordantia Discordantium Canonum, or ‘The Harmony of Discordant Canons’.

The Decretum was thus a ‘comprehensive effort to standardize the canon law’ (Christensen, p.xvi).  It has been called ‘the most successful textbook ever written’ (Ullmann, p.165).  However, there is no extant ‘base manuscript’ of the work.  The edition now most commonly referred to was produced by a papal commission in 1582, some 440 years after the original work.  Other editions were produced in Germany in the 18th and 19th centuries (Christensen, p.xix).

The classical canonists helped create scholastic methodology (Brundage, p.154).  Gratian lived and wrote 100 years before St. Thomas Aquinas, who made extensive use of the Decretum in his own writings.

Decretals, Collections and the Corpus

Pope Alexander III (Pope 1159-81) had been Gratian’s pupil, and turned his theories into law (Ullmann, p.167).  Alexander III and Innocent III (Pope 1198-1216) were the outstanding ‘lawyer-popes’, though other popes of this era had a legal background too (1947 report, p.26).  The papacy became ‘the great prize of the legal profession’.

The papal law of this era mostly took the form of rescripts, usually described as decretals (Brundage, p.160).

Kemp cites a decretal which took the form of a letter from the Pope to a French archbishop, in which he criticizes the constitution of the archbishop’s cathedral (pp.19-20).  The cathedral constitution apparently ‘introduces an inequality between the old and the new canons’ i.e the cathedral clergy.  The Pope’s letter ‘lays down the principle that he who makes a law for another should be prepared to obey it himself’.  This example illustrates how classical canon law may have worked in practice.  It did not impose any radically new regime, but rather rationalized and corrected existing laws and customs.

Kemp concludes that, while some decretals have a legislative character, most (including the example discussed above) resemble judicial decisions, ‘leading cases’, which establish principles and precedents, rather than legislation in the modern sense (p.21).  All political authority at this time was understood in judicial terms.  The Pope was the supreme judge, rather than the supreme legislator (Helmholz, p.38).

As ever more decretals issued from the papal chancery, collections of decretals began to be made by individuals for their private and professional use (Reichel, p.111).

Worried that forged decretals were circulating, the popes commissioned official collections.  Pope Gregory IX (Pope 1227-41) commissioned St. Raymond of Penyafort (c.1185-1275), a Dominican friar, to compile a collection of his decretals (Reichel, p.113).  The total compilation came to five books, though they were collectively known as the Liber Extra (presumably because they were extra to the Decretum, which was considered the standard work of canon law).

In 1234 the Liber Extra was finally dispatched to the universities of Bologna and Paris, with Pope Gregory’s instruction ‘that all persons should make use of this compilation only, as well in judicial proceedings as in the schools [i.e universities]’.

In 1298, Pope Boniface VIII (Pope 1294-1303) dispatched a further collection of decretals, the sixth book or Liber Sext issued since Gregory IX’s collection (p.116).  Pope Clement V (1305-14) ordered the last official collection of decretals, known as the Clementines, in 1317 (Brundage, p.198).

Brundage writes that ‘By 1325 decretal letters had ceased to be the principal vehicles for legal innovation in the Western Church … the decisions of the papal courts, especially the Roman Rota, assumed an increasingly prominent role’ (p.56).

The Corpus Iuris Canonici was not compiled until the early 16th century, long after the classical period of canon law had come to an end (1947 report, p.26).  Thus the classical canonists would not have understood canon law in terms of a single Corpus.  That came much later.

Like the Decretum, the compilation of the Corpus was the work of a private individual, a Parisian publisher called Jean Chappuis.  The Corpus comprised six parts:

(1) Gratian’s Decretum (c.1140)

(2) The Decretals or Liber Extra of Gregory IX (1234)

(3) The Liber Sext of Boniface VIII (1298)

(4) The Clementines of Clement V (1317)

(5) The 20 bulls or Extravagantes of John XXII (Pope 1316-34) (1500)

(6) The Extravagantes Communes, miscellaneous papal decretals issued by popes from Boniface VIII to Sixtus IV (Pope 1471-84) (1500).

The Extravagantes were a small private collection of decretals compiled in 1325-7 by Zenzelinus de Cassanis (d.1354).  The Communes were compiled by Chappuis himself (Brundage, p.199).

Thus the Corpus was a combination of private enterprise and public authority.  Three parts of it, (1), (5) and (6) were private collections.  The other three parts (2) to (4), were official papal collections.

Tierney points out that ‘The Decretum was radically different in structure from the later parts of the Corpus Iuris Canonici.  They [the papal collections] were codes of authoritative law.  The Decretum was a running argument … [with] the judicious citation of texts on both sides of all questions discussed’ (pp.24-5).  In other words, the collections of decretals comprised legislation and judicial decision, whereas the Decretum was an academic commentary.

At the end of the 16th century a lawyer from Lyons, Peter Matthew, made a collection of decretals which was intended to form the ‘seventh book’ of the Corpus (Reichel, p.121).  However, the book was not a success and was placed on the Index in 1623, on account of its ‘many inaccuracies’ (p.121).  A papal commission also worked on an intended seventh book of the Corpus, but this too was suppressed (pp.121-2).

Academic Commentary

Referring to the mediaeval decretals Brundage observes that ‘This spurt of new [papal] lawmaking was stimulated, at least in part, by the success of Gratian’s work, for the teachers who expounded his Decretum discovered in the process numerous problems for which existing canon law either furnished unsatisfactory solutions or none at all’ (p.53).

However, the profusion of new papal legislation rendered the Decretum out of date as the old laws that had been the subject of the Gratian’s ‘distinctions’ were superseded (1947 report, p.26).  The Decretum was mostly based on theological material, but in the era of the decretals, canon law finally emerged as a separate academic discipline from theology (p.30).

Around the authorised papal collections that came to form the Corpus, there grew up ‘a mass of commentaries and explanations at the hands of a body of expounders and teachers’, in other words, academic lawyers (Reichel, p.125).  Academic commentary usually took the form of a gloss, a comment endorsed on the margin of a legislative instrument.

There were two categories of academic commentator, decretists and decretalists.  Some commentators were both decretists and decretalists (Tierney, p.87).  However, while the decretists wrote commentaries on Gratian’s work, the Decretum, the decretalists arranged, and commented upon, the papal laws (i.e decretals) that appeared after the Decretum was written (Reichel, p.28).

Ullmann suggests that there was an ‘intimate connection’ between the schools of canon law (especially Bologna) which studied the laws, and the papacy which decided and made the laws (p.163).  There was a circular relationship between the papacy and academe.  The commentators’ interpretation of canon law precipitated new papal legislation to resolve anomalies and fill lacunae.  This new legislation became in its turn the subject of further academic comment, thus prompting further legislation, and so on.

Reichel writes that the canonists’ method of interpreting papal legislation by the scholastic method, and the acceptance of this method in courts throughout western Christendom, ‘made the canonists’ exposition of the law supreme and the school of canonists the lawmakers of the Church’ (pp.134-5).

Henry of Segusio (d.1271, the Cardinal-Bishop of Ostia and therefore known as Hostiensis) was the author of a commentary known as the Summa or Summa Aurea (‘the golden summa’) (Brundage, p.214).  This was an introduction to the decretals of Pope Innocent IV (Pope 1243-54), ‘in which the severer views of that pope were somewhat toned down’ (Reichel, pp.130-1).

Johannes Andreae (c1270-1348), a professor at Bologna (and victim of the Black Death) was another decretalist.  He wrote a treatise called the Novella.  He was assisted in his academic work by his daughter.  She read his lectures to the students, though ‘for fear of distracting attention by her great beauty lectured from behind a curtain’ (Reichel, p.132).  This indicates that the teaching of canon law was a profession open to married laymen as well as priests and religious.

Eminent canonists received gushing soubriquets, presumably bestowed by admiring pupils (Reichel, pp.130, 132, 134).  Hostiensis was ‘the light of the law’ and ‘sovereign of both laws’ (iuris utriusque monarcha).  Johannes Andreae was ‘the fountain and trumpet of the law’ (iuris canonici fons et tuba).  Another canonist, Bartolus of Sassoferrato (b.1313) was acclaimed ‘the light and star of a lawyer’ (iuris consulti), master of truth, lamp of right and guide of the blind’.  Nicholas of Tudeschi (1386-1453, Bishop of Palermo and known as Panormitanus) was also ‘the light of the law’ (lucerna iuris).

The difference between canon law and English common law was that the latter developed by case law, decided by judges in courts, whereas canon law was based on legislative texts with superadded academic commentary.  The ius commune was dominated by law professors rather than judges (Helmholz, pp.30, 23).

However, the contrast should not be pressed too far.  As Kemp points out, much papal ‘legislation’ actually resembled case law, while English common law was taught after a fashion, but in the inns of court rather than at university.  It may be that the essential difference between English common law and canon law was that the former was a much smaller scale activity than the latter.  The distinction between studying and deciding English law was therefore less clearcut.  The courts of Westminster Hall would have been a small jurisdiction then by comparison with the ecclesiastical courts of all Europe.

Canon Law and Roman Law

The development of canonical jurisprudence was undoubtedly influenced by the study of Roman or ‘civil’ law.  The study of Roman law had revived at Bologna in the century before Gratian wrote.  However, Gratian and other early canonists worked primarily from theological material, not Roman law texts.  The study of Roman law was initially a somewhat controversial activity.  The devout were suspicious of Roman law on account of its pagan origins (Winroth, p.184). 

Helmholz explains that canon law was ‘separate and distinct from both theology and Roman law, though it overlapped with both in its coverage and sources’ (p.5).  Canonists ‘made constant use of Roman law, but they did not feel themselves bound by its rules’.  There was apparently a common saying in mediaeval times that ‘Ecclesia vivit lege Romana‘ (p.89).

Gratian adopted from Roman law the tripartite division of laws into those concerning things, persons and actions (Reichel, pp.106-7).  The Decretum also contains about 200 texts (out of 3800) drawn from Roman law (Christensen, p.xiv).

Rodes describes canon law as ‘Christian theology structured by Roman law’ (p.46).  He writes that ‘the theological principle of the primacy of the Pope was given its juridical form … through analogy of the place of the Emperor in the Roman law’ (p.47n).  Helmholz confirms this (p.20).

Kuttner suggests that it was only through the medium of canon law that Roman law came to be the law of much of Europe, instead of being merely a subject of academic study (Role, pp.353-4).  The most visible use of Roman law by canon law was to regulate the procedure of the ecclesiastical courts (Kemp, p.19).

However, biblical theology and Roman law did not always blend smoothly.  For example, the Roman and Jewish ideas of marriage were not easy to reconcile.  The result of this difficulty was that ‘mediaeval canon law vacillated … between consent [Roman law] and marital intercourse [Jewish-biblical] as the effective consummation of the marriage’ (Rodes, p.47n).  It is arguable that this uncertainty about the true nature of marriage is still apparent in the modern Western attitude towards homosexual ‘marriage’, which can be justified on the basis of mutual consent, but which cannot have any basis in marital intercourse, which is particular to heterosexual relations.

The great difference between canon law and Roman law was that the latter was, if not a ‘dead’ law, then ‘a closed body of texts’ (p.6).  The whole of Roman law had been written in the later Roman Empire.  Canon law, by contrast, was still being made by Popes and councils.  Canon law therefore had a dynamic character, while Roman law was static.

There were separate canon law and Roman law faculties in mediaeval universities, a clear indication that canon law was regarded as a separate discipline (Helmholz, p.6).  Nevertheless, the canon law on most subjects was influenced by Roman law (p.18).  Notwithstanding the separate faculties, the two laws converged into a ius commune (p.20).

References to the ius commune appear from the late 13th century onwards (Brundage, p.60).  This mediaeval convergence explains why most modern law degrees are still known formally as laws degrees (plural) denoted by abbreviations such as LL.B and LL.D.

Thus the notion of a ius commune comprising both canon law and Roman law, predated the compilation of the Corpus Iuris Canonici by a long time.  This Corpus was itself a conscious imitation of the Emperor Justinian’s Corpus Iuris Civilis of Roman law.


Kuttner describes the achievement of the mediaeval canonists as ‘a consistent, rationalized ecclesiastical jurisprudence’, developed by a ‘slow process of organizing thought interlocking with customs and practices that differed [widely] from each other’ (Methodological Problems, p.541).  The canonists created a science of canon law by ‘dealing in first principles, and giving logic and cohesion to the actual law in force’ (1947 report, p.20).

Canonists saw their subject as ‘a universally applicable norm of right living in a Christian society’ (Ullmann, p.179).  Thus mediaeval canon law was much more than a merely ‘Church’ law regulating ecclesiastical institutions and persons.

On the contrary, Helmholz writes that canon law ‘was not confined to ecclesiastical subjects straitly defined … It reached subjects as diverse as theft, wills and succession to property, and the sale of goods’ (p.1).  The purpose of canon law was ‘to regulate the whole life of the Church’ (p.4).  This meant that laypeople and secular rulers were subjects of canon law, not merely clergy and Church courts.  Mediaeval canon law was a ‘pan-European system of law’ (p.5).

The authors of the 1947 report, who were seeking to persuade an apathetic Church of England to adopt a programme of law reform, were full of admiration for the mediaeval lawyer-popes: ‘Churchmen gladly accepted their law from these mitred lawyers … because their court was the best place in Europe at that time to go for good law’ (p.5).

Kuttner argues that the canonists’ doctrine of ‘just war’ forms the basis of modern international law.  The canon law of corporations or ‘corporate representation’ laid the foundations of constitutional law.  The doctrine of equity in English law originated in mediaeval canon law.  The doctrines of mens rea and ‘medicinal’ punishment have greatly influenced modern criminal law (Role, p.352).  According to Brundage, the canonists’ approach to criminal law ‘lies at the root of most modern theories of criminal justice’ (p.171).

Gratian’s Decretum provided a theory of sovereignty, with the Pope as ‘direct sovereign lawgiver of the Church’ (1947 report, p.25).  The decretalists, commentators on papal laws, were more avowedly papalist than the decretists (Tierney, p.88).  Classical canon law was also the ius pontificium.

However, the papalism of the classical canonists may have been exaggerated by historians, because in the controversies that followed the Great Schism of 1378, conciliarists as well as papalists ‘drew their weapons from the canonists’ armoury’ (Tierney, p.13).  The deposition of a reigning pope was by no means a taboo subject in mediaeval academe.  Gratian himself had apparently asserted that the Pope could be deposed for heresy or schism (p.8).

The canonists had a robust attitude to outdated law, holding, in contrast to Roman lawyers, that laws ceased to have effect when the reason that had prompted their promulgation had ceased to exist (Lacey, p.173).

A possible shortcoming of canon law was that neither canonists nor Roman lawyers observed any doctrine of judicial precedent similar to that of modern English law (Brundage, p.159).  This could give rise to uncertainty and inconsistency.

Mediaeval canon law may have had a didactic, hortative character not found in modern law and therefore not easy to understand now.  It was a form of preaching rather than regulation, ‘the basis for the imposition of a moral ideal through the exercise of pastoral solicitude’ (Rodes, p.65).  The purpose of canonical sanctions was the sinner’s repentance and salvation, not his punishment, nor the compensation of his victims (if any) nor the deterrence of others from similar offences (p.93).

Classical canon law is most often criticised for its supposedly excessive legalism.  One 19th century writer asserted that ‘The worst corruption of the middle age lay in the transformation of the sacerdotal hierarchy into a hierarchy of lawyers’ (quoted by Reichel, p.126).

Kuttner observes that classical canon law has been depicted as a corrupting, even pagan, influence on the Church.  The use of concepts and techniques borrowed from Roman law was alleged to have debased the ‘sacramental’ character of earlier canon law into a ‘juristic and corporational epoch’ (Reflections, p.202).

Kuttner rejects this view, pointing out that even the early Church dealt with its proprietary and material affairs just as much as the late mediaeval Church (p.205).  He observes that ‘The interlacing of the ‘spiritual’ and the ‘material’, corporate side of the Church is as old as the Church herself … It is grounded in the dual nature of the Church as a spiritual communion and as a corporate society at the same time … The dual aspect ultimately flows from the mystery of the Incarnation and returns … on all levels of ecclesiastical life’ (Role, p.356).

However, Kuttner concedes that the effects of classical canon law were not all beneficent.  Canon law did, indeed, become infected by a petty bureaucratic legalism, with the result that ‘the law would become an end in itself’ (Reflections, p.208).  The practice of granting dispensations was abused as a device for flouting and evading just laws.  The papacy acquired unedifying ‘imperial’ pretensions.

The canon law’s treatment of marriage has also been criticised.  Lacey and Mortimer roundly assert that ‘mediaeval canon law failed miserably as guardian of the holy estate’ (p.138).  The complexity of the law concerning the various impediments to marriage, and dispensations from those impediments, made an immense number of marriages precarious, and led to a ‘general weakening of the sense of sanctity and indissolubility of the marriage bond’ (pp.138-9).

The End of Classical Canon Law

The 1947 report notes that ‘The reign of [Pope] Clement V [Pope 1305-14] brings to an end the age of papal codes’ (p.36).  Thereafter the legislative activism of the papacy abated.  Later papal legislation ‘consisted chiefly of rules governing the procedure of [papal] bureaucracy’.  The academic canonists for their part ‘were content to admire the finished structure and to comment on it and explain it’.

Nicholas of Tudeschi was ‘the last of the great canonists in whose method sound matter had not as yet been displaced by inept formality’ (Reichel, pp.133-4).

The classical period of canon law ended just as the Great Schism of rival papacies began in 1378.

Protestants never liked classical canon law because of its associations with the papacy and because of the supposed corruptions discussed by Kuttner.  Martin Luther pitched a copy of the Liber Extra into the fire to symbolize his rejection of papal authority (Lacey, p.182).  After his break with Rome, King Henry VIII forbade the teaching of canon law at Oxford and Cambridge.

During the Counter-Reformation Pope Pius IV (Pope 1559-65) even forbade comments and glosses on the decrees of the Council of Trent (Reichel, p.121), which can hardly have encouraged the study of canon law.  Kuttner writes graphically of post-mediaeval canon law that ‘it had become like a tropical forest in which living and dead growths are hopelessly intertwined’ (Methodological Problems, p.540).  It lost its intellectual dynamism as ‘The free interplay of judicial and academic spheres became replaced by the [Roman] bureaucratic process’ (Reflections, p.208).

List of Works Cited

Brundage, J.A, Mediaeval Canon Law (Longman, 1995)

The Canon Law of the Church of England (Report of Archbishops’ Commission, SPCK, London, 1947, ‘the 1947 report’)

Christensen, Katherine, Introduction to Gratian, The Treatise on Laws translated by A. Thompson and J. Gordley (CUA Press, 1993)

Helmholz, R. H, The Spirit of the Classical Canon Law (University of Georgia Press, 1996)

Kemp, E.W, An Introduction to the Canon Law of the Church of England (Hodder and Stoughton, London, 1957)

Kuttner, Stephan, ‘Methodological Problems concerning the history of Canon Law’, Speculum (1953)

– ‘Reflections on Gospel and Law in the history of the Church’ (1976)*

-‘ The Role of Secular Law and Institutions in the History of Canon Law’ (1953)*

* published in Studies in the History of Mediaeval Canon Law (Ashgate, 1990)

Lacey, T.A and Mortimer, R.C, Marriage in Church and State (1912-47)

Reichel, Oswald J, The Canon Law of Church Institutions, volume 1 (SPCK, London, 1922)

Rodes, Robert E,  ‘The Canon Law as a Legal Obligation’, Natural Law Forum (1964, p.45)

Tierney, B, Foundations of the Conciliar Theory (CUP 1955)

Ullmann, W, Law and Politics in the Middle Ages (CUP 1976)

Winroth, Anders, ‘Roman Law in Gratian and the Panormia’, in Brassington, B.C and Cushing, K.G (eds), Bishops, Texts and the Use of Canon Law around 1100 (Ashgate, 2008).