At Cambridge, it is obligatory to study Roman law. We look at ancient laws codified in works, such as the Institutes of Gaius (161 AD) and Justinian’s Corpus Iuris Civilis (534 AD). The Corpus Iuris Civilis codified, interpolated and amended Roman law to suit the vision of the ambitious Emperor Justinian. It is the foundation for the Romano-Germanic family of legal systems, also known as “civil” or “civilian” systems.1 English law is not part of this legal family and instead it belongs to the common law legal family.
Some students continue their study of Roman law by taking “Civil II” or “Private comparative law” in their second or third year. Those who don’t have minimal contact with Roman systems and must simply accept that the families are “just so different” as decisive features are often poorly defined and their relative importance left unexplained.2
But how different are these families? How and why have major differences developed? To attempt to compare certain key private law difference between these two large legal families, it is necessary to have a clear idea of what you are comparing.
A legal family is a “genealogically” structured group of legal systems. There is the parent legal system and its historical offspring or siblings. 3 English law is the parental system of the common law family and its offspring can be found in the Commonwealth (such as Australia) and former colonies (such as the USA). Roman law is the parent of the civil family and its offspring are the legal systems seen throughout Europe and the former colonies of European empires.
A legal system is based on technical criteria such as the general nature and content of the law and the structures and methods whereby it is legislated upon, adjudicated upon and administered, within a given jurisdiction.4
It is important to understand the historical development of both of these families in order to explain their individual key features and their relationship with each other. Kischel stresses that history is only relevant insofar as it continues to shape the contemporary context.5 Legal history is not comparative law.
The study of the common law family must begin with a study of English law6. The common law began in England during the 11th century after William the Conqueror established a feudal system following the Battle of Hastings in 1066. During the reign of Henry II (1154-1189) “the whole of English law [was] centralised and unified”7. The Chancery Court issued writs in the King’s name that were to be applied in all areas of the kingdom. It was a legal system common to the whole kingdom, which gave it the name the “common law”.
Judge made law is at the core of the common law systems. Judicial precedent has authority as a source of law. As such, common law systems are considered to be an “open system” as new rules can be created for new factual situations. It is considered to be more detailed than civil law.8
The civil family, as explained above, is based on the Corpus Iuris Civilis. It is important to note that the Digest was codified in the Byzantine period and so Roman law had to be re-introduced to Western Europe. The process whereby Roman law was taken up by court practice and applied as a substitute to existing legal systems is known as the “reception” of Roman law. 9 The first stage of the reception of Roman law in Europe, the re-discovery of the Digest, occurred around the same time as the foundation of the common law in England (in the late 11th or early 12th century). Stein explains that the Church was eager to “exploit the newly discovered texts to justify [their] new ideas”10. Roman law became entwined with ecclesiastical law and slowly spread across the continent. The reception of Roman law was enhanced in the 16th century when Roman law moved in the secular courts.11 By this time the common law had been operative for centuries, and this inhibited Roman law’s reception in England. However, it should not be ignored that there was cross-influence between the two families. R. Pound has famously described the history of a legal system “a history of borrowings”12
There are two types of modern Roman law system: codified (as seen in Continent Europe and Québec) and uncodified Roman law (as seen in Scotland and South Africa). Civil law systems rely more on broad, general principles than common law systems and tend to adhere to Montesquieu’s theory of the complete separation of powers. Judge made law therefore has an “authority of reason” but not the law-making authority seen in common law systems. They are considered “closed systems” in which every possible situation is governed by a limited number of general principles. 13
Their historical development can explain overarching differences between the two legal families. However categorising systems into legal families is only an “accessible and mangeable”14 springboard to begin a comparative analysis as it provides necessary introductory context. 15 Comparing “common law systems” and “civilian systems” in grand terms would be simplistic16 and abstract. It is necessary to choose certain legal areas in these systems to compare in depth.
Studying droit privé comparé at l’Université de Poitiers has introduced me to certain differences between the civil and common law families that I would like to explore. First, it seems that, unlike common law systems, civil systems do not have a concept of relativity of title and instead have a unitary concept of ownership. Second, civilian systems lack the historic separation between law and equity17 Third, the concept of good faith is present in civilian systems, whereas it is traditionally absent from the English common law.
When the goal is to compare these areas in the legal families, choosing which legal systems to compare presents an extra difficulty. Each branch of the family tree on both sides has grown in its own way. You could spend as much time conducting a comparative exercise amongst family members as between the families. Should we compare American law with German law? Or English and Italian? Or Australian and French? None of these individual systems are representative of the family as a whole. No matter which you choose the goal of the exercise is already be lost. It would no longer be a comparison between “common law” and “civilian” families but comparing the two chosen systems.
A solution may be to forego a direct comparison between one “common law” jurisdiction and one “civil jurisdiction” and look at how “mixed jurisdictions” understand the areas targeted for comparison.
The term “mixed jurisdiction” was coined by T.B. Smith in 1962 to describe “basically a civilian system [that] has been under pressure from the Anglo-American common law and has in part been overlaid by that rival system of jurisprudence.”18 However, there is no agreed definition. F.P. Walton defined it as a “legal systems in which the Romano-Germanic tradition has become suffused to some degree by Anglo-American law”19. Both of these definitions take Roman law as the foundation but to avoid potential presumptions Robin Evans-Jones’ definition should be preferred. He defines a mixed system as “a legal system which, to an extensive degree, exhibits characteristics of both the civilian and the English common law traditions.”20
Looking at these “laboratories of interaction”21 would allow for more in-depth analysis of legal issues and help us identify which elements belong to which legal family. The mixed jurisdictions that I have chosen to look at are: Scotland, Quebec and South Africa.
The Scottish legal system took on a fundamentally civilian character during the Dark Ages at the height of the Auld Alliance (an alliance between Scotland and France promising mutual defence against English). This was consolidated by the reception of Roman-Dutch law rules and principles during the 16th century. It retained this civilian character despite the Union of the Crowns of Scotland and England in 1603. However, this changed after the Treaty of Union (1707) abolished the Scottish Parliament and made the House of Lords the final court of appeal in Scottish civil matters. English law then became the strongest external influence on the Scottish legal system. Scots law took on more of a common law character22 and continues to do so today. Some consider Scots law to be “truly a mixed system” long before 1707.23 It has drawn upon diverse sources including feudal law and canon law alongside the two main legal families.
The Republic of South Africa’s legal system contains elements of Roman law, common law, and tribal customary law. The first Dutch settlers established Roman-Dutch law in the region of the Cape of Good Hope in 1652. When control of the Cape was transferred to the British in 1815, Roman-Dutch law continued to develop and was imported to the Boer Republics established outside the British rule of the Cape. Statutory English law was introduced into the Cape Colony during the 19th century and the common law began to influence South African legal systems. The new Republic of South Africa (established in 1961) continues to give “approximately equal weight” to both Romano-Dutch law and the English common law. There is an additional recognition of African customary law which must be applied where possible.24
Quebec was founded as a French colony in the early 1600s but was ceded to the British under the Treaty of Paris (1763) after the Seven Years’ War. Unlike in South Africa, the British attempted to eradicate the practice of French civil law but this was met with strong resistance by the French population. In response, the Quebec Act 1774 preserved the “laws of Canada” (the civil law) whilst imposing the English criminal law. The Constitutional Act 1791 divided the Province of Quebec into “Upper” (where the English common law was then established) and “Lower” Canada (where civil law was unaffected). The Act of Union 1840 brought the two regions back together to form the Province of Canada. In 1867 Canada became a Crown Dominion, an autonomous country within the British Commonwealth,25 following the Constitutional Act 1867 (also known as the British North America Act 1867). The Code of Civil Procedure of the same year blended the common law and civil elements into a “synthetic whole” which has been upheld by the current Civil Code of Quebec (1994). 26
To conclude, mixed jurisdictions are the best prism through which to make a comparative analysis between the civil and common law legal families. This allows for more than a mere comparison between individual common and civil systems, allowing for more holistic discussion. Looking at mixed jurisdictions makes it possible to identify how target areas have developed in those systems and whether they are more in line with civil or common law legal traditions. In further instalments, I will look at: the concept of ownership, equity, and the concept of good faith.
1. Kischel, Comparative Law, Chapter 4 : Legal Families, Legal Culture, and Context, Oxford Scholarship Online: April 2019  https://www-oxfordscholarship-com.ezp.lib.cam.ac.uk/view/10.1093/oso/9780198791355.001.0001/oso-9780198791355
2. Ibid. 
3. Ibid. 
4. William Tetley QC, Mixed jurisdictions : common law vs civil law (codified and uncodified) (Part I), Rev. dr. unif. 1999-3, p595
5. Kischel, 
6. René David / Camille Jauffret-Spinosi / Marie Goré, Les grands systèmes de droit contemporains, DALLOZ, Septembre 2016, p241, 
7. Federic Maitland, 7he History of English Law, 2 vols., 2d edn. (Cambridge, 1968), 1: 136
8. William Tetley QC, Mixed jurisdictions : common law vs civil law (codified and uncodified) (Part I), Rev. dr. unif. 1999-3, p597
10. Stein, Roman law in European history, Cambridge University Press,1999, p44
12. William Tetley QC, Mixed jurisdictions : common law vs civil law (codified and uncodified) (Part I), Rev. dr. unif. 1999-3, p598, see A. WATSON, Legal Transplants: An Approach to Comparative Law,Ed., University of Georgia Press, Athens, Georgia (1993), 22.
13. William Tetley QC, Mixed jurisdictions : common law vs civil law (codified and uncodified) (Part I), Rev. dr. unif. 1999-3, p596
14. de Cruz, Peter, Comparative Law in a Changing World, 3rd edn 2007, 35, Kischel, Comparative Law (ref 1), 
15. Kershel 
16. Zweigert/Kötz, An Introduction to Comparative Law, 3rd edn 1998, reprint 2011, 299
17. Vernon Valentine Palmer, Mixed Jurisdictions Worldwide: The Third Legal Family, 2nd edition, Cambridge University Press, Online publication date :July 2012, p43, p72
18. T. B. Smith, “The Preservation of the Civilian Tradition in ‘Mixed Jurisdications’” in A. N. Yiannopoulos (ed.), Civil Law in the Modern World (Louisiana State University Press 1965), p. 5
19. F.P. WALTON, The Scope and Interpretation of the Civil Code, Wilson & Lafleur Ltée, Montreal
(1907), reprinted by Butterworths, Toronto (1980), with an introduction by M. TANCELIN, 1.
20. R. EVANS-JONES, “Receptions of Law, Mixed Legal Systems and the Myth of the Genius of Scots Private Law“ (1998), 114 L.Q.R. 228, 228.
21. Vernon Valentine Palmer, Mixed Jurisdictions Worldwide: The Third Legal Family, 2nd edition, Cambridge University Press, Online publication date :July 2012, p21
22. William Tetley QC, Mixed jurisdictions : common law vs civil law(codified and uncodified) (Part I), Rev. dr. unif. 1999-3, p601-604
23. Vernon Valentine Palmer, Mixed Jurisdictions Worldwide: The Third Legal Family, 2nd edition, Cambridge University Press, Online publication date: July 2012 p38
24. William Tetley QC, Mixed jurisdictions : common law vs civil law (codified and uncodified) (Part I), Rev. dr. unif. 1999-3, 604-606
26. William Tetley QC, Mixed jurisdictions : common law vs civil law(codified and uncodified) (Part I), Rev. dr. unif. 1999-3, 605-609