Introduction
While researching the evolution of the principle of change of circumstances for my PhD thesis, I was intrigued by a peculiar coincidence – Bulgaria, Italy, and the United States embraced doctrines addressing hardship in contract during the same historical period. The principle of economic onerosity (stopanska neponosimost) paved its way to the Bulgarian Law on Obligations and Contracts of 1950, albeit with a limited scope – Article 266, paragraph 2 applies only to manufacturing contracts. A general principle on hardship (onerosità sopravvenuta) was enshrined in the Italian Civil Code of 1942 (see Articles 1664 and 1467). Section 2-615 of the Uniform Commercial Code, first published in 1952, defined the notion of impracticability in a sales contract.
In the aftermath of World War I, countries faced serious economic challenges, including drastic inflation. Therefore, the timing of the introduction of principles on change of circumstances in Bulgaria, Italy and the United States is not surprising. The coincidence, however, sparked my curiosity from a comparative standpoint:
—First, Germany and France, which have had a tremendous influence on both Bulgarian and Italian law, enacted rules on change of circumstances only recently. While German judges developed solutions in case law based on scholarly theories to provide relief to aggrieved parties in the aftermath of World War I, Germany codified such general principle in Section 313 of its Bürgerliches Gesetzbuch only in 2001 (see Basil S Markesinis, Hannes Unberath and Angus Johnston, The German Law of Contract: A Comparative Treatise (2nd edn, Hart Publishing 2006) 326–342). Meanwhile, France introduced the concept of imprévision in civil contracts as Article 1195 in its Code civil as late as 2016 (see Catherine Pédamon, ‘The Paradoxes of the Theory of Imprévision in the New French Law of Contract: A Judicial Deterrent?’ [2017] 112 Amicus Curiae: Journal of the Society for Advanced Legal Studies 10–17).
—Second, English law, which is considered the mother of common law jurisdictions, does not recognise the notion of impracticability (commercial impossibility) in contract law. In Tennants (Lancashire) v CS Wilson, Earl Loreburn famously underlined: “The argument that a man can be excused from performance of his contract when it becomes ‘commercially impossible’… seems to me a dangerous contention which ought not to be admitted unless the parties have plainly contracted to that effect” ([1917] AC 495, 510).
—Third, during the Cold War, mainstream comparative taxonomies placed Bulgaria, Italy, and the United States in three distinct families – Socialist law, Romanistic Law, and Anglo-Saxon Law. At first glance, a connection between these jurisdictions is unlikely. Moreover, comparisons among what appears to be a random selection of jurisdictions are discouraged, even though academic attitudes have recently been shifting – namely, Zweigert and Kötz encourage scholars to compare mother systems or mothers with their daughter systems (Konrad Zweigert and Hein Kötz, Introduction to Comparative Law (Tony Weir tr, 3rd edn, Clarendon Press 1998) 41).
In an article titled ‘Legal Change and the Role of the Scholar: Scratching beneath the Surface of Comparative Taxonomies’ which was published in Studia Iuridica earlier this month, I demonstrate how examining the biographies and opinions of three scholars – Lyuben Dikov, Filippo Vassalli, and Karl Llewellyn – may not only provide insights on how law develops, but may also expose barely visible, yet fascinating links between Bulgarian, Italian, and US law. These links appeared because of intellectual exchanges during the Interwar period. In other words, there are grounds to believe that the peculiar coincidence I noted regarding the doctrine of hardship may not be an accident at all – the similarities between Bulgarian, Italian, and US law may have been ignored because of pre-understandings and generalisations about legal systems imposed by mainstream comparative taxonomies.
Of course, ideological concerns may have taken their toll, too. One has to be conscious of the complex political reality during the Interwar period and the Cold War. Between 1922 until 1943, Benito Mussolini led a fascist regime in Italy – it has been noted that “[t]he common law tradition was treated with contempt…” at the time (see Elisabetta Grande, Rodrigo Míguez Núñez, and Pier Giuseppe Monateri, ‘The Italian Theory of Comparative Law Goes Abroad’ (2021) 1 The Italian Review of International and Comparative Law 5, 6). Proper intellectual dialogue between Italy and the US intensified later (see, for instance, the work of the great John Henry Merryman: JH Merryman, ‘The Italian Style I: Doctrine’ (1965) 2 Stanford Law Review 239–65; JH Merryman, ‘The Italian Style II: Law’ (1966) 3 Stanford Law Review 396–437; JH Merryman, ‘The Italian Style III: Interpretation’ (1966) 4 Stanford Law Review 583–611). Meanwhile, during the Interwar period, Bulgaria maintained a close relationship with both Italy and Germany because of historical ties; however, following World War II, it became a communist country, which determined a very different direction for comparative law and undermined prior dialogues with countries in Western Europe.
Three Intellectual Giants of Their Time
Lyuben Dikov, Filippo Vassalli, and Karl Llewellyn were leading scholars in their respective jurisdiction. Dikov was Bulgaria’s leading scholar in civil and commercial law in the 1920s and 1930s – he may be deemed the main influence behind Bulgaria’s Law on Obligations and Contracts (LOC). Not only are LOC’s suspected drafters his students, but many of his ideas were codified in the LOC of 1950 (see Radosveta Vassileva, ‘Shattering Myths: The Curious History of the Bulgarian Law of Obligations’ (2019) 82 Studia Iuridica 309–27). Vassalli is one of the “fathers” of the Codice Civile – he has personally admitted that he has written two-thirds of the code (see Giovanni Chiodi, ‘Filippo Vassalli’ in Enciclopedia italiana di scienze, lettere ed arti. Il contributo italiano alla storia del pensiero – Diritto (Treccani 2012) 563-567). Llewellyn is often presented as the principal author of the Uniform Commercial Code (UCC) because of his important contributions to its planning and drafting (William Twining, Karl Llewellyn and the Realist Movement (2nd edn, Cambridge University Press 2012) 271).
These talented scholars belonged to the same generation – Dikov was born in 1895, Vassalli – in 1885, and Llewellyn – in 1893. More importantly, they exchanged ideas with intellectual circles in proximity. Dikov defended his PhD in law at the University of Göttingen in 1922 (Das Institut des Strohmannes (die vorgeschobene Person) im bürgerlichen Rechte, Doctoral Thesis, Göttingen 1922). While he was fascinated with German law and followed developments in Germany closely, he kept in touch with Italian scholars, too. For instance, he published articles in Rivista internazionale di filosofia del diritto, which was edited by Giorgio del Vecchio, a leading authority at ‘La Sapienza’ University in Rome (Il Diritto civile dell’avvenire’ (1931) 11 Rivista internazionale di filosofia del diritto 153–180; ‘Norma giuridica e volontà privata’ (1934) 14 Rivista internazionale di filosofia del diritto 681–706).
In parallel, in 1930 Vassalli was appointed as professor at the University of Rome. As accounted by contemporary Italian scholarship, he was well acquainted with German literature. Moreover, he was involved in the work of the International Institute for the Unification of Law (UNIDROIT) in Rome (see Giovanni Chiodi, ‘Filippo Vassalli’ in Enciclopedia italiana di scienze, lettere ed arti. Il contributo italiano alla storia del pensiero – Diritto (Treccani 2012) 563–567).
Llewellyn, one of the fathers of American legal realism, has connections to both Germany and Italy, similarly to Dikov. He was visiting professor in Leipzig for two academic years –1928-1929 and 1930-1931 during which he engaged with the writings of German scholars (Michael Ansaldi, ‘The German Llewellyn’ (1992) 58 Brooklyn Law Review 705, 710–717). It is also known that he befriended Ernst Rabel who invited him to a meeting of the UNIDROIT Institute in 1932 to discuss the project of creating common principles of international sales law (See Peter Winship, ‘Karl Llewellyn in Rome’ (1998) 3 Uniform Law Review 725–738).

Common Intellectual Interests and Views about the Future of Contract
In view of the above, it may not be surprising that Dikov, Vassalli, and Llewellyn had common research interests, intellectual anxieties, and hopes for the development of law. Of course, one has to be sensitive to the particularities of context, too – these scholars had to conform with different political regimes. However, it is already revealing that Vassalli was not only the father of the Codice Civile, but also the head of the group tasked with defascising the Codice Civile after the fall of Benito Mussolini.
In my article, for instance, I explain that Dikov, Vassalli, and Llewellyn had similar criticism towards liberal individualist values – they viewed contract as part of a greater whole (such as society) instead of a mere promise or an agreement. One should, of course, remember that during the Interwar period organic social theories flourished. I was fascinated to discover that Dikov and Llewellyn published papers resonating similar concerns about the future of contract in the exact same year (Karl Llewellyn, ‘What Price Contract?—An Essay in Perspective’ (1931) 40 Yale Law Journal 704; L Dikov, ‘Il Diritto civile dell’avvenire’ (1931) 11 Rivista internazionale di filosofia del diritto 153–180). Llewellyn asserted: “Contract is of course not outside of, but a part of, anything that can be denominated ‘society’. The question is: what part does it play in the whole; and what effects flow from the part being played in that particular way” (see page 716 of his article). In turn, in his article, Dikov argued that the French Civil Code could not serve as “a model for future civil law” and that scholars had to think of a new model, which, for him, had to be based on organic social theory. While Dikov was well acquainted with the work of Léon Duguit, he was worried that his criticism for liberal individualism was not radical enough. In principle, Dikov believed that the social contract had to be reconsidered – in his view, it was society that preceded the individual rather than the latter. He envisioned people as being dependent on one other just like the cells of an organism – thus contract was not an agreement, but a legal relationship which could only exist within an organism and had to be beneficial for the entire organism (the whole) (see Radosveta Vassileva, ‘Contract Law and the Social Contract: Rethinking Law Reform in the Field of Contract Law from the Perspective of Social Contract Theory,’ Pravni život (Legal Life), 2016, Issue 11-Volume III, Year LXV, pp. 267–286). It is interesting that Dikov’s views were published in France (L Dikov, ‘L’évolution de la notion de contrat’ in Etudes de droit civil à la mémoire de Henri Capitant (Dalloz 1939) 201-18).
Vassalli was milder in his criticism against liberal individualism, compared to Dikov and Llewellyn, but he was aware of the need for a “deeper consideration for the social element, and above all, the problems affecting the working masses” (Filippo Vassalli, ‘Arte e vita nel diritto civile’ in Studi Giuridici. Vol. 2 (Foro Italiano 1939) 451). He also admitted that the “organic link” between the individual and society was at the centre stage of the Italian Civil Code of 1942 (Filippo Vassalli, ‘Motivi e caratteri della codificazione civile’ in Studi Giuridici. Volume III (Giuffrè 1960) 615).
It is also interesting that these three scholars pondered the role of judges, including the need to escape the rigidity of rules. Dikov contended that if a given rule led to unsatisfactory results which were not known or were not well thought out by the legislator, the judge should have the freedom to adjust the rule (Lyuben Dikov, ‘The Essence of Adjudication’ in The Modification of Contracts by the Judge (first published 1923, Feneya 2010) 144). Vassalli shared the belief that a rule only gained value thanks to literature and case law: “…a legal rule is not valuable by itself but for the literature and jurisprudence which promotes it: a civil code is just a point of departure for further development of [legal] thought” (Filippo Vassalli, ‘Motivi e caratteri della codificazione civile’ in Studi Giuridici. Volume III (Giuffrè 1960) 631). Llewellyn, in line with the spirit of the American realist movement, advocated for a case-by-case approach: “We have discovered that rules alone, mere forms of words, are worthless. We have learned that the concrete instance, the heaping up of concrete instances, the present, vital memory of a multitude of instances, is necessary in order to make any general proposition, be it rule of law or any other, mean anything at all. Without the concrete instances the general proposition is baggage, impedimenta, stuff about the feet” (Karl Llewellyn, The Bramble Bush (Oceana Publications 1951) 12).
Commitment to Similar Principles of Contract
In light of their macro views on the need to reconsider contract to account for its role in society and their calls to escape the straitjacket of rules, it is not surprising that the three scholars were committed to introducing to legislation principles providing judges with more flexibility, such as the doctrine of hardship. It should be remembered that the main resistance to such a doctrine came from those committed to liberal individualist values, such as the sanctity of contract and freedom of contract and the belief that the role of the judge in relation to contract was primarily limited to its interpretation. Advocates for the doctrine of hardship demanded termination and/or modification of contract by the judge, without the consent of both parties, which could be viewed as a radical departure from liberal individualist values. In other words, not blindly subscribing to liberal individualist beliefs, Dikov, Vassalli, and Llewellyn were confronted with unique windows of opportunity to facilitate paradigmatic shifts in values in the law because of their roles in drafting legislation and/or inspiring those drafting legislation.

It is documented, for instance, that Llewellyn drafted Section 87 of the Revised Sales Act, incorporated as Section 2-615 of the UCC, which recognises impracticability in the contracts of sale (William Hawkland, ‘The Energy Crisis and Section 2-615 of the Uniform Commercial Code’ (1974) 79 Commercial Law Journal 75, 77). Dikov published a series of articles and chapters advocating for the introduction of the doctrine of economic onerosity in Bulgarian legislation. He was particularly fascinated by German case law and doctrinal writing pertaining to hardship, but he believed that a more radical approach was necessary – namely, rethinking what contract is and should be. (L Dikov, ‘Norma giuridica e volontà privata’ (1934) 14 Rivista internazionale di filosofia del diritto 681–706; L Dikov, ‘The Evolution of Contract’ (1938) 33 Annuaire de l’Université de Sofia 437, translated in French: L Dikov, ‘L’évolution de la notion de contrat’ in Etudes de droit civil à la mémoire de Henri Capitant (Dalloz 1939) 201-18; L Dikov, ‘Die Abänderung von Verträgen den Richter’ in Hedemann-Festschrift (Jena 1938)). Moreover, Dikov wrote an article passionately presenting the Italian Civil Code of 1942 as an extraordinary achievement in terms of quality and drafting (Lyuben Dikov, ‘The New Italian Civil Code’ (1942) 37 Annuaire de l’Université de Sofia 57). Thus, while striking that those developing a communist LOC borrowed from a country with a different ideology, it is not accidental that Dikov’s proposals were taken on board by LOC’s drafters. Bulgaria’s LOC follows closely the section on obligations in the Italian Civil Code of 1942 – in fact, Bulgaria’s provision on economic onerosity is almost a verbatim copy of Article 1664 of the Italian Civil Code (Radosveta Vassileva, Bulgarian Private Law at Crossroads (Intersentia 2022) 77–78).
Recent historical research on the work of Vassalli has revealed that Italy was on its way to embracing the principle of onerosità sopravvenuta as early as 1930. While Vassalli believed that legislation enacted ad hoc was better placed to address contractual imbalances due to supervening events, he seems to have conceded to a general principle on hardship, as illustrated by the provisions enacted in the Codice Civile (Giovanni Ferri, Filippo Vassalli O Il Diritto Civile Come Opera d’Arte (CEDAM 2002) 58).
Overall, from a bird’s-eye view, enshrining the principle of change of circumstances in Bulgaria, Italy, and the US can be seen as complex, nuanced transplantations of Germanic ideas in very different political contexts. Yet, a generalised description would not do justice to the reality of how ideas travel and pave their way to legislation in practice. While German judges were the first to provide relief in case of supervening onerous performance in the aftermath of World War I, these ideas were codified in other countries much earlier than in Germany thanks to jurists following the debates in Germany, Italy, and elsewhere, who were also reacting against the liberal individualist values that were so dear to English and French law at the time. Here, for the sake of clarity, it should also be mentioned that the first Bulgarian LOC of 1892 was a replica of the Italian Civil Code of 1865, which, in turn, copied the French Civil Code. In other words, both Bulgarian and Italian law were rebelling against the rigidity of the French Civil Code, while US law departed even further from English law.
Lessons for Comparative Law
As explained above, in the same historical period (the Interwar period), Bulgarian, Italian, and US law experienced paradigmatic shifts in contractual values, which crystallised in legislation shortly thereafter. They can be better understood if one researches the biographies and intellectual interests of the scholars who played an important role in facilitating them, such as Lyuben Dikov, Filippo Vassalli, and Karl Llewellyn.
Sadly, comparative literature is prone to embracing generalisations and imposing pre-understandings. It is often ignored that legal change is induced by small groups of individuals who are often scholars. Exploring their backgrounds and influences may hold the key to a more in-depth understanding of the evolution of the law and the peculiar ways in which legal ideas cross geographic and ideological borders. Learning more about the intellectual circles to which academics belonged and considering the views they expressed in academic writing and beyond may shed more light on the reasons why a given principle paved its way to legislation. Such inquiries may also expose little-known connections between legal systems which, according to comparative taxonomies, have little or even nothing in common.
Of course, one can find examples of scholars who have not been deterred by mainstream comparative wisdom and have engaged in meaningful comparisons between the US and Italy. However, one may also wonder if there are many stories that have remained untold because of the prejudices of comparative law as a discipline and/or because of political biases and stigmas. It is already revealing that in recent years scholars have started shedding light on “the forgotten influence” of Italian law on US law (see, for instance, John D Bessler, ‘The Italian Enlightenment and the American Revolution: Cesare Beccaria’s Forgotten Influence on American Law’ (2017) 1 Hamline Journal of Public Law and Policy 1–185). It is also unfortunate that literature documenting the relationship between Bulgarian and Italian law, which continued throughout communism, is scarce.
Finally, it is difficult to believe that the subtle connection between Bulgarian, Italian and US law from the Interwar period is an isolated case – in principle, substantive comparative research on these jurisdictions or other jurisdictions, which are rarely studied together, may showcase the less-known patterns of legal change and shed better light on the decisive role of legal scholars in conditioning the evolution of the law when confronted with unique windows of opportunity. It may also further challenge the illusion of pre-understanding which mainstream comparative taxonomies impose on comparative scholars.
Posted by Dr Radosveta Vassileva, Middlesex University
This piece belongs to Season 2 of the “Cross-jurisdictional dialogues in the Interwar period” series dedicated to less-known legal transfers which have had a palpable impact on the advancement of the law. The Interwar period was a time of disillusionment with well-established paradigms and legislative models, but also a time of hope in which comparative dialogue and exchange of ideas between jurisdictions thrived. The series is edited by Prof Yseult Marique (Essex University) and Dr Radosveta Vassileva (Middlesex University). To access the other pieces from this series, either select the ‘Interwar Dialogue’ category or click on the #Series_Interwar_Dialogue tag on the BACL Blog.
Suggested citation: R Vassileva, ‘Lyuben Dikov, Filippo Vassalli, and Karl Llewellyn: Three Scholars Who May Hold a Key to Understanding Some Peculiar Similarities between Bulgarian, Italian, and US Law’, BACL Blog, available at https://wp.me/p80U0W-1zN
