This blog post examines how the tradition of Roman law commentary, originating in 12th-century Bologna, led to a new scholarly transformation. It traces the flow from the authority of the Digesten, changes in interpretive methods, to Leibniz’s critical approach.
Serious study of the Corpus Juris Civilis began in the 12th century, centered in Bologna. At that time, this legal text was recognized as possessing absolute authority, even being called ‘written reason,’ and among its parts, the Digesta section drew the greatest interest from scholars. The Digesta contained a compilation of diverse doctrines excerpted from the writings of prominent jurists of the Roman era. Early legal scholarship focused its primary effort on accurately understanding this content, and a critical stance toward Roman law was almost taboo.
This scholarly tradition culminated in the compilation of standard commentaries by the mid-13th century. Thereafter, the focus of legal studies shifted to the practical application of Roman law in legal practice. By the 16th century, scholars moved beyond blind faith in the Digesten and began treating it as historical source material, attempting new approaches unbound by the commentaries’ interpretations. This trend became established and familiar in later periods. Leibniz, a 17th-century scholar, also critically engaged with Roman law materials to initiate new discussions.
The following is an excerpt from Paulus’s work included in the Digest. Felix had successively granted mortgages on his estate to Eutychiana, Turbus, and Titius, establishing the substantive legal relationships. However, Eutychiana failed to prove her priority claim in her lawsuit against Titius and lost the case; the judgment became final. Subsequently, a new dispute arose between Turbus and Titius over the priority of the mortgage rights, leading to litigation. The question then arose: should Titius, who had prevailed against Eutychiana, be considered to have priority over Turbus? Or should Eutychiana be deemed non-existent, placing Turbus’s rights ahead of Titius’?
Some argued that Titius should take precedence. However, Paulus finds such a conclusion highly unjust. Suppose Eutychiana lost to Titius due to poor defense. Does the effect of the judgment Titius obtained against Eutychiana truly extend to Turbo? And if Turbo subsequently prevails in a lawsuit against Titius, would that judgment then affect Eutychiana? Paulus says no. The fact that a third-ranked claimant excludes the first-ranked claimant does not make the third-ranked claimant first-ranked. A judgment between litigants does not benefit or harm those not involved in that particular lawsuit. The judgment in the first lawsuit does not resolve all situations; the rights of other mortgagees remain ‘untouched.’
Leibniz sought to re-examine the priority of this ‘untouched’ element. He first organized the matter as follows. Under Roman law, mortgages on the same property are prioritized according to their order of establishment. Therefore, first, Eutychiana’s mortgage, established first, holds the highest priority and takes precedence over Turbo’s mortgage. Second, Turbo’s mortgage, established second, takes precedence over Titius’s mortgage. However, third, a legal relationship established by a final judgment must be treated as true, so Titius’s mortgage takes precedence over Eutychiana’s mortgage. Here, the first and third points conflict, but due to the effect of the final judgment, the third must prevail. Therefore, ultimately, only the second and third points need be validly considered, and combining these two allows the order of precedence to be simply resolved.
Paulus stated that Eutychiana cannot regain first priority, yet he also could not acknowledge that Titius takes precedence over Turbus, nor that Turbus takes precedence over Eutychiana. Regarding this, Leibniz criticized Paulus’s view that one cannot definitively assert Turbus’s superiority over Eutychiana. If Turbo precedes Titius and simultaneously Titius precedes Eutychiana, then it is logically natural for Turbo to precede Eutychiana. Moreover, placing Turbo after Titius violates the principle that the effect of a judgment should not extend to those not involved in the lawsuit. This ultimately fails to avoid precisely the situation Paulus sought to prevent, making such a placement unacceptable.
Leibniz argues that while this conclusion pushes the rank back two places due to a single loss, it is by no means unjust. He contends that imposing a double disadvantage on the party who mishandled the lawsuit is preferable to imposing a single disadvantage on another party who did nothing wrong. He even added a witty comment suggesting that Paul’s very status as a wise man might be questionable.
Leibniz’s work, alongside the widespread influence of Roman law at the time, well illustrates the era’s atmosphere where scholars freely approached and attempted critical discussions despite its authority. Following the 18th century, this tradition of Roman law research laid the foundation for the subsequent development of new legal theories and legal systems.
