The medieval system had been a rights-based system. Each member of that society had a particular place that determined rights, obligations, and a well-defined role. It is a familiar but erroneous portrait of the medieval era that depicts its society as uniform and colorless. Rights-based systems can in fact yield enormous diversity, because though conformity may be enforced by law, it is not necessarily enforced by that most pitiless of masters, the individual ambition; thus such systems often encourage creativity, as the natural exuberance of individuals attempts to circumvent the rigidity of their assigned roles and the received wisdom. Yet these systems often strike us as irrational in practice because they do not attempt to match talent and performance with role. Perhaps that is why contemporary philosophers today who urge us to adopt rights-based systems often must resort to hypothesized situations like the Rawlsian veil of ignorance, behind which each person must choose a distributive system he or she would prefer without knowing what particular person one turned out to be.
What rights-based systems reject, then, is rationality applied to the contingent situation. Thus the Franciscans imprisoned Roger Bacon for his scientific speculations; the Dominicans preached crusades against the cultivated nobles of Toulouse; the Benedictines erased masterpieces of classical literature in order to copy litanies, and sold pieces of parchment for charms. And even though Aquinas, Duns Scotus, and William of Ockham were rigorous logicians, only Aquinas applied this rigor to the analysis of their political condition.
The spirit of the Renaissance, by contrast, was quickened by curiosity, piqued of course by the recovery of classical models that provided an alternative to the medieval paradigms, but driven relentlessly by a need for inquiry into the place of temporal man himself. Copernicus and Galileo; Vesalius and Harvey; Leonardo and Michelangelo; Petrarch and Boccaccio—all had this in common: a desire to see man's contingent situation as it is. This draws the light of rationality back onto the viewer. In the medieval period, there had been a universal system of customary law, based on the rights of inheritance, charters, and grants. Customary law is the common law of practices. We are inclined today to think of common law as generated by courts, but this is really an abbreviation: common law is simply the customary law of the judiciary; it grows and is modified by the exercise of court practices. The medieval period was almost entirely ruled by a kind of common law, but the generating institutions of that law were seldom judicial courts.
When these institutions began to malfunction—as, for instance, when the introduction of a money economy broke down the rights-relations of lord and vassal with regard to military service—and new practices developed (such as the professional, mercenary army), the questioning figures of the Renaissance tried to design institutions that would improve on the merely customary (for example, Machiavelli's plan for a conscripted militia drawn from the Florentine population).
Precisely because the inherited institutions were rights-based, they could not promote new arrangements that were violative of the customary methods. A prince alone could not rewrite the constitutional rules of his society's governance to meet his own needs; that would require an institution that objectified the needs of the prince but was distinct from the prince himself [— the princely state].
— Philip Bobbitt, The Shield of Achilles, pp. 87-88
