Canon law’ was the law governing the Church, and during the early Christian era and the Middle Ages the intertwining of Church and state often meant that canon law and state law were one and the same. Early canon law consisted of papal decretals, decrees of church councils, and the writings of the Church Fathers. We have seen that later canon law also incorporated much of the Roman law. But canon law also included something else basically pernicious: the decrees and regulations (‘capitularies’) of the Carolingian Empire in the latter eighth and ninth centuries.
From the fifth to the tenth centuries, the economic and political chaos of the Dark Ages prevailed throughout Europe, and there was consequently little or no room for the development of political, legal or economic thought. The only exception was the activities of the Carolingian Empire, which burgeoned in western Europe. The most important Carolingian Emperor was Charlemagne (742–814) and his rule devolved on to his successors during the remainder of the ninth century. In capitulary after capitulary, Charlemagne and his successors laid down detailed regulations for every aspect of economic, political and religious life throughout the empire. Many of these regulations became incorporated into the canon law of later centuries, thereby remaining influential well after the crumbling of the Carolingian Empire itself.
Charlemagne built his despotic network of regulations on a shaky foundation. Thus the important Church council of Nicaea (325) had forbidden any clergymen from engaging in any economic activities leading to ‘shameful gain’ (turpe lucrum). In his council at Nijmegen (806) Charlemagne revived, greatly broadened and imposed the old doctrine of turpe lucrum. But now the prohibition was extended from the clergy to everyone, and the definition broadened from fraud to all greed and avarice, and included any disobedience of Charlemagne's extensive price regulations. Any market deviations from these fixed prices were accused of being profiteering by either buyers or sellers and hence turpe lucrum. As a corollary, all speculative buying and selling in foodstuffs was prohibited. Moreover, in foreshadowing the English common law prohibition of ‘forestalling’, any sale of goods outside and at higher prices than the regular markets was prohibited. Since the English common law was motivated, not by a misguided attempt to aid the poor but in order to confer monopoly privileges on local owners of market sites, it is highly probable that Charlemagne, too, was trying to cartelize markets and confer privileges on market owners.
Every arbitrary price decree of the Carolingian officialdom was of course revered by the Carolingians as the ‘just price.’ Probably this coerced price was often near what had been a customary or current price in the neighbourhood; otherwise it would be difficult to conceive how the Carolingian officials would discover what price was supposed to be just. But this meant a futile and uneconomic attempt to freeze all prices on the basis of some past market status quo.
The problem, then, is that later canon law incorporated the idea of the just price as being the state-decreed price. The banning of any price higher than the current market price was reimposed by the late Carolingian Emperor Carloman in 884, and incorporated into the canon law collection of Regino of Prum in 900, and over a century later into that of Burchard of Worms.
Remarkably, the two contradictory legal strains: the laissez-faire theme of the Theodosian Code, and the statist Carolingian motif, both found their way into the great collection at the basis of the medieval discipline of the canon law: that of Bishop Ivo of Chartres, at the turn of the twelfth century. There, in the same collection, we find the view that the just price is any price voluntarily arrived at by buyer and seller, and also the contradictory view that the just price is one decreed by the state, especially if it be the common price in general markets.