However, the long persistence of the prohibition of the canon law in relation to interest, even with the refuge afforded by the introduction of the rent-purchase system, and of dormant partnerships (_Commanditen_) etc., so common in the sixteenth century,[191-11] would be unintelligible, if, contemporaneously, the Jews did not carry on an important and somewhat free trade in capital,[191-12] precisely as the Armenians, Hindoos and Jews do in the Mohammedan world of to-day. [Footnote 191-1: The apostolic canons and several decrees of councils of the fourth century prohibit the taking of interest by the clergy. A Spanish provincial council dared, in 313, to extend the prohibition to the laity. Pope Leo I. condemned the taking of interest by the laity also, but only in the form of a moral law. (443.) The synod of Constantinople (814) punished the violation of the prohibition with excommunication. See _Thomas Aquin._ (ob. 1274.) De Usuris, in the Quæstiones disputatae et quod libetales. The canon law, however, always permitted delay-interest (_Verzugszinsen_), and Gregory IX, allowed _justa et moderata expensa et congruam satisfactionem damnorum_ to be taken into account, (c. 17, X.) De Fora Comp. II, 2. A tacit recognition of the productiveness of capital is to be found in c. 7, X. De Donatt. inter. Virum. cett. IV, 20; and the later schoolmen, _Antonin_ and _Bernhardin_, (ob. 1459 and 144) are pretty clear on the point. But _Albertus Magnus_ had already recognized the _damnum emergens_ and _Thomas Aquinas_ the _lucrum cessans_ as causes of interest. (Tübinger Zeitschr., 1869, 151, 159, 161.) The essentially modern character of Roman law, which, in the form it has finally assumed, is in harmony with a high development of national economy, accounts for the fact that the glosse of _Accursius_ relying on _Irnerius_ and _Bulgarus_ entirely ignores the prohibition of interest. For a similar reason, in the 16th century, _Donellus_ and _Cujacius_ stand entirely on Roman ground. In the interval, indeed, men like _Bartolus_ and _Baldus_ were not disquieted by the canon law. (_Endemann_, Studien in der Römisch-Canonischen Wirtchaftsund Rechtslehre, I, 18, 27 seq. 61.) Compare the rich historical material in _Salmasius_, De Usuris, 1638; De Modo Usurarum, 1639, and De Mutuo, 1640.] [Footnote 191-2: _A. Thierry_, Lettres sur l'Histoire de France, éd. 2., 248 ff.]