MERCIMONIO (Simony/Traffic in Sacred Things). - It generally denotes any illicit traffic, whatever the source of its illegality. In a narrower sense, m. means illicit traffic because it is carried on in a forbidden matter; either because, by its intrinsic dignity, it is not compatible with the condition of a thing that may be traded, or because the law so provides for the protection of the public or private good.
Every contract concerning a forbidden object is null; therefore the mutual obligations that the contracting parties believed they were assuming, albeit freely, do not exist. However, after their fulfillment the parties may, in conscience, retain the advantages received, without any obligation of restitution. This is not by virtue of the previous bargaining, which always remains ineffective on account of invalidity, but by the very fact of the fulfillment of the contractual promises. Such fulfillment, in itself neither lawful nor obligatory, nevertheless verifies the condition on which depended the other innominate contract "do ut des," which would always be implicit in any illicit bargaining. By this atypical contract, the other party owes the counter-performance to the contracting party who in fact rendered the sinful work agreed upon, provided that it does not consist in intrinsically illicit work; for example, the agreed price.
It is clear that the concrete forms of m. can be very many. Within the scope of moral theology, however, the characteristic term chiefly calls to mind two: prostitution and the m. of Masses. The evident dignity of the matter, bartered in both forms of m., stigmatizes both. Even if positive law, deeming thereby to spare social life a greater evil, grants tolerance to prostitution, it does not thereby make it morally lawful either for the one who practices it or for the one who has recourse to it. Nevertheless, by the general doctrine set out above, the price of infamy may be retained quietly in conscience. This is also confirmed by a decree of the Sacred Penitentiary of 23 April 1822. The other aspects of this sad phenomenon are not of interest here (v. PROSTITUZIONE and the bibliography cited there).
For the m. of Masses, v. ELEMOSINE.
Leonardo Azzolini