LOSS OF PROFIT. — This expression denotes the diminution of assets resulting from the failure to acquire goods which, had a certain event not occurred, would have been acquired. A diminution of assets may in fact arise either from the loss of something already possessed or from the failure to acquire something that one would certainly have come to possess. The first form is called domnum emergens; the second lucrum cessans.
A diminution of assets may be considered both from the standpoint of the person who causes it and from that of the person who suffers II. In the latter case, it may be of particular interest as a legitimizing cause. L. c. may, for example, legitimize an increase in the price of what constitutes the objectively just share, lending at interest, postponing repayment, or omitting the Mass on a feast day. From the first standpoint, that is, considering the diminution of assets from the perspective of the person who causes it, the obligation of restitution must be emphasized.
There is no doubt that whoever culpably causes damage is obliged to repair it in full, including with regard to l. c. This follows from natural law and is expressly affirmed by the civil codes (cf., for the Italian Civil Code, art. 1223).
Nevertheless, a difficulty immediately arises. How is l. c. to be assessed exactly? How can one determine precisely what a person would have acquired if a particular event had not occurred? As can be seen, one enters the realm of the future contingents, that is, the realm of those conditional developments of history which only God can know with certainty. Human beings cannot go beyond conjecture, based on what ordinarily happens. For these reasons, l. c. can be assessed only on the basis of statistical criteria, derived from the customary course of events. One must consider what ordinarily happens, disregarding both exceptionally fortunate and exceptionally unfortunate cases. The Italian Civil Code states that “l. c. is assessed by the judge through an equitable evaluation of the circumstances of the case” (art. 2056).