Point II. On the Effects of a Contract under a Mode

I. Notion. A contract under a mode is had when to a contract substantially complete there is added by one contracting party a burden to be fulfilled by the other from justice; as if someone gives another some sum of money for buying books, or sells someone a house on this condition, that he himself should dwell in it.

A contract under a mode is not had when a burden is not imposed, or is not imposed from justice, but is added only for the sake of stimulating; as if a father on the occasion of a feast gives something to his son, adding that he gives it for this end, that in the future he may study well.

A contract under a mode differs from a contract under a condition; for the latter depends, as to value, upon the condition, whereas a contract under a mode involves a new obligation being added to a valid contract.

Note 1. A mode contrary to the substance of the contract makes the contract void if consent is in reality attached to it, since it excludes consent with respect to the object of the contract.

Note 2. An impossible or base mode can be held as not added, unless it is established that consent was attached to it. For an impossible mode is presumed not to have been added seriously, but a base mode is imposed not by way of obligation but of allurement or seduction.

II. Effects. 1. One who accepts a contract under a possible and honest mode is bound from justice to fulfill the mode, as follows from what has been said. If it is culpably not fulfilled, restitution per se must be made to the amount of the interest in the mode being observed.

2. A mode not fulfilled does not render the contract rescindable. For the faculty or obligation of rescinding the contract would have to arise from the injury which neglect of the mode would involve. But from that injury there arises only the obligation of restoring to the amount of the interest in the mode being observed. But if the said injury could not be sufficiently repaired except by rescinding the contract and restoring things to their former state, per accidens, so to speak, the contract would become rescindable.

Often, however, there will not be a contract under a mode strictly so called, but from the mind of the contracting parties a mode, improperly so called, is added by way of a condition; if this is not fulfilled, the contract collapses or is rendered rescindable.¹

What the party whose interest is involved can do, with civil law considered, if the mode is not fulfilled, see in the Code of one's country.

¹ From cap. Verum, L. 4, tit. 5, De cond. appos., a donation for a pious cause does not collapse because of a mode not observed, unless the donor established this; but then a resolutory condition rather than a mode is had.