Marcianus, Trusts, Book VII. There is no longer any room for doubt that heirs can be appointed under the following condition, namely: “If they wish to be heirs, and if they do not wish to be, another, who seems to be acceptable, shall be substituted for them.” In this instance, it has been denied that it is necessary to disinherit a son under the contrary condition; in the first place, because this is only required when the condition is in his power, or he is the heir of his father, and its fulfillment is dependent upon some outside influence and must be awaited; second, because no matter what kind of a condition has been imposed, the son should be disinherited under the contrary condition, and in the case stated disinheritance cannot possibly take place; and certainly if it were expressed in words it would be absurd, for what other terms can be conceived which would be contrary to this condition: “If he is willing, let him be my heir”, than these: “If he is unwilling to be my heir, let him be disinherited”? It is evident to every one that such a provision is ridiculous. 1It does not seem to be foreign to the subject to add here, by way of supplement, that when heirs are appointed under the condition, “If they wish to be heirs”, they should not be permitted to reject the estate for the reason that where they are appointed under this condition they are not necessary heirs, but become such voluntarily. Nor are they entitled to the right to reject the estate under other conditions which they are able to comply with, and have fulfilled.

Marcianus, Trusts, Book VII. Our Emperor, Antoninus Pius, in order that the last wills of his soldiers might in every respect be considered valid, where an appointed heir and his substitute died suddenly before entering upon the estate, ordered that those to whom freedom and the estate had been left under a trust, by soldiers, should become free and be heirs, just as if they had received both of these bequests directly. Moreover, where slaves, by means of a trust, had acquired their freedom and an estate from a civilian, and the appointed heir and his substitute had also died suddenly, he held that this was sufficient for the confirmation of their freedom.