Certain persons are incapable of making a lawful will. For instance, those in the power of others are so absolutely incapable that they cannot make a testament even with the permission of their parents, with the exception of those whom we have enumerated, and particularly of children in power who are soldiers, and who are permitted by imperial constitution to dispose by will of all they may acquire while on actual service. This was allowed at first only to soldiers on active service, by the authority of the Emperors Augustus and Nerva, and of the illustrious Emperor Trajan; afterwards, it was extended by an enactment of the Emperor Hadrian to veterans, that is, soldiers who had received their discharge. Accordingly, if a son in power makes a will of his military peculium, it will belong to the person whom he institutes as heir: but if he dies intestate, leaving no children or brothers surviving him, it will go to the parent in whose power he is, according to the ordinary rule. From this it can be understood that a parent has no power to deprive a son in his power of what he has acquired on service, nor can the parent's creditors sell or otherwise touch it; and when the parent dies it is not shared between the soldier's son and his brothers, but belongs to him alone, although by the civil law the peculium of a person in power is always reckoned as part of the property of the parent, exactly as that of a slave is deemed part of the property of his master, except of course such property of the son as by imperial constitutions, and especially our own, the parent is unable to acquire in absolute ownership. Consequently, if a son in power, not having a military or quasimilitary peculium, makes a will, it is invalid, even though he is released from power before his decease.

1 Again, a person under the age of puberty is incapable of making a will, because he has no judgement, and so too is a lunatic, because he has lost his reason; and it is immaterial that the one reaches the age of puberty, and the other recovers his faculties, before his decease. If, however, a lunatic makes a will during a lucid interval, the will is deemed valid, and one is certainly valid which he made before he lost his reason: for subsequent insanity never avoids a duly executed testament or any other disposition validly made.

2 So too a spendthrift, who is interdicted from the management of his own affairs, is incapable of making a valid will, though one made by him before being so interdicted holds good.

3 The deaf, again, and the dumb cannot always make a will, though here we are speaking not of persons merely hard of hearing, but of total deafness, and similarly by a dumb person is meant one totally dumb, and not one who merely speaks with difficulty; for it often happens that even men of culture and learning by some cause or other lose the faculties of speech and hearing. Hence relief has been afforded them by our constitution, which enables them, in certain cases and in certain modes therein specified, to make a will and other lawful dispositions. If a man, after making his will, becomes deaf or dumb through ill health or any other cause, it remains valid notwithstanding.

4 A blind man cannot make a will, except by observing the forms introduced by a law of our imperial father Justin.

5 A will made by a prisoner while in captivity with the enemy is invalid, even though he subsequently returns. One made, however, while he was in his own state is valid, if he returns, by the law of postliminium; if he dies in captivity it is valid by the lex Cornelia.