On the Estate of Nicostratus (16-17)

and, secondly, the laws, not only those which deal with consanguinity but also those which treat of testamentary disposition, are in favor of kinsmen. For the law allows no one to dispose of his own property if his reason is impaired by old age or disease or the other causes with which you are familiar; but by right of relationship the next-of-kin has an undisputed title to the property of a deceased person, whatever was the state of the latter's faculties.

Beside this, in order to believe in a will, you are obliged to rely on witnesses, by whom it is possible to be deceived—if this were not so, there would be no prosecutions for perjury—but when the claim is based on kinship, you act on your own authority, for the next-of-kin assert their right in accordance with the laws which you have laid down.