[MARCIANUS libro quarto institutionum. ] §5.2.2.prHoc colore inofficioso testamento agitur, quasi non sanae mentis fuerunt, ut testamentum ordinarent.
[MARCIANUS in the fourth book of the Institutes.] Under this pretext, an action is brought against an undutiful will, as if they were not of sound mind when they drew up the will.
et hoc dicitur non quasi uere furiosus uel demens testatus sit, sed recte quidem fecit testamentum, sed non ex officio pietatis: nam si uere furiosus esset uel demens, nullum est testamentum.
And this is said, not as if a truly insane or demented person had made the will, but that he did indeed make the will in a regular manner, yet not in accordance with the duty of natural affection; for if he were truly insane or demented, the will is null.