[4] As an example, military campaigning removed personnel from circumstances in the city of Rome that facilitated the procedures for drawing up a last will and testament.
They were therefore exempt from the usual requirements, and wills written on the eve of battle could be held as valid.
[citation needed] A ius singulare was meant to advance the public interest as a matter of utility.
It required deft jurisprudence that preserved the norms of ius commune so that the exception did not become the rule,[5] with a clear understanding that the ius singulare was contra rationem, contrary to standard legal reasoning and thus not precedent.
[6] The principle of ius singulare was one of several techniques, among them a plethora of legal fictions, that enabled Roman law to evolve flexibly without overturning its authoritative texts or challenging the fundamental traditionalism of Roman society.