[IDEM libro septimo differentiarum. ] §35.1.52.prNonnumquam contingit, ut quaedam nominatim expressa officiant, quamuis omissa tacite intellegi potuissent nec essent offutura.
[BY THE SAME AUTHOR in the seventh book of Differences.] It sometimes happens that certain things expressed by name stand in the way, although, if they had been omitted, they could have been tacitly understood and would not have been harmful.
quod euenit, si alicui ita legatur: 'Titio decem do lego, si Maeuius Capitolium ascenderit'. nam quamuis in arbitrio Maeuii sit, an Capitolium ascendat et uelit efficere, ut Titio legatum debeatur, non tamen poterit aliis uerbis utiliter legari: 'si Maeuius uoluerit, Titio decem do': nam in alienam uoluntatem conferri legatum non potest.
This occurs if a legacy is left to someone in this manner: "I give and bequeath ten to Titius, if Maevius ascends the Capitol." For although it is within the discretion of Maevius whether he should ascend the Capitol and wish to bring it about that the legacy is owed to Titius, nevertheless it cannot be validly bequeathed in other words: "If Maevius wishes, I give ten to Titius"; for a legacy cannot be made dependent on the will of another.
inde dictum est: expressa nocent, non expressa non nocent.
Hence it has been said: "Things expressed harm, things not expressed do not harm."