Haec vulgo iactata super id, quod nullo auctore certo firmantur, prompte refutaveris. quis enim mediocri prudentia, nedum Tiberius tantis rebus exercitus, inaudito filio exitium offerret, idque sua manu et nullo ad paenitendum regressu? quin potius ministrum veneni excruciaret, auctorem exquireret, insita denique etiam in extraneos cunctatione et mora adversum unicum et nullius ante flagitii compertum uteretur? sed quia Seianus facinorum omnium repertor habebatur, ex nimia caritate in eum Caesaris et ceterorum in utrumque odio quamvis fabulosa et immania credebantur, atrociore semper fama erga dominantium exitus. ordo alioqui sceleris per Apicatam Seiani proditus, tormentis Eudemi ac Lygdi patefactus est, neque quisquam scriptor tam infensus extitit, ut Tiberio obiectaret, cum omnia alia conquirerent intenderentque. mihi tradendi arguendique rumoris causa fuit ut claro sub exemplo falsas auditiones depellerem peteremque ab iis quorum in manus cura nostra venerit, ne divulgata atque incredibilia avide accepta veris neque in miraculum corruptis antehabeant.
(Tacitus, Ann. 4.11)
This was bandied about in public, but, beyond the fact that it is affirmed in no reliable author, you can readily refute it. What man of average prudence—still less Tiberius, practiced as he was in great affairs—would have offered extermination to a son unheard, and that too with his own hand and no recourse for repentance? Would he not rather have racked the server of the poison, searched out its initiator, and finally, given the innate hesitancy and delay with which he treated even outsiders, treated his one and only, who had been discovered in no outrage, with the same? Yet, because Sejanus was considered the deviser of every act, it was owing to Caesar’s excessive affection for him and to everyone else’s hatred of them both that even the most monstrous fantasies were believed—report being always more frightful in relation to one’s departed masters. Besides, the stages of the crime were betrayed by Sejanus’ Apicata and disclosed by the torturing of Eudemus and Lygdus; nor did any writer at all prove so hostile that he cast this imputation at Tiberius, though they raked up and aimed everything else. In my case the reason for transmitting and criticizing the rumor was that on the basis of a resounding example I might dispel false hearsay and ask of those into whose hands my work comes that they should not be hungry to accept well publicized incredibilities nor prefer them to what is genuine and uncorrupted by the miraculous. (tr. Anthony John Woodman)