Ronald Syme,
Tacitus, Vol. II (1958; rpt. Oxford: Clarendon Press, 1997), pp. 563-564:
Tone and language may be deceptive. The writer has wrapped himself in his subject. None of the Roman historians can refuse an allegiance to tradition. Conformity does not prove them narrow and conservative. Tacitus allows the eminent lawyer Cassius Longinus to expound an impressive defence of old Roman practices—Cassius is convinced that all change is for the worse.1 The personality of Cassius (but not perhaps his argument in this instance) commanded the esteem of the historian. Jurists under the Principate were often the servants of expedience or power. Cassius, like the famous Antistius Labeo, was Republican by family and sentiment.
1 [Annals] XIV.43.1: 'melius atque rectius olim provisum et quae converterentur <in> deterius mutari.'
In Cynthia Damon's translation:
Often, senators, have I been in this company when novel senatorial
decrees contrary to our ancestors' institutions and laws have been
demanded. I did not oppose them, not because I doubted that in every
matter former provisions were better and truer and that changes were for the
worse, but lest I seem, with excessive love of ancient custom, to be
promoting my own calling.
saepe numero, patres conscripti, in hoc ordine interfui, cum contra
instituta et leges maiorum nova senatus decreta postularentur; neque sum
adversatus, non quia dubitarem, super omnibus negotiis melius atque rectius olim
provisum et quae converterentur <in> deterius mutari, sed ne nimio amore antiqui
moris studium meum extollere viderer.