No tyranny is more cruel than that which is practiced in the shadow of the law and with the trappings of justice: that is, one would drown the unfortunate by the very plank by which he would hope to be saved.

Moreover, no tyrant ever lacks the instruments necessary to his tyranny. Tiberius always found the judge who was prepared to sentence any person of whom he had the slightest suspicion. In the time of the republic the senate, which did not as a body pass judgment on specific transactions, nevertheless, through a delegation of the people, took cognizance of crimes that were imputed to allies. In a like manner, Tiberius referred to this body the adjudication of all crimes which he considered an act of offense against his person.

The senate then fell into a state of utter degradation such as can scarce be described; the senators themselves led the processional into their own enslavement. Under the patronage of Sejanus, the best known among them competed to be informers for the emperor.

–Charles de Secondat, Baron de Montesquieu, Considérations sur les causes de la grandeur des Romains et de leur décadence, ch. xiv (1734) contained in Œuvres complètes, vol. ii, p. 144 (R. Caillois ed. 1951)(S.H. transl.)

This quote is from: https://harpers.org/2010/05/montesquieu-tyranny-in-the-shadow-of-the-law/