But, you may say, who will complain of a decree which is passed against traitors to their country? Time, I answer, the lapse of years, and Fortune, whose caprice rules the nations. Whatever befalls these prisoners will be well deserved; but you, Fathers of the Senate, are called upon to consider how your action will affect other criminals. All bad precedents have originated in cases which were good; but when the control of the government falls into the hands of men who are incompetent or bad, your new precedent is transferred from those who well deserve and merit such punishment to the undeserving and blameless.

Julius Caesar (100-44 BC) Roman general and statesman [Gaius Julius Caesar]

In Sallust, The War with Cataline [tr. Loeb Classical Library (1921, rev. 1931)]

Full http://penelope.uchicago.edu/thayer/e/roman/texts/sallust/bellum_catilinae*.html.