As if, in the view of good, brave, and high-minded men, there could be any nobler motive for entering public life than the resolution, not to be ruled by wicked men and not to allow the republic to be destroyed by them.
quasi bonis et fortibus et magno animo praeditis ulla sit ad rem publicam adeundi causa iustior, quam ne pareant inprobis neve ab isdem lacerari rem publicam patiantur
Original text (Latin)
Notes from Wikiquote
De Re Publica [Of The Republic], 1.5 (Keyes tr.).