Niccolò Machiavelli,
Discourses on Livy (Neville) — Second Book…
(1531)
“ Either you, a Prince, want to keep the people of the City in restraint with these fortresses, or you, a Prince or a Republic, want to keep a City in restraint that has been occupied in war. I want to turn to the Prince, and I say to him that such fortresses cannot be more useless to him in holding his Citizens in restraint for the reasons given above, for it makes you more prompt and less regardful in oppressing them, and that oppression will expose you to your ruin and will excite them so, that that fortress which is the reason for it cannot afterwards defend you ”
