It is far safer to be feared than loved. For of men it may generally be affirmed that they are thankless, fickle, false, studious to avoid danger, greedy of gain, devoted to you while you are able to confer benefits upon them, and ready, as I said before, while danger is distant, to shed their blood, and sacrifice their property, their lives, and their children for you; but in the hour of need they turn against you....Men worry less about doing an injury to one who makes himself loved than to one who makes himself feared. The bond of love is one which men, wretched creatures that they are, break when it is to their advantage to do so; but fear is strengthened by a dread of punishment which is always effective.
Machiavelli, The Prince
Everyone realizes how praiseworthy it is for a prince to honour his word and to be straightforward rather than crafty in his dealings; nonetheless contemporary experience shows that princes who have achieved great things have been those who have given their word lightly, who have known how to trick men with their cunning, and who, in the end, have overcome those abiding by honest principles.
Machiavelli, The Prince