Kings, as Montesquieu points out, are less envied than aristocracies; for the king is too far above most of his subjects to excite comparisons, while the nobility is not so placed. Republics, where birth confers no privileges, are, he thinks, happier in this respect than other countries; for the people can envy but little an authority which it grants and withdraws at its pleasure. Montesquieu forgets that every chance to rise which excites in the strong and virtuous a noble emulation, will cause in the weak and sour the corresponding base passion of envy. Complete despotism he believes to be impossible. There is in every nation a general spirit on which all power is founded. Against this, the ruler is powerless. It is wise not to disturb established forms and institutions, for the very causes which have made them last hitherto may maintain them in the future, and these causes are often complicated and unknown. When the system is changed, theoretic difficulties may be overcome, but drawbacks remain which only use can show. It is folly in conquerors to wish to make the conquered adopt new laws and customs, and it is useless; for under any form of government, subjects can obey. Men are never more offended than when their ceremonies and customs are interfered with. Oppression is sometimes a proof of the esteem in which they are held; interference with their customs is always a mark of contempt.[Footnote: Montesq., ii. 181, 315, 316, 266, 174, 209.] Such are some of the general opinions of Montesquieu, found in the "Greatness and Decadence of the Romans." In the same book occurs the expression of an idea (afterwards repeated and worked out), which was to be perhaps the most fruitful of his teachings. "The laws of Rome," he says, "had wisely divided the public power among a great number of offices, which sustained, arrested, and moderated each other; and as each had but a limited power, every citizen was capable of attaining to any one of them; and the people, seeing several persons pass before it one after the other, became accustomed to none of them."[Footnote: Ibid., ii. 200.]