They challenged the idea of absolute monarchy and demanded a social contract as the new basis of political authority, and demanded a more democratic organization of central power in a constitutional monarchy, with a separation of powers among the executive, legislative, and judicial branches of government (Montesquieu, Diderot, and Rousseau.) Voltaire fought against the abuses of power by the government, such as censorship and letters of cachet, which allowed imprisonment without trial, against the collusion of the church and monarchy, and for an "enlightened despotism" where kings would be advised by philosophers.