the Roman Republic and the British constitutional system. Montesquieu took the view that the Roman Republic had powers separated so that no one could usurp complete power. In the British constitutional system, Montesquieu discerned a separation of powers among the monarch, Parliament, and the courts of law. Montesquieu argues that each Power should only exercise its own functions. He was quite explicit here: Separation of powers requires a different source of legitimization, or a different act of legitimization from the same source, for each of the separate powers. If the legislative branch appoints the executive and judicial powers, as Montesquieu indicated, there will be no separation or division of its powers, since the power to appoint carries with it the power to revoke. Montesquieu actually specified that the independence of the judiciary has to be real, and not merely apparent. The judiciary was generally seen as the most important of the three powers, independent and unchecked. Checks and balances According to the principle of checks and balances, each of the branches of the state should have the power to limit or check the other two, creating a balance between the three separate powers of the state. Each branch's efforts to prevent either of the other branches becoming supreme form part of an eternal conflict, which leaves the people free from government abuses. Immanuel Kant was an advocate of this, noting that "the problem of setting up a state can be solved even by a nation of devils" so long as they possess an appropriate constitution to pit opposing factions against each other. Checks and balances are designed to maintain the system of separation of powers keeping each branch in its place. The idea is that it is not enough to separate the powers and guarantee their independence but the branches need to have the constitutional means to defend their own legitimate powers from the encroachments of the other branches. They guarantee that the branches have the same level of power (co-equal), that is, are balanced, so that they can limit each other, avoiding the abuse of power. The origin of checks and balances, like separation of powers itself, is specifically credited to Montesquieu in the Enlightenment (in The Spirit of the Laws, 1748). Under this influence it was implemented in 1787 in the Constitution of the United States. In Federalist No. 78, Alexander Hamilton, citing Montesquieu, redefined the judiciary as