and despotism hinges on whether or not a fixed set of laws exists that can restrain the authority of the ruler: if so, the regime counts as a monarchy; if not, it counts as despotism. Principles that motivate citizen behavior according to Montesquieu Driving each classification of political system, according to Montesquieu, must be what he calls a "principle". This principle acts as a spring or motor to motivate behavior on the part of the citizens in ways that will tend to support that regime and make it function smoothly. For democratic republics (and to a somewhat lesser extent for aristocratic republics), this spring is the love of virtue—the willingness to put the interests of the community ahead of private interests. For monarchies, the spring is the love of honor—the desire to attain greater rank and privilege. Finally, for despotisms, the spring is the fear of the ruler—the fear of consequences to authority. A political system cannot last long if its appropriate principle is lacking. Montesquieu claims, for example, that the English failed to establish a republic after the Civil War (1642–1651) because the society lacked the requisite love of virtue. Liberty and the separation of powers A second major theme in The Spirit of Law concerns political liberty and the best means of preserving it. "Political liberty" is Montesquieu's concept of what we might call today personal security, especially in so far as this is provided for through a system of dependable and moderate laws. He distinguishes this view of liberty from two other views of political liberty. The first is the view that liberty consists in collective self-government—i.e. that liberty and democracy are the same. The second is the view that liberty consists in being able to do whatever one wants without constraint. Not only are these latter two not genuine political liberty, he maintains, but they can both be hostile to it. Political liberty is not possible in a despotic political system, but it is possible, though not guaranteed, in republics and monarchies. Generally speaking, establishing political liberty on a sound footing requires two things: The separation of the powers of government. Building on and revising a discussion in John Locke's Second Treatise of Government, Montesquieu argues that the executive, legislative, and judicial functions of government should be assigned to different bodies, so that attempts by one branch of government to infringe on political liberty might be