The Spirit of The Laws - Liberty and The Separation of Powers

Liberty and The Separation of Powers

A second major theme in De l'esprit des lois 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 insofar as this is provided for through a system of dependable and moderate laws. He distinguishes this view of liberty from two other, misleading 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 thinks, 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 restrained by the other branches. (Habeas Corpus is an example of a check that the Judiciary branch has on the Executive branch of government.) In a lengthy discussion of the English political system, he tries to show how this might be achieved and liberty secured, even in a monarchy. He also notes that liberty cannot be secure where there is no separation of powers, even in a republic.

• The appropriate framing of civil and criminal laws so as to ensure personal security.

Montesquieu intends what modern legal scholars might call the rights to "robust procedural due process", including the right to a fair trial, the presumption of innocence and the proportionality in the severity of punishment. Pursuant to this requirement to frame civil and criminal laws appropriately to ensure political liberty (i.e., personal security), Montesquieu also argues against slavery and for the freedom of thought, speech and assembly.