The Spirit of Laws (1750), or L'Esprit des lois, a treatise consisting of thirty-one books written by the French philosopher Montesquieu, is considered by many a landmark contribution to political theory.
Montesquieu divides governments into three types: republics, monarchies, and despotisms. Montesquieu associates each of the three types of government with a primary principle: the republic with virtue, monarchy with honor, and despotism with fear. For Montesquieu, the type of government is determined not by the form of rule but by the way in which rule is exercised. For this reason, he distinguishes between a monarchy, where a complex of institutions, men of politics, and honor lead to the role of law, from a despotism, where everyone is essentially a slave of the ruler. Montesquieu, using the English governments as a model, sees the separation of powers as a guarantor of political liberty.
Montesquieu devotes the first few chapters of the treatise to the distinction between the law and the spirit of the law. He then considers the principles behind each form of government and the law as it relates to those principles. Next, he examines the relationship between laws and political liberty. He then considers the impact of climate and terrain on the laws of a given nation and the nation’s general spirit and manners. Next, he relates laws to economic and religious systems. Finally, he launches into a historical examination of laws in different contexts, with a focus on the French context.
For a more detailed summary, see the third link below.
The full work in English translation is available at the second link below.
In terms of its practical effect, The Spirit of the Laws is one of the most important political science books. It was one of the primary sources of the United States Constitution and, through that document, one of the major influences on the development of democratic institutions in Europe during and after the French Revolution. All this is out of proportion to Montesquieu’s objectives in writing the book, which were to analyze the various types of political institutions known throughout the world throughout history. Montesquieu also aims, in his book, to denounce the abuses of the French monarchical system and to encourage a liberal and more equitable monarchical government for France.
In setting out to write his book, Montesquieu’s major inspirations were the works of René Descartes, Nicholas de Malebranche, and Niccolò Machiavelli, all of which he viewed with the kind of healthy skepticism typical of Michel Eyquem de Montaigne. This inspiration did not give him his conclusions, but it gave him his method: a rational, descriptive, and analytic approach to the problem of the nature of the good constitution of society. Montesquieu, like most early political thinkers after Machiavelli, was essentially concerned with the problem of the relationship of right and might, of law and power. Many of these thinkers, however, especially those opposed to what they considered the evil in Machiavelli’s realistic approach to politics, tried to theorize on a moral base. They sought to find the basis for the right constitution of society in a consideration of right and wrong and in a natural law of right and wrong. Such an approach was alien to Montesquieu. Political society, for him, had to be based on civil law. Law should reflect what individuals consider right or wrong, but subjective morals and objective law are two different things. Morals, like law, are relative; what one society might consider both right and legal, another might well consider both wrong and illegal.
In considering the problem of adjusting right and might, law and power, Montesquieu did not attempt to solve the problem. He was convinced the problem could not be solved but only understood and dealt with in more rational and equitable ways than societies had used in the past. Thus, he was no more a political moralist than he was a political utopian....
(The entire section is 2,064 words.)