Charles Louis de Secondat was born in Bordeaux, France, in 1689 to a wealthy family. Despite his family's wealth, de Decondat was placed in the care of a poor family during his childhood. He later went to college and studied science and history, eventually becoming a lawyer in the local government. De Secondat's father died in 1713 and he was placed under the care of his uncle, Baron de Montesquieu. The Baron died in 1716 and left de Secondat his fortune, his office as president of the Bordeaux Parliament, and his title of Baron de Montesquieu. Later he was a member of the Bordeaux and French Academies of Science and studied the laws and customs and governments of the countries of Europe. He gained fame in 1721 with his Persian Letters, which criticized the lifestyle and liberties of the wealthy French as well as the church. However, Montesquieu's book On the Spirit of Laws, published in 1748, was his most famous work. It outlined his ideas on how government would best work.

      Montesquieu believed that all things were made up of rules or laws that never changed. He set out to study these laws scientifically with the hope that knowledge of the laws of government would reduce the problems of society and improve human life. According to Montesquieu, there were three types of government: a monarchy (ruled by a king or queen), a republic (ruled by an elected leader), and a despotism (ruled by a dictator). Montesquieu believed that a government that was elected by the people was the best form of government. He did, however, believe that the success of a democracy - a government in which the people have the power - depended upon maintaining the right balance of power.

      Montesquieu argued that the best government would be one in which power was balanced among three groups of officials. He thought England - which divided power between the king (who enforced laws), Parliament (which made laws), and the judges of the English courts (who interpreted laws) - was a good model of this. Montesquieu called the idea of dividing government power into three branches the "separation of powers." He thought it most important to create separate branches of government with equal but different powers. That way, the government would avoid placing too much power with one individual or group of individuals. He wrote, "When the [law making] and [law enforcement] powers are united in the same person... there can be no liberty." According to Montesquieu, each branch of government could limit the power of the other two branches. Therefore, no branch of the government could threaten the freedom of the people. His ideas about separation of powers became the basis for the United States Constitution.

      Despite Montesquieu's belief in the principles of a democracy, he did not feel that all people were equal. Montesquieu approved of slavery. He also thought that women were weaker than men and that they had to obey the commands of their husband. However, he also felt that women did have the ability to govern. "It is against reason and against nature for women to be mistresses in the house... but not for them to govern an empire. In the first case, their weak state does not permit them to be preeminent; in the second, their very weakness gives them more gentleness and moderation, which, rather than the harsh and ferocious virtues, can make for a good environment." In this way, Montesquieu argued that women were too weak to be in control at home, but that there calmness and gentleness would be helpful qualities in making decisions in government.