Charles de Secondat, Baron de Montesquieu researched and wrote about a wide range of disciplines and issues including the law, social life and anthropology. He mainly wrote about and in support of constitutional theory and constitutional systems, principles of governance and separation of powers. His other key areas were slavery, preservation of civil liberties and the law and the reflection of social and geographical aspects in political and government institutions.
For more than 20 years, Montesquieu researched and wrote about issues of constitutional theory, separation of powers and liberty, climate, culture and broader societal issues. The motivational factors and principles of human behavior were of specific interest or focus in his works. One such principle is the need, desire and willingness to place people's or communal rights and interests ahead of private interests. This principle is particularly true and desirable in democratic societies. He wrote that while motivation comes from the desire for greater rank, power and privilege for monarchs and monarchies, fear of the ruler is the main motivator of human behavior for despots. Montesquieu also wrote about the importance of these principles for the existence of political systems. Finally, he emphasized the need for the love of virtue for stable and strong societies.