The third book famously discusses the principles of democracy, aristocracy, and monarchy, while the twelfth book discusses the titular concept in relation to those that form political liberty.  
The author of this work declares his philosophical genius with the quote "I have said with Correggio, 'And I also am a painter.'"  Divided into thirty-one chapters, this work discusses the title concept in relation to men in different climates and in relation to the soil.  The third book famously discusses the principles of democracy, aristocracy, and monarchy, while the twelfth book discusses the titular concept in relation to those that form political liberty.  Ending with a history of the Frankish legal system, FTP, identify this work of political philosophy by Charles de Montesquieu.
The author of this work declares his philosophical genius with the quote "I have said with Correggio, '
On the Spirit of the Laws or De l'esprit des lois