The promotion of natural rights and the sovereignty of the people in politics (the social contract).
Explanation:
The Enlightenment philosophes championed the Scientific Revolution's approach to knowledge, emphasizing the use of reason in all matters, in contrast to following superstition or unquestioningly accepting traditional beliefs.
The Scientific Revolution showed that there are natural laws in place in the physical world and in the universe at large. Applying similar principles to matters like government and society, Enlightenment thinkers believed that using reason will guide us to the best ways to operate politically so we can create the most beneficial conditions for society. For many Enlightenment thinkers, this included a conviction that all human beings have certain natural rights which are to be protected and preserved. This led to changes of approach to how society should be governed -- moving away from ideas like the "divine right of kings" to the establishment of more democratic, constitutional societies. This was the concept of the "social contract," that governments get their authority to govern from the consent of the governed.
Deserts are characteristically deserted and lack an abundance of water, so this dry climate provides a fitting geographic theme for a group of people that learn to survive with a limited water supply.
