Why were several rulers in 18th century Europe known as enlightened despots?

Several rulers in 18th century Europe were known as enlightened despots because they were European monarchs who were inspired by Enlightenment ideas to rule justly and respect the rights of their subjects.

Frederick the Great is an example of an enlightened despot. He unified, rationalized and modernized Prussia. He revamped and standardized Prussia's justice system. He banned torture and argued for a uniform national criminal code. He supported moderate level of religious freedom and liberalized control of the press. He lowered internal duties in Prussia and built canals to encourage trade and enact protective tariffs. He built up Berlin as a cultural capital with grand buildings and rejuvenated the Berlin Academy for its scientific work.