Hello!
Montesquieu contributed the idea of "separation of powers."
Today, the United States government is guided by this principle. The government is separated into three branches:
The Executive branch (The president and his workers)
The Judicial branch (The courts)
The Legislative branch (The Senate and House of Representatives)
The purpose for the separation of powers is to avoid a dictatorship. When the governmental branches are separated, none of them can gain too much power. They each control and balance each other's power (known as checks and balances).
I hope this helps you! Have a fantastic day!