Split the government into three, so no single hand can hold it all. The idea that shaped America came from a French aristocrat watching England.
Separation of powers divides government into three branches: a legislature that makes laws, an executive that enforces them, and a judiciary that interprets them. Each has its own sphere, and no one branch is supposed to do another's job.
The clearest articulation came from the French thinker Montesquieu, whose 1748 work The Spirit of the Laws argued that liberty dies when the same hands hold the power to write, enforce, and judge the law. The framers read him closely.
They built his theory into the Constitution's very structure. Article I creates Congress, Article II the presidency, Article III the courts, in that order, each a separate seat of power with its own source of authority and its own limits.
The goal was not efficiency. A government split three ways is slower and more frustrating than one ruled by a single will. The goal was safety: by dividing power, the framers made it far harder for any person or faction to seize all of it.
