Separation of powers
The separation of powers divides a government into branches - typically legislative, executive and judicial - and assigns each a distinct function, so that no single body both makes the law and enforces it. Montesquieu gave the doctrine its influential modern form in The Spirit of the Laws, drawing on a reading of the English constitution of his day that was disputed even then. The related idea of checks and balances lets each branch block some actions of the others, which the authors of The Federalist defended on the ground that written declarations alone would not restrain ambition.
Why it matters
It is the main institutional answer to the question of how a government strong enough to be useful can be stopped from becoming arbitrary.
Also written: checks and balances, trias politica
Where it comes up
Read about Separation of powers on Wikipedia
Sources
- Constitutionalism Stanford Encyclopedia of Philosophy
- The Federalist No. 51 The Avalon Project, Yale Law SchoolTwo pages, and the clearest statement of why the design does not rely on officials being virtuous.
- Separation of powers Wikipedia
