VC Philosophy of Human Nature Behind the Phrase Discussion

I’m working on a history multi-part question and need an explanation to help me study.

Explain the philosophy of human nature behind the phrase “Ambition must be made to counteract ambition” in The Federalist #51. How were these words put to use in the checks and balance system (include shared powers here)? Explain how separate branches with different constituencies along with separate elections were designed to put into effect the check and balance mentioned by Madison in Federalist #51. How does a Federal Republic serves as a check and balance according to Madison? How effective do you think our current system of checks and balances is?