Interest against interest

"In the next place, there can scarcely be any other adequate security against encroachments upon the constitutional rights and liberties of the people. Algernon Sidney has said with great force, that the legislative power is always arbitrary, and not to be trusted in the hands of any, who are not bound to obey the laws they make. But it is not less true, that it has a constant tendency to overleap its proper boundaries, from passion, from ambition, from inadvertence, from the prevalence of faction, or from the overwhelming influence of private interests. Under such circumstances, the only effectual barrier against oppression, accidental or intentional, is to separate its operations, to balance interest against interest, ambition against ambition, the combinations and spirit of dominion of one body against the like combinations and spirit of another."
--Joseph Story, Commentaries on the Constitution, § 557