By using a system of checks and balances. The Legislative Branch can impeach Supreme Court Justices, and the Executive Branch appoints them. The Judicial Branch can declare certain actions taken by the Executive Branch to be unconstitutional, and can declare laws made by the Legislative Branch unconstitutional. The Executive can veto laws made by the Legislative. The Legislative can impeach the president (Executive Branch). Does this make sense?
John Locke, whose ideas were reflected in the ideas of the founding fathers of the United States, wrote back in 1690 that the natural right of a person is the right for protection of life, freedom and property from threats and encroachment from the outside.