John Locke's writings(Two Treatises of Government) are of Natural Rights (Life, Liberty and Property) and how its the governments job to protect those rights.
if a government cannot or does not do so, then under his philosophy the people has the right to overthrow the government. (This idea is called "Consent of Governed")
This is shown in the lines Declaration of Independence of "We the People".
Montesquieu's Spirit of Laws advocates for checks and balances in the government and dividing power among branches of the government.