Excerpt from the "Second Treatise of Civil Government"

"The reason why men enter into society, is the preservation of their property; and the end why they chuse and authorize a legislative, is, that there may be laws made, and rules set, as guards and fences to the properties of all the members of the society, to limit the power, and moderate the dominion, of every part and member of the society: for since it can never be supposed to be the will of the society, that the legislative should have a power to destroy that which every one designs to secure, by entering into society, and for which the people submitted themselves to legislators of their own making; whenever the legislators endeavour to take away, and destroy the property of the people, or to reduce them to slavery under arbitrary power, they put themselves into a state of war with the people, who are thereupon absolved from any farther obedience, and are left to the common refuge, which God hath provided for all men, against force and violence."

Taken from the Second Treatise of Civil Government by John Locke, 1690.