John Locke, Second Treatise on Civil Government: Section 227
In both the fore-mentioned cases, when either the legislative is changed, or the legislators act contrary to the end for which they were constituted; those who are guilty are guilty of rebellion: for if any one by force takes away the established legislative of any society, and the laws by them made, pursuant to their trust, he thereby takes away the umpirage, which every one had consented to, for a peaceable decision of all their controversies, and a bar to the state of war amongst them. They, who remove, or change the legislative, take away this decisive power, which no body can have, but by the appointment and consent of the people; and so destroying the authority which the people did, and no body else can set up, and introducing a power which the people hath not authorized, they actually introduce a state of war, which is that of force without authority: and thus, by removing the legislative established by the society, (in whose decisions the people acquiesced and united, as to that of their own will) they untie the knot, and expose the people a-new to the state of war, And if those, who by force take away the legislative, are rebels, the legislators themselves, as has been shewn, can be no less esteemed so; when they, who were set up for the protection, and preservation of the people, their liberties and properties, shall by force invade and endeavour to take them away; and so they putting themselves into a state of war with those who made them the protectors and guardians of their peace, are properly, and with the greatest aggravation, rebellantes, rebels.