The radical English republican Algernon Sidney (1622-1683) distinguishes between states that have illegitimate de facto power and those that have legitimate de jure power:
No man can have a power over a nation otherwise than de jure, or de facto. He who pretends to have a power de jure, must prove that it is originally inherent in him or his predecessor from whom he inherits; or that it was justly acquired by him. The vanity of any pretence to an original right appears sufficiently, I hope, from the proofs already given, that the first fathers of mankind had it not; or if they had, no man could now inherit the same, there being no man able to make good the genealogy that should give him a right to the succession.
About this Quotation:
The radical English republican Algernon Sidney (1622-1683) was executed by the English crown for writing the subversive political tract Discourses Concerning Government which was posthumously published in 1698. His work went on to have an enormous impact in the North American colonies. One of his key ideas was his notion of “the consent of the governed” which of course would be used in the Declaration of Independence to justify revolt against the British Crown. In his Discourses Sidney argued that a government was legitimate (de jure) only when it had been consented to by those living under its power. By this standard every government that existed lacked legitimacy and only held power “in fact” (de facto), in other words because it had the power to do so and thus was “void of all right.” The difficulty of course was in showing how a government consented to by one generation could claim legitimacy from the generations that came after. One solution to this problem proposed b y Jefferson was to have a new revolution every generation of so to reconfirm this act of consent. David Hume, on the other hand, was quite satisfied with the legitimacy of states which only held power de facto.